electrical testing procedures

8/6/2019 Electrical Testing Procedures

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GK Batchelor Laboratory

Department of Applied Mathematics and Theoretical Physics

UNIVERSITY OF CAMBRIDGE

Elec t r ic a l Safet y :

Pol ic y and Proc edures

Contents

1 Scope .......................................................................................................................... 5

2 Use of Equipment....................................................................................................... 5

2.1 Policy................................................................................................................... 5

2.1.1 Offices.......................................................................................................... 52.1.2 Laboratory .................................................................................................... 5

2.1.3 Laptops......................................................................................................... 5

2.1.4 Home office.................................................................................................. 6

2.2 Testing................................................................................................................. 6

2.3 Auditing............................................................................................................... 7

2.4 Rig Risk Assessment........................................................................................... 7

2.5 Elemental Risk Assessment ................................................................................ 8

2.6 Operating Procedures .......................................................................................... 8

2.7 Standard Procedures............................................................................................ 9

2.7.1 Positioning of Equipment............................................................................. 9

2.7.2 RCD Protection ............................................................................................ 92.7.3 Switching...................................................................................................... 9

2.7.4 Extension leads and plug boards ................................................................ 10

2.7.5 Earth bonding............................................................................................. 10

2.7.6 Submersible equipment.............................................................................. 10

2.8 Faults ................................................................................................................. 11

2.9 Disposal ............................................................................................................. 11

2.10 People .............................................................................................................. 11

2.10.1 User .......................................................................................................... 11

2.10.2 Electrical Safety Assessor ........................................................................ 11

3 Tests ......................................................................................................................... 11

3.1 Brand New Equipment ...................................................................................... 113.2 Equipment from Other Sources......................................................................... 12

3.3 Standard Tests ................................................................................................... 12

3.3.1 Cable damage ............................................................................................. 12

3.3.2 Casing damage and condition .................................................................... 12

3.3.3 Fuse rating.................................................................................................. 12

3.3.4 Earth bond .................................................................................................. 12

3.3.5 Insulation.................................................................................................... 13

3.3.6 Operational................................................................................................. 13

3.3.7 Earth leakage.............................................................................................. 13

3.4 Flash Tests ......................................................................................................... 13

3.5 Supplementary Tests ......................................................................................... 13

4 Documentation ......................................................................................................... 14


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4.1 Record Sheet ..................................................................................................... 14

4.2 Test Sticker........................................................................................................ 14

4.3 Database ............................................................................................................ 14

5 Office Equipment ..................................................................................................... 15

5.1 Office Appliances.............................................................................................. 15

5.1.1 Desk lamps ................................................................................................. 155.1.2 Fans ............................................................................................................ 15

5.1.3 Heaters........................................................................................................ 15

5.2 Kitche and Cleaning .......................................................................................... 16

5.2.1 Kettles......................................................................................................... 16

5.2.2 Microwaves ................................................................................................ 16

5.2.3 Vacuum cleaners ........................................................................................ 16

5.3 IT Equipment..................................................................................................... 17

5.3.1 Computers .................................................................................................. 17

5.3.2 Computer monitors..................................................................................... 17

5.3.3 Laptops....................................................................................................... 18

5.3.4 Printers ....................................................................................................... 185.3.5 Data hubs.................................................................................................... 18

5.4 Communication Equipment............................................................................... 19

5.4.1 Answerphones and dictation machines ...................................................... 19

5.4.2 Fax machines.............................................................................................. 19

5.5 Reproduction Equipment................................................................................... 19

5.5.1 Photocopiers............................................................................................... 19

5.5.2 Binders ....................................................................................................... 19

5.6 Projection Equipment........................................................................................ 20

5.6.1 Slide projectors........................................................................................... 20

5.6.2 Overhead projectors ................................................................................... 20

5.6.3 Data projectors ........................................................................................... 20

Video tape recorders............................................................................................ 21

6 General Equipment................................................................................................... 21

6.1 Catering Equipment........................................................................................... 21

6.2 Plant................................................................................................................... 21

6.3 Lighting and Sockets......................................................................................... 21

7 Laboratory Equipment.............................................................................................. 21

7.1 Office Appliances.............................................................................................. 21

7.1.1 Desk lamps ................................................................................................. 21

7.1.2 Fans ............................................................................................................ 22

7.1.3 Vacuum cleaners ........................................................................................ 227.2 Laboratory Appliances ...................................................................................... 22

7.2.1 Densitometer .............................................................................................. 22

7.2.2 Refrigerator ................................................................................................ 23

7.2.3 Freezer........................................................................................................ 23

7.3 IT Equipment..................................................................................................... 23

7.3.1 Computers .................................................................................................. 23

7.3.2 Computer monitors..................................................................................... 24

7.3.3 Printers ....................................................................................................... 24

7.3.4 Data hubs.................................................................................................... 24

7.3.5 Portable equipment..................................................................................... 25

7.4 Video Equipment and Cameras......................................................................... 257.4.1 Video tape recorders................................................................................... 25


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7.4.2 Video monitors........................................................................................... 25

7.4.3 Video timers ............................................................................................... 26

7.4.4 High-speed cine camera ............................................................................. 26

7.4.5 Video cameras............................................................................................ 26

7.4.6 Camera power supplies .............................................................................. 27

7.5 Light Sources..................................................................................................... 277.5.1 Projectors.................................................................................................... 27

7.5.2 Photographic lamps.................................................................................... 28

7.5.3 Turntable lamps.......................................................................................... 28

7.5.4 Fluorescent lamps....................................................................................... 29

7.5.5 Light boxes................................................................................................. 30

7.5.6 Arc lamps ................................................................................................... 30

7.5.7 Strobe lights ............................................................................................... 31

7.6 Lasers ................................................................................................................ 31

7.7 Power Supplies.................................................................................................. 31

7.7.1 Bench supplies ........................................................................................... 31

7.7.2 Plug-in adapters.......................................................................................... 327.7.3 High voltage supplies ................................................................................. 32

7.8 Laboratory Instrumentation............................................................................... 33

7.8.1 Amplifiers................................................................................................... 33

7.8.2 Bridge circuits ............................................................................................ 34

7.8.3 Multimeters ................................................................................................ 34

7.8.4 Oscilloscopes.............................................................................................. 34

7.8.5 High voltage equipment ............................................................................. 35

7.9 Motors and Controllers...................................................................................... 36

7.9.1 Servo motor controllers.............................................................................. 36

7.9.2 Servo motors .............................................................................................. 36

7.9.3 AC motors .................................................................................................. 36

7.10 Pumps.............................................................................................................. 37

7.10.1 Integrated pumps...................................................................................... 37

7.10.2 Peristaltic pumps ...................................................................................... 37

7.10.3 Submersible pumps .................................................................................. 38

7.10.4 Vacuum pumps......................................................................................... 38

7.10.5 Double-bucket pumps .............................................................................. 38

7.10.6 Variable speed pumps .............................................................................. 39

7.11 Turntables........................................................................................................ 39

7.11.1 Turntables................................................................................................. 39

7.12 Laboratory Equipment..................................................................................... 407.12.1 Heat baths................................................................................................. 40

7.12.2 Stirrers ...................................................................................................... 40

7.12.3 Scales........................................................................................................ 41

7.12.4 Immersion heaters .................................................................................... 41

7.13 Frameworks and Tanks ................................................................................... 41

7.13.1 Metalwork ................................................................................................ 41

7.14 Power Cords .................................................................................................... 42

7.14.1 Standard cords (IEC)................................................................................ 42

7.14.2 Non-standard cords .................................................................................. 43

7.14.3 Cords with RCD....................................................................................... 43

7.15 Plug-boards and Extension Leads ................................................................... 437.15.1 Plug-boards............................................................................................... 43


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7.15.2 Integrated plug-boards.............................................................................. 44

7.15.3 Extension Leads ....................................................................................... 44

7.16 RCDs............................................................................................................... 45

7.16.1 RCD adapters ........................................................................................... 45

7.16.2 RCD plugs................................................................................................ 45

7.16.3 RCD sockets............................................................................................. 457.17 Fixed Installations ........................................................................................... 45

7.17.1 Hand driers ............................................................................................... 45

7.17.2 Heaters...................................................................................................... 46

7.18 Three-phase Installations................................................................................. 46

7.18.1 Wind tunnels ............................................................................................ 46

7.18.2 Flumes...................................................................................................... 46

7.18.3 Sump pump .............................................................................................. 46

7.18.4 Ventilation equipment.............................................................................. 47

8 Workshop ................................................................................................................. 47

8.1 Hand Tools ........................................................................................................ 47

8.1.1 Drills........................................................................................................... 478.1.2 Grinders...................................................................................................... 47

8.1.3 Saws ........................................................................................................... 48

8.1.4 Routers ....................................................................................................... 48

8.1.5 Heat guns.................................................................................................... 49

8.1.6 Soldering irons ........................................................................................... 49

8.2 Fixed Tools........................................................................................................ 49

Three Years ......................................................................................................... 49

8.3 Three-phase Installations................................................................................... 50

8.3.1 Milling machines........................................................................................ 50

8.3.2 Lathes ......................................................................................................... 50

8.3.3 Drilling machines....................................................................................... 50

8.3.4 Compressor ................................................................................................ 50

8.3.5 Abrasion tools ............................................................................................ 51


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1 Scope

This document outlines the various procedures, responsibilities, and risks

associated with the use of mains-operated electrical equipment in the Fluid

Dynamics Laboratory. The document provides guidance for the development of

Risk Assessments, and describes the various test procedures and hazards

associated with the main classes of equipment used in the Laboratory and

Workshop.

NOTE: A replacement for this document is under preparation. A draft of the

new CMS Site Policy may be found at

http://www.damtp.cam.ac.uk/lab/safety/ElectricalDraftPolicy.pdf

2 Use of Equipment

2.1POLICY

2.1.1 Offices

No mains-operated electrical or electronic equipment may be used unless it has a

valid test sticker issued by the Department. Test stickers from other sources are

not acceptable alternatives. This requirement applies to all office equipment and

domestic appliances, including computers and even if they are brand new. Any

equipment that has been modified or is not standard equipment must be subject to

the procedures and standards outlined for laboratory equipment.

The user must be familiar with the manufacturers instructions for the equipment

and use it in accordance with these.

Failure to observe these procedures may result in sanctions or disciplinary actionagainst the offender.

2.1.2 Laboratory

No mains-operated electrical or electronic equipment may be used unless it has a

valid test sticker issued by the Department and a Risk Assessment has been

carried out. Test stickers from other sources are not acceptable alternatives, and

stickers are required even for brand new equipment. The user must have read and

be familiar with the Operational Procedures for the equipment. The user must also

be familiar with and adhere to the general guidance and procedures given in the

Laboratory Safety Guidelines and the specific procedures outlined below.

Failure to observe these procedures may result in sanctions or disciplinary action

against the offender.

2.1.3 Laptops

All laptops purchased or owned by the Department must be tested in accordance

with this policy, even if the laptop is never used within the Department itself.

Testing should include inspection of any multi-standard mains adapter that may

be used with the laptop.

When outside the Department, users should only connect to the mains if they are

confident that the electrical outlet is safe and that their laptop is not damaged.
http://www.damtp.cam.ac.uk/lab/safety/ElectricalDraftPolicy.pdfhttp://www.damtp.cam.ac.uk/lab/safety/ElectricalDraftPolicy.pdfhttp://www.damtp.cam.ac.uk/lab/safety/ElectricalDraftPolicy.pdf


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Visitors from outside the Department are requested not to connect their laptops

unless they have been tested to a level comparable to that outlined in this

document. The Department is happy to test laptops for long-term visitors. It is

recommended that short-term visitors run their laptops from batteries. The

Department does not condone the use of laptops that have not been tested and

cannot be held liable for any injury, damage or other consequence of failing toobserve this guideline.

2.1.4 Home office

Some members of staff have equipment (primarily IT equipment) in their own

homes where this equipment is purchased out of departmental or research funds.

The responsibility for ensuring that this equipment is tested regularly (typically

every three years) falls solely on the user of such equipment. The Department will

test such equipment if the user brings it into the Department for testing. The

Department will also test other equipment that is used predominantly for work at

home, even when it is not owned by the Department, provided it is brought into

the Department for testing.

Users should adhere to the same level of standards in both the home office and

Departmental contexts. This includes but is not limited to Electrical Safety and the

Universitys guidelines for the use of VDU screen equipment.

The Department cannot be held responsible for loss or injury resulting from

failure to adhere to this guideline or from failure to ensure the equipment is tested

regularly.

2.2TESTING

Prior to 2000, the test stickers on items of equipment indicated only the date the

equipment was last tested. From July 2000 onwards, the stickers indicate both thedate tested, and the date the next test is due. With the older type of stickers, the

user should seek verification that the equipment is still safe to use for any

equipment where the date is more than two years before the present. For the

newer style of sticker, equipment must not be used beyond the next test due

date.

For equipment where the mains power cable is not integral, both the cable and the

equipment itself should have a valid test sticker.

Brand new items, and equipment sourced from elsewhere must also be issued with

test stickers. The equipment must not be used until this has been completed. The

level of testing required for this is detailed elsewhere in this document.

In the Risk Assessment for a laboratory experiment, the user must list all electrical

equipment and record the next test due date for each item. It is the responsibility

of the user to react accordingly when this due date is approaching. It is

recommended that a re-test is requested four weeks before the due date. Note that

failure to request testing at least three weeks in advance of the due date may lead

to delays in the experimental programme while awaiting for a test to be

undertaken.

The user should also complete a visual inspection of all equipment on a regular

basis. Any defective, damaged or otherwise unsafe equipment should be

disconnected immediately and the reason for the disconnection indicated on the


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equipment. Notices for indicating faults are available from the Electronics

Technician. The defect should also be reported to the Electronics Technician.

Not all equipment will be subject automatically to regular testing. The testing of

items that have not been used for a long time, or are only used infrequently, may

be allowed to lapse to avoid unnecessary testing. It is the responsibility of the

user to check that the testing is up to datebefore connecting the equipment.

2.3AUDITING

All equipment in active use will be audited on a regular basis. For equipment in

the Laboratory and Workshop, this auditing will occur every six months. For

equipment in the offices, this auditing will occur annually.

Typically, an audit will involve inspecting a subset of equipment to ensure the

relevant procedures have been adhered to.

During an audit (or at any other time), any equipment found not to have a valid

test sticker, found not to meet standard practices, or found to have an obvious

defect, must be disconnected immediately. Such equipment must not be

reconnected until it has been tested and any problems have been rectified. The

Safety Officer must be informed of all such equipment. In most cases, failure

during an audit will trigger a more detailed examination of any associated

equipment.

2.4RIG RISK ASSESSMENT

A Risk Assessment must always be undertaken for an experimental rig. This Rig

Risk Assessment is normally developed by the user or potential user of the rig,

often in consultation with previous users or other Laboratory personnel. The Rig

Risk Assessment may draw upon details contained in the Risk Assessment forother similar rigs; when this occurs, this link should be spelt out explicitly in the

assessment.

The scope of this Rig Risk Assessment is not limited to electrical equipment, but

must include the full range of mechanical, chemical, light and other potential

hazards.

This Rig Risk Assessment must list each of the items of electrical equipment used

in the rig, and the date at which they are next due to be tested must be recorded.

The Rig Risk Assessment should highlight all potential risks, safe operating

procedures, safe methods in which the rig may be shutdown, and the risk posed

through any equipment connected via signal or data cables. The Rig RiskAssessment must be completed before the experimental rig is first used, and

reviewed or revised whenever there is any material change in the set-up. The

adequacy of the Rig Risk Assessment and the overall safety of the experimental

rig must be reviewed by an Electrical Safety Assessor prior to any work being

undertaken.

The Rig Risk Assessment must also contain a copy of or explicit reference to the

Risk Assessment for any individual component that requires a separate Elemental

Risk Assessment, and any limitations of use or recommended practice contained

in such a separate assessment must be observed.


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Such separate Elemental Risk Assessments are required for all discrete electrical

components that are custom-built, modified in any way, or used in a manner or for

a purpose differing from that envisaged by the manufacturer.

All queries concerning electrical safety should be directed to the Director of the

Laboratory or the Electronics Technician. The Electronics Technician will

normally undertake any electrical tests required.

2.5ELEMENTAL RISK ASSESSMENT

An Elemental Risk Assessment should be completed for every custom-made or

modified item of equipment. Elemental Risk Assessments are also required for

standard items of equipment when such an item is to be operated in am manner

not envisioned by the manufacturer, although such assessments may be derived

from the manufacturers documentation.

The Elemental Risk Assessment should indicate the potential hazards associated

with the equipment, its intended use, the tests to which the equipment should be

subject, the interval for testing, and verification that the Operating Procedures arevalid and appropriate. Generic Elemental Risk Assessments are permitted for

standard laboratory items (e.g. conductivity bridges) even when there may be

some small differences between each individual example.

Elemental Risk Assessments for custom equipment should be reviewed at an

interval of two years, or twice the test interval, whichever is longer. A review is

also required whenever the equipment is modified, or it is to be used in a

substantially different manner.

These Elemental Risk Assessments do not replace the need for a Rig Risk

Assessment.

2.6OPERATING PROCEDURES

All users should consult the Operating Procedures for an item of equipment before

using the equipment. Moreover, if the Operating Procedures or Risk Assessment

specifies that training is required, the use must seek and obtain this training.

For standard commercial equipment, the manufacturers operating procedures are

all that is required,providedthe equipment is to be used for the purpose envisaged

by the manufacturer. Any deviation to this requires supplementary Operating

Procedures to be developed and, potentially, an Elemental Risk Assessment.

All custom-made equipment requires Operating Procedures to be written. These

procedures may be developed during the first six months followingcommissioning, provided the Laboratory Safety Officer deems the user

competent. In such cases, the user will be responsible for developing the

Operating Procedures and will be required to submit a first draft of these

procedures to the Laboratory Safety Officer within two months of the equipment

being commissioned.

Items that are identical or similar to items for which Operating Procedures already

exist may refer to the existing procedures only after those procedures have been

reviewed.

Where possible, all operating procedures should be provided in both electronic

and hard copy. Where the source documentation is electronic, both the source file

(TEX, Word or plain text) and a PostScript or Acrobat version must be logged


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with the Laboratory Safety Officer. Electronic copy in Acrobat format may be

created from hardcopy by the use of a suitable scanner.

2.7STANDARD PROCEDURES

This section lists various standard procedures that must be adhered to for the

majority of equipment. If any of these procedures is to be waived, the reasons fordoing so and the associated risks must be discussed explicitly in the Rig Risk

Assessment.

Spills of water are inevitable in the laboratory. If such spills occur over or close to

electrical or electronic equipment then this represents a serious risk of

electrocution. The standard procedures listed here will help reduce the risk to an

acceptable level.

2.7.1 Positioning of Equipment

Mains operated equipment must be positioned where it is not subject to splashes,

chemicals spills, or other potentially hazardous contamination.When located above water (or any other fluid), it must be fastened in such a way

to prevent any chance of it falling into the fluid. Where possible, avoid mounting

any item below a source of water. If this is unavoidable (e.g. some electric motors

or pumps) careful consideration must be given to minimise the chance of the

water reaching live connections.

The equipment must not be located where it is likely to fall or otherwise suffer

mechanical damage. Where necessary, the technicians will make special brackets

to hold the equipment securely.

2.7.2 RCD Protection

All equipment should be connected to the mains only through a Residual Current

Device (RCD). These devices are designed to immediately cut the supply as soon

as any imbalance occurs between the live and neutral wires, or when any current

is detected in the earth wire. Note that this does not completely remove the chance

of electrocution, but does decrease it significantly.

The RCD should be installed as the first component when connecting to the

mains. Where possible, wall-mounted RCD sockets should be employed. If this is

not possible, RCD plugs or RCD adapters (in that order of preference) should be

used. There is no harm (but also no advantage) in having more than one RCD in

the circuit to a given item of electrical equipment.

RCDs should be checked at least once a month using their integrated test

facility.

Computer equipment may be connected without an RCD unless there is a chance

that it may be exposed to splashes. As a rule, computer equipment should always

be located where there is no chance of such exposure. Note, however, that if the

computer is in any way connected to a probe or control circuit, then an RCD is

required.

2.7.3 Switching

Never turn off, connect or disconnect equipment when your hands are wet, orwhen standing on a wet floor.


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Similarly, do not operate equipment with wet hands or when you are in contact

with water unless the equipment has been designed to allow safe operation when

wet. In such cases, the need for such operation and the risks involved must be

assess in the Risk Assessment.

Ensure the power to the equipment may be safely shut off in the event of an

accident. This should be marked clearly as it may be necessary for someone

unfamiliar with the equipment or rig to do so.

Any cut-out switch should be of a type that may be operated safely with wet

hands. Operation of the cut-out switch should be tested at six-month intervals.

2.7.4 Extension leads and plug boards

Extension leads and plug boards may be used to provide a suitable number and

location of electrical sockets.

No more than one additional plug board may be connected to a plug board.

The total electrical load on the plug board must not exceed the rating of the plugboard, and the total electrical load on a given double socket must not exceed 20A.

Plug boards must be positioned where there is no danger of them being splashed,

stood on, or likely to be immersed in the event of an accidental spillage.

Cables leading both too and from the plug board must be kept tidy and routed to

ensure they do not represent a risk of entanglement. Cables must not be under

strain, and nor should they be of excessive length.

Double adapters must never be used.

2.7.5 Earth bonding

All permanent and substantial equipment containing exposed metalwork must be

earth bonded. Earth bonding consists of providing wires, straps or other direct

electrical connection between each piece of metal, and connecting this into a good

earth.

The Electrical Safety Assessor will check the integrity of these connections.

2.7.6 Submersible equipment

Submersible equipment such as pumps and immersion heaters must only should

preferably be used in tanks where a suitable route to earth is provided. This route

to earth may be provided by an earth connection on the submersible unit, by earth

bonding of metal work exposed to the water, or by the insertion of an earthelectrode into the tank.

If the earth connection is provided by a separate electrode, then this electrode

should be positioned so that it has at least 200mm2

contact with the working fluid

when the fluid is at the lowest level likely to be encountered.

The earth electrode must be kept clean and free from corrosion. It is

recommended that the electrode be constructed from stainless steel and is located

at the bottom of a tank side wall (location on the tank floor may allow an

insulating layer of particles to form on top of the electrode).

The earth electrode must be connected to a suitable earth. For fixed installations,this should be a permanent route to earth. For moveable equipment, it is


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recommended that the connection be made through the same RCD-protected

circuit as the electrical equipment used with the tank. This connection may be

through a dedicated earth terminal on the electrical equipment, or using an

adapted earth-only mains plug inserted into a socket.

2.7.6.1 Faults

Any instances of blown fuses either in the plugs or in the equipment must be

reported to the Electronics Technician. The equipment must be inspected by the

Technician to ascertain the causepriorto the fuse being replaced.

Any instances of the local RCD tripping must be reported to the Electronics

Technician. All the equipment on the circuit that tripped, or any other equipment

connected to this through signal cables, must be inspected by the Technician to

ascertain the causepriorto any of the equipment on the tripped circuit being used

again.

Any instances of thermal cut-outs operating must be reported to the Electronics

Technician. The equipment must be inspected by the Technician to ascertain thecausepriorto any of the equipment being used again.

2.8DISPOSAL

If an item of equipment is sold, given away or otherwise disposed of, the

equipment must be marked with a sticker stating that it has not been electrically

tested and that it is the recipients responsibility to ensure the electrical safety

before use. In the case of any equipment disposed of through the rubbish, the plug

must be cut off.

2.9PEOPLE

2.9.1 User

For the purposes of this document, the User is the person or group of people who

will make direct use of the equipment. In the case of a group, every member must

understand any limits or procedures imposed by the Risk Assessment or

Operational Procedures.

2.9.2 Electrical Safety Assessor

The Electrical Safety Assessor is required to assess the safety (or otherwise) of an

experimental rig as a whole. The Director of the Fluid Dynamics Laboratory will

appoint appropriate Assessors once he is satisfied of their competence to

undertake this task.

The Electronics Technician is an Electrical Safety Assessor.

3 Tests

This section outlines the various standard tests that may be performed on

electrical and electronic equipment. Additional tests for certain categories of

equipment are detailed under the documentation for that equipment.

3.1BRAND NEW EQUIPMENT

Brand new equipment must be tested or, if it carries the appropriate certification

(e.g. a CE mark), may be deemed safe based that certification, provided the levelof testing required for that certification is at lease comparable with the procedures


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laid out in this document. If the equipment is deemed safe based on the

manufacturers testing then the test sticker should be completed with New in

place of the date tested, and with an appropriate date entered for the date the next

test is due. All equipment processed in this manner must be logged and the record

sheet must indicate that no tests were undertaken.

3.2EQUIPMENT FROM OTHER SOURCES

Equipment that has been tested by another source (e.g. another department in the

University) should be inspected by someone authorised to undertake electrical

testing. If such equipment appears to be in good order and the tester is satisfied

that the test procedures the equipment has been subjected to previously are

adequate, then the equipment may be handled in a manner similar to that for brand

new equipment. The date for the next test should be calculated based on the

information contained on the existing sticker. If this produces a different date for

the next test than is indicated on the existing sticker, then the earlier of the two

dates must be selected. All equipment processed in this manner must be logged

and the record sheet must indicate that no tests were undertaken.

3.3STANDARD TESTS

3.3.1 Cable damage

Visual inspection.

Any cuts, abrasions, distortions or bad kinks in the cable, or damage to the

connectors, are to be rectified by replacing the cable. This work must be carried

out before proceeding with any of the other tests.

The integrity of the cable clamps should be confirmed at both ends of the cable.

Any fault or inadequacy found is to be rectified.

3.3.2 Casing damage and condition

Visual inspection.

Any damage to the equipment case should be mended and a risk assessment

undertaken on the adequacy of the repair. When the casing cannot be repaired to

an acceptable standard, the casing must be replaced or the equipment

decommissioned.

Ventilation slots, heat sinks and fans must be clear of obstruction.

Any build-up of dust or grease must be removed.

3.3.3 Fuse rating

Visual inspection.

The rating of the fuse in the plug must not exceed the rating of the associated

cable.

The type and rating of any user-replaceable fuse in the equipment must be in

accordance with the manufacturers specification.

3.3.4 Earth bond

If not double-insulated.


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actually submersed, and confirmation of earth terminals and routes to earth for

probes. Recommended supplementary tests for each category of equipment are

listed in 7.

4 Documentation

4.1RECORD SHEET

The test record sheet for every item should be completed. If an item fails, this

should be recorded, along with details of the cause of failure. Details of the

remedy should also be recorded.

Any item that deviates from the expected performance (e.g. the operational

current), must be noted along with the conditions under which the deviation was

found. Future tests should always include assessing whether this level of deviation

has changed.

When a record sheet is changed, it must be moved to the Updated folder. At

regular intervals, the details in this folder will be added to the database and thecorresponding sheets returned to the main folder.

If an item is disposed of, the record sheet should be removed from the main series

and transferred into the Decommissioned folder. The reason for

decommissioning should be recorded.

4.2TEST STICKER

Every item passing the test procedures should be marked with an appropriate test

sticker indicating the initials of the person responsible for the test, the date tested,

and the date the next test is due.

Cables and equipment must both have test stickers attached, unless the cable is anintegral (non-removable) part of the equipment. For the cable, the test sticker

should be located close to the mains plug. For the equipment, the test sticker

should be located in such a position that it is obvious to anyone attempting to

operate the equipment.

An item failing the test should be immediately removed from service and a

Failed Electrical Test Do Not Use notice attached to the plug and over the face

of the item.

4.3DATABASE

The database should reflect the contents of the Record Sheets and tie thisinformation in with the main equipment inventory, operation manuals and risk

assessments.

The database should be updated at regular intervals (at least quarterly) from the

Record Sheets contained in the Updated folder. Once the details contained by an

updated Record Sheet has been transferred to the database, the sheet should be

marked and returned to the main folder.

Once a quarter, the database should be used to generate a list of equipment for

which a test is over due, and a list of tests due in the coming quarter.


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5 Office Equipment

5.1OFFICE APPLIANCES

5.1.1 Desk lamps

Elements of risk assessmentLocation.Proximity to combustible material.Routing of cable.Test interval

Three years.Tests required

Standard tests.Switch.

5.1.2 Fans

Elements of risk assessment

Location.Routing of cable.Stability.Test interval


Standard tests.Finger guards.

5.1.3 Heaters


Location.Routing of cable.

Stability.Proximity to flammable materials.Test interval


Standard tests.Finger guards.Tilt switch.


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5.2KITCHE AND CLEANING

5.2.1 KettlesManual kettles are not permissible.


Location.Routing and length of cable.Stability.Proximity to flammable materials.Test interval


Standard tests.Automatic turn off.

5.2.2 MicrowavesManual kettles are not permissible.


Location.Routing and length of cable.Operator instructions.Suitable cooking implements.Cleanness.Test interval


Standard tests.Timer.

5.2.3 Vacuum cleaners

Elements of risk assessmentDry or wet and dry usage.Period of operation.Storage location.Dust filtering.Use with toner spillages.Test interval

One year.Tests requiredStandard tests.


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RCD plug (if wet and dry ability).5.3ITEQUIPMENT

5.3.1 Computers

Elements of risk assessmentLocation.

Ergonomics.

Routing of cables.Power and data.

Interchangeable power cables.These must be designated explicitly to the associated IT item and not

interchanged with any other cable. The 13A mains plug must be clearly

marked as to which item it belongs to. It is recommended that the IEC

connector is also marked. The cable must carry a test sticker and be re-tested

at the same time as the computer. If either the cable or the computer has a teststicker that is out of date, then both must be re-tested.

Test interval


Standard tests.Cable.Dust.

Fan operational.Obstruction of ventilation.Internal operational temperatures (where motherboard/BIOS provide these).

5.3.2 Computer monitors


Routing of cables.Adequacy of ventilation.Refresh rate and interference.Stability and crispness of picture.Ambient illumination.Ergonomics.Interchangeable power cables.

These must be designated explicitly to the associated IT item and not




at the same time as the monitor. If either the cable or the monitor has a test

sticker that is out of date, then both must be re-tested.


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Test interval


Standard tests.Obstruction of ventilation.

5.3.3 Laptops


Damage due to transportation.Especially of power cables and power supplies.

Connection to other standards.Any adapters should be tested.

Test interval

One year.Tests required

Standard tests.Cable.Adapter.

5.3.4 Printers


Adequacy of ventilation.

Toner spillage.Interchangeable power cables.

These must be designated explicitly to the associated IT item and not




at the same time as the printer. If either the cable or the printer has a test

sticker that is out of date, then both must be re-tested.

Test interval


Standard tests.Cable.Obstruction of ventilation.Filters.Internal dust and toner.

5.3.5 Data hubs


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Routing of cables.Test interval


Standard tests.5.4COMMUNICATION EQUIPMENT

5.4.1 Answerphones and dictation machines


Location.Ergonomics.

Routing of cables.

Test interval


Standard tests.5.4.2 Fax machines


Location.Ergonomics.

Routing of cables.Test interval


Standard tests.5.5REPRODUCTION EQUIPMENT

5.5.1 PhotocopiersThe testing of this equipment is part of the Service Contract for this equipment.


Adequacy of ventilation.Toner spillage.Test interval

As recommended in Service Contract.Tests required

As recommended in Service Contract.5.5.2 Binders


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Location.Test interval



5.6PROJECTION EQUIPMENT

5.6.1 Slide projectors


Routing of cables.Dazzle of lecturer.Test interval


Standard tests.Fan & ventilation slots.Procedure for replacing bulb.

5.6.2 Overhead projectors




Standard tests.

Fan & ventilation slots.Procedure for replacing bulb.

5.6.3 Data projectors



Three years.


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Availability of low-voltage alternative.Test interval

Three years if in Office.Two years if in Laboratory.Tests required

Standard tests.Switch.

7.1.2 Fans


Location.Stability.Test intervalThree years if in Office.Two years if in Laboratory.Tests required


7.1.3 Vacuum cleaners


Dry or wet and dry usage.Use in wet environment.Period of operation.Unattended operation.Test interval


Standard tests.RCD plug (wet and dry).

7.2LABORATORY APPLIANCES

7.2.1 Densitometer


Frequency of relocation.Test interval

Three years.Tests requiredStandard tests.


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Dust in heater/cooler unit.Leaks.

7.2.2 Refrigerator


Nature of contents.Location of electrics in event of leakage.Test interval


Standard tests.Dust on condenser & compressor.

Corrosion damage.Warning notices.

7.2.3 Freezer


Nature of contents.Use: storage or experiment.Risk of damage from experiments.Location of electrics in event of leakage.Test intervalTwo years.Tests required

Standard tests.Dust on condenser & compressor.Corrosion damage.Warning notices.Temperature within acceptable range.

7.3ITEQUIPMENT

7.3.1 Computers


Office or Laboratory location.Location relative to experiments.Risk of splashing.Connection to control or measurement circuits.Connection to data ports and other computer peripherals.


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Test interval


Standard tests.Dust.Fan operational.Obstruction of ventilation.Internal operational temperatures (where motherboard/BIOS provide these).

7.3.2 Computer monitors


Office or Laboratory location.Location relative to experiments.Risk of splashing.Adequacy of ventilation.Refresh rate and interference.Stability and crispness of picture.Ambient illumination.Ergonomics.Test interval



7.3.3 Printers


Office or Laboratory location.Risk of splashing.

Adequacy of ventilation.Test interval


Standard tests.Obstruction of ventilation.Filters.Internal dust and toner.

7.3.4 Data hubs


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Risk of splashing.Adequacy of ventilation.Stability and crispness of picture.Equipment stacks.

Video monitors are often positioned directly on top of VTRs. While thispractice is acceptable, it is not acceptable to subsequently position any further

equipment or items on top of the video monitor.

Test interval



7.4.3 Video timersElements of risk assessment

Location relative to experiments.Risk of splashing.Adequacy of ventilation.Test interval



7.4.4 High-speed cine camera


Location relative to experiments.Risk of splashing.Trip hazard from stand.Test interval


Standard tests.7.4.5 Video cameras

Most video cameras operate on a low voltage, using either batteries or an

external power supply. The present section deals only with those cameras

having a direct connection to the mains supply.


Location relative to experiments.Risk of splashing.


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Adequacy of mounting arrangements.Test interval

Two years.Tests required

Standard tests.7.4.6 Camera power supplies


Location relative to experiments.Risk of splashing or leaks.Risk of mechanical damage.Adequacy of physical attachment.

This is particularly relevant on turntables.

Test interval


Standard tests.Obstruction of ventilation.Damage to low voltage cable.

7.5LIGHT SOURCES

7.5.1 Projectors


Location relative to experiments.Risk of splashing or leaks.Risk of mechanical damage.Proximity to flammable materials.Adequacy of physical attachment.

This is particularly relevant on turntables, tripods and when light sources are

mounted in any orientation other than sitting on a bench.

Control of stray light.Even the relatively low intensities from a standard slide projector represent a

hazard, both directly to the eyes, and through dazzling laboratory users.

Measures must be taken to ensure no light causes a risk or inconvenience to

other Laboratory users.

Test interval


Standard tests.

Obstruction of ventilation.


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Operation of fan.Integrity of tripod plate or other mounting system.

7.5.2 Photographic lamps


Location relative to experiments.Risk of splashing or leaks.Risk of mechanical damage.Proximity to flammable materials.Risk to user of casing temperature.

These lamps run very hot. The case is fitted with a thermal cut-out to switch

the lamp off if the case temperature exceeds 150oC, but this temperature is still

sufficiently high to burn a user trapped against the lamp.

Adequacy of ventilation.These lamps should not have their fans or ventilation slots hindered in any

way.

Adequacy of physical attachment.Control of stray light.

The high intensities from these lamps represent a serious hazard, both directly

to the eyes, and through dazzling laboratory users. Measures must be taken to

ensure no light causes a risk or inconvenience to other Laboratory users. Non-

combustible materials must be used for any shielding closer to the lamp than

500mm. All shielding must be secured firmly and designed to prevent any

hindrance to the air flow through the lamp.

Can low voltage lamps or light sources in other locations be used instead?The typical location of these turntable lamps exposes the user to greater risk

than would be the case if the lighting was provided by low voltage lamps or

provided from a remotely mounted lamp.

Test interval


Standard tests.

Obstruction of ventilation.Case temperature.

7.5.3 Turntable lamps


Location relative to experiments.Risk of splashing or leaks.Risk of mechanical damage.Risk of injuring entangling user.

These lamps are intended for mounting on a turntable. As such, they willnormally be in motion relative to the user, introducing additional potential

hazards.


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Proximity to flammable materials.Adequacy of physical attachment.Control of stray light.

Even the relatively low intensities from a standard slide projector represent a

hazard, both directly to the eyes, and through dazzling laboratory users.

Measures must be taken to ensure no light causes a risk or inconvenience to

other Laboratory users.

Can low voltage lamps or light sources in other locations be used instead?The typical location of these turntable lamps exposes the user to greater risk

than would be the case if the lighting was provided by low voltage lamps or


Test interval


Standard tests.7.5.4 Fluorescent lamps


Location relative to experiments.Risk of splashing or leaks.Risk of mechanical damage.

The fluorescent tubes are particularly susceptible to breakage. Moreover, if

broken, they represent a greater hazard due to the cocktail of fluorescent

materials they contain.

Proximity to flammable materials.Fluorescent lamps run relatively cool and may safety be used much closer to

flammable materials than most other light sources. However, it is important

that adequate ventilation be maintained when doing so.

Adequacy of physical attachment.Can low voltage lamps or light sources in other locations be used instead?

It is sometimes necessary to locate these lamps below an experimental

apparatus, thus exposing the lamps to a significantly increased risk from leaks

and splashes. The possibility of using low voltage lamps or other remote

sources of light should be considered.

Test interval


Standard tests.Diffusers and end caps.

The diffuser and end caps provide part of the protection to the tube and

electrics within the lamp. The diffuser and end caps, or a suitable alternative

arrangement, must be secure and intact.

Temperature.


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The operational temperature, when the lamp has been left on for a number of

hours, should be checked if air flow around the lamp is hindered in any way.

7.5.5 Light boxes


Location relative to experiments.Risk of splashing or leaks.Risk of mechanical damage.Test interval

Two years.

Tests required

Standard tests

7.5.6 Arc lampsThe xenon arc lamps consist of a separate power supply and lamp unit. The

power supply generates both very high voltages (30kV) for striking the arc,

and high currents (at relatively low voltages) for maintaining the arc. For

most of the units, the power supply and lamp unit are permanently wired

together, but for one it is possible to disconnect the two.


Location relative to experiments.The relatively short length of the cables connecting the lamp unit to the power

supply can cause difficulty. It is important to ensure that this cable is not put

under any significant strain, and that both the lamp and the power supply aremounted in a secure fashion in a safe location.

Risk of splashing or leaks.These lamps use very high voltages (30kV) to strike the ark. Any splashes or

moisture may lead to the user being exposed to these voltages.

Risk of mechanical damage.The cables and terminals connecting the lamps and power supplies are

particularly vulnerable. Due to the high voltages associated with striking the

ark, it is extremely important that the insulation remains intact.

Proximity to flammable materials.The collimated or focused light produced by the arc lamps is potentiallyextremely hot and capable of igniting most flammable materials if placed

within 500mm of the lamp. The use of a cold mirror or cold window to filter

the heat from the light reaching an experiment is strongly recommended.

Adequacy of ventilation.These lamps and their power supplies must not have their fans or ventilation

slots hindered in any way.

Adequacy of physical attachment.Both the power supply and lamp unit need to be attached securely.

Control of stray light.The high intensities from these lamps represent a serious hazard, both directlyto the eyes, and through dazzling laboratory users. Measures must be taken to


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ensure no light causes a risk or inconvenience to other Laboratory users. Non-

combustible materials must be used for any shielding closer to the lamp than

500mm. All shielding must be secured firmly and designed to prevent any

hindrance to the air flow through the lamp.

Can low voltage lamps or light sources in other locations be used instead?The typical location of these turntable lamps exposes the user to greater riskthan would be the case if the lighting was provided by low voltage lamps or


Test interval

One year.This short test interval is required due to the presence of the high voltages

associated with striking the arc.

Tests required

Standard tests.Obstruction of ventilation of power supply.Obstruction of ventilation of lamp.Check cable to lamp.Check and clean cable terminals/connectors.

7.5.7 Strobe lights


Location relative to experiments.Risk of splashing or leaks.Risk of mechanical damage.Adequacy of physical attachment.Control of stray light.

The high intensities from these lamps represent a serious hazard, both directly

to the eyes, and through dazzling laboratory users. Measures must be taken to

ensure no light causes a risk or inconvenience to other Laboratory users.

Test interval

Two years.Tests requiredStandard tests.

7.6LASERS

Not currently in use. Secured under lock and key.

7.7POWER SUPPLIES

7.7.1 Bench supplies


Location relative to experiments.Risk of splashing or leaks.


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It is often possible and desirable to locate the power supplies well clear of the

experiment, bringing only low-voltage connections through to the experiment.

Adequacy of ventilation.Adequacy of physical attachment.

When the supply is integrated into an experimental rig such as a rotating table,

it is essential that it is firmly attached.

Low-voltage route to earth.Under most circumstances the low voltage side of the power supply should be

earth-referenced. This will ensure that, in the event of power supply failure,

the equipment will remain safe. This earth referencing is most conveniently

achieved at the power supply itself; often power supplies have an earth

terminal and a removable strap between this and either the positive or

negative side. If connection to earth is not possible or not desirable (e.g. to

avoid earth loops), then an earth point should still be provided somewhere in

the equipment.

Test interval


Standard tests.Obstruction of ventilation.Earth terminal.

7.7.2 Plug-in adapters

Elements of risk assessmentLocation relative to experiments.Risk of splashing or leaks.

It is often possible and desirable to locate the power supplies well clear of the

experiment, bringing only low-voltage connections through to the experiment.

Adequacy of ventilation.Free movement of air around the adapter must be maintained. As most

adapters have internal temperature fuses, failure to observe this is likely to

lead to the adapter ceasing to function. Note that under normal circumstances

the Laboratory will not attempt to repair any plug-in adapters following

failure of this fuse.

Test interval


Standard tests.Low voltage cable insulation.

7.7.3 High voltage suppliesThis category of equipment is for power supplies generating voltages in excess

of mains voltages. Where at all possible, alternative solutions not requiringsuch voltages should be employed.


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Location relative to experiments.The presence of high voltages, the generation of interference and the need to

keep cables relatively short complicate the location of high voltage supplies. It

is critical that the high voltage cables are not put under strain and do not run

through an area where they are likely to suffer damage or be exposed to

electrolytes.

Risk of splashing or leaks.Any splashes or moisture may lead to the user being exposed to these voltages.

Risk of mechanical damage.The high voltage cables are especially sensitive and prone to damage. Where

these cables must be exposed, they should be provided with some for of

covering or armouring. The cables and terminals connecting the lamps and

power supplies are particularly vulnerable. Due to the high voltages

associated with striking the ark, it is extremely important that the insulation

remains intact.

Adequacy of physical attachment.The power supply, cables and any associated equipment need to be attached

securely.

Can low voltage equipment be used instead?Where possible, low voltage equipment should be used instead. Where only

high-voltage equipment is feasible, the reasons behind this must be given

explicitly in the Risk Assessment.

Test interval


Standard tests.Check HV insulation.

7.8LABORATORY INSTRUMENTATION

7.8.1 Amplifiers


Location relative to experiments.Risk of splashing or leaks.Adequacy of physical attachment.Earth for probes.

Probe casings should normally be earthed. If this is not possible, or not

desirable (e.g. due to the formation of earth loops), a separate earth

electrode must be incorporated into the design of the apparatus.

Risk to/from attached equipment.What risks might the user be exposed to if any attached equipment fails? Does

failure of this equipment have other vectors with potential risk (e.g. probes).

Test intervalTwo years.


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Tests required

Standard tests.Input/output isolation.

7.8.2 Bridge circuits


Location relative to experiments.Risk of splashing or leaks.Adequacy of physical attachment.Earth for probes.

Probe casings should normally be earthed. If this is not possible, or not

desirable (e.g. due to the formation of earth loops), a separate earth

electrode must be incorporated into the design of the apparatus.

Risk to/from attached equipment.What risks might the user be exposed to if any attached equipment fails? Does

failure of this equipment have other vectors with potential risk (e.g. probes).

Test interval


Standard tests.Probe isolation.

7.8.3 MultimetersBattery-powered multimeters should also be tested.


Location relative to experiments.Risk of splashing or leaks.Adequacy of physical attachment.Probe insulation.

This must be adequate to withstand the maximum voltage present on the

experimental rig, not just the voltage that is to be measured.

Test intervalTwo years.Tests required


7.8.4 Oscilloscopes


Location relative to experiments.By use of probe cables of a suitable length, the location of the oscilloscopeneed not be close to the experiment.


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Risk of splashing or leaks.Adequacy of physical attachment.Probe insulation.

This must be adequate to withstand the maximum voltage present on the

experimental rig, not just the voltage that is to be measured.

Test interval



7.8.5 High voltage equipmentThis category of equipment is for equipment utilising voltages in excess of

mains voltages. Where at all possible, alternative solutions not requiring such

voltages should be employed.


Location relative to experiments.The presence of high voltages, the generation of interference and the need to

keep cables relatively short complicate the location of high voltage supplies. It

is critical that the high voltage cables are not put under strain and do not run

through an area where they are likely to suffer damage or be exposed to

electrolytes.

Risk of splashing or leaks.Any splashes or moisture may lead to the user being exposed to these voltages.This will occur at much lower levels of contamination than for standard

voltage equipment.

Risk of mechanical damage.The high voltage cables are especially sensitive and prone to damage. Where

these cables must be exposed, they should be provided with some for of

covering or armouring. The cables and terminals connecting the lamps and

power supplies are particularly vulnerable. Due to the high voltages

associated with striking the ark, it is extremely important that the insulation

remains intact.

Adequacy of physical attachment.The power supply, cables and any associated equipment need to be attached

securely.

Can low voltage equipment be used instead?Where possible, low voltage equipment should be used instead. Where only

high-voltage equipment is feasible, the reasons behind this must be given

explicitly in the Risk Assessment.

Test interval

One year.Tests requiredStandard tests.


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Check HV insulation.7.9MOTORS AND CONTROLLERS

7.9.1 Servo motor controllers

Elements of risk assessmentLocation relative to experiments.Risk of splashing or leaks.Adequacy of physical attachment.Earth-referencing.

Should the motor be earth referenced, or is it safer to have it floating? Earth-

referencing in combination with a suitable fuse, circuit breaker or RCD may

reduce the risk associated with higher voltage servo motors.

Test interval


Standard tests.Output isolation.

7.9.2 Servo motors


Location relative to experiments.Risk of splashing or leaks.Adequacy of physical attachment.Risk of entanglement or injury.

Are guards required? Have all sharp corners been removed?

Earth-referencing.Should the motor be earth referenced, or is it safer to have it floating? Earth-

referencing in combination with a suitable fuse, circuit breaker or RCD may

reduce the risk associated with higher voltage servo motors.

Test interval


Standard tests.Output isolation.

7.9.3 AC motors


Location relative to experiments.Risk of splashing or leaks.

Adequacy of physical attachment.Risk of entanglement or injury.


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Are guards required? Have all sharp corners been removed?

Low voltage alternatives.Is it possible to use a low voltage motor instead?

Test interval


Standard tests.7.10PUMPS

7.10.1 Integrated pumps


Location within experimental rig.

Risk of splashing or leaks.What additional risks will occur if the pump leaks risks both due to the pump,

and due to anything that may be contaminated as the result of the pump

leaking?

Adequacy of physical attachment.Cable routing.

Does this take the best route available? Is it protected from mechanical

damage? Is it possible to inspect the cable for damage?

Switching and control.How is the pump to be controlled? Can it be shut off safely in the result of a

leak or a detached hose?Guards.

Some integrated pumps are not self-contained units. In such cases, the

question of whether guards are necessary should be addressed.

Test interval


Standard tests.Check for leaks.

7.10.2 Peristaltic pumps


Location relative to experimental rig.Risk of splashing or leaks.

What additional risks will occur if the pump leaks risks both due to the pump,

and due to anything that may be contaminated as the result of the pump

leaking?

Adequacy of physical attachment.Test intervalTwo years.


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Tests required

Standard tests.Check for leaks.

7.10.3 Submersible pumps


Location within experimental rig.Adequacy of physical attachment.Route to earth.

If the pump or cable insulation fails, the water may become live. It is desirable

that a suitable route to earth must always be is provided, either through earth-

bonding of metal parts of the apparatus exposed to the water, or by the

provision of an additional earth electrode of at least 200mm2

area, as outlined

in 2.7.6of the standard procedures.

RCD on mains cable.The mains cable of the submersible pump should normally be fitted with an

RCD plug, even if this will be plugged into circuits with other RCD protection.

Test interval

One year.

Tests required

Standard tests.Optional: check insulation and/or leakage current when submerged.RCD required.

7.10.4 Vacuum pumps


Location relative to experimental rig.Risk of splashing or leaks.Adequacy of physical attachment.Test interval


Standard tests.7.10.5 Double-bucket pumps


Route to earth. All metal work on the double buckets must be earth-bonded via the earth

provided on the pump.

RCD on mains cable.The mains cable of the submersible pump should normally be fitted with an



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Emergency shut-off.Are the provisions for stopping the turntable in an emergency adequate? Will

this also cut the power to the mains sockets?

Maximum speed.Is there a limit on the maximum speed of the turntable? Is this limit safe? Who

has the ability to change or over-ride this limit? What will happen if this limitis exceeded?

Test interval


Standard tests.RCD required.Shut-off switch.Speed limiter.

Verify that turntable cannot be rotated faster than the maximum allowable

speed.

7.12LABORATORY EQUIPMENT

7.12.1 Heat baths



What additional risks will occur if the bath or associated tubing leaks risksboth due to the bath, and due to anything that may be contaminated as the

result of the bath leaking?

Temperature control.What is the effect of the temperature control circuit failing (or user error),

resulting in temperatures either much higher or much lower than intended?

Test interval


Standard tests.Check for leaks.Check earth leakage current when full.

7.12.2 Stirrers



What additional risks will occur if the bath or associated tubing leaks risks

both due to the bath, and due to anything that may be contaminated as the

result of the bath leaking?


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Test interval


Standard tests.7.12.3 Scales


Location.Contamination by chemicals.Test interval


Standard tests.7.12.4 Immersion heaters


Location within experimental rig.Risk of drying out.

What will happen if the heater does not remain immersed?

Route to earth. If the insulation fails, the water may become live. A suitable route to earth

must always be provided. In most cases this will be through the metal case of

the immersion heater. If this route is not possible, the route to earth may eitherbe through earth-bonding of metal parts of the apparatus exposed to the water,

or through the provision of an additional earth electrode of at least 200mm2

area, as outlined in 2.7.6of the standard procedures.

RCD on mains cable.The mains cable of the immersion heater should normally be fitted with an


Test interval

Two years.Tests requiredStandard tests.Check for leaks.Check leakage current when immersed.RCD required.

7.13FRAMEWORKS AND TANKS

7.13.1 Metalwork


Live metalwork.


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The metalwork of tanks may become live due to the failure of equipment, the

incorrect connection of equipment, or as a result of stray electromagnetic

fields. To prevent this happening, all metalwork must be connected to earth as

described by the wiring regulations BS7671.

A conductor with cross-section not less than 6mm2

must connect all fixedframes to a suitable earth. Water supply pipe work may be used as the earth

only once its continuity to earth has been adequately verified to have a

resistance of less than 0.1.

Moveable frameworks and tanks must be provided with a suitable earth

terminal and lead. This earth lead must be connected to a suitable earth

whenever the framework or tank is used in conjunction with any electrical

equipment. It is recommended that the connection be made through the same

RCD-protected circuit as the electrical equipment used with the framework or

tank. This connection may be through a dedicated earth terminal on the

electrical equipment, or using an adapted earth-only mains plug inserted intoa socket.

Each electrically separate but mechanically integrated part of the metalwork

must be connected with an earth strap of at least 2.5mm2

cross-section (4mm2

if not sheathed or mechanically protected). This earth strap may be omitted

only when a reliable earth with a resistance of less than 0.1 is formed as an

inherent part of the design of the framework or tank.

Test interval


Test earth bonding of all exposed metal work on frames and tanks.7.14POWER CORDS

7.14.1 Standard cords (IEC)


Routing.Trip hazard.Location.

In Office or Laboratory?

Use.For computer or laboratory equipment?

Test interval


Visual inspection.

Earth continuity.Fuse.


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7.14.2 Non-standard cords




Use.For computer or laboratory equipment?

Test interval


Visual inspection.Earth continuity.Fuse.

7.14.3 Cords with RCD




Use.For computer or laboratory equipment?Test interval


Visual inspection.Earth continuity.Fuse.RCD.

7.15PLUG-BOARDS AND EXTENSION LEADS

7.15.1 Plug-boardsPlug-boards that are not integrated permanently into an experimental set-up.


Location relative to experimental rig.Risk of splashing or le

electrical testing procedures

Documents