BUREAU OF INDIAN STANDARDS

Manak Bhavan, 9 Bahadur Shah Zafar Marg New Delhi 110002

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15/-101, -102 13-08-2015 : 15 .................................................................................................................................

: 1. 15 2. 3.

,

- : 1. : 15 6897 3 2. : 15 6898 31

: 15-10-2015 , ,

()

:

BUREAU OF INDIAN STANDARDS

Manak Bhavan, 9 Bahadur Shah Zafar Marg New Delhi 110002

Phones 2323 0131 TeleFax +91 11 2323 1192 Website : www.bis.org.in

2323 3375 Extn 4284 email : eetd@bis.org.in

DRAFTS IN WIDE

CIRCULATION

Document Despatch Advice

TECHNICAL COMMITTEE ETD 15

------------------------------------------------------------------------------------------------------------------------------- ADDRESSED TO:

1 All Members of Rotating Machinery Sectional Committee, ET 15; 2. All Members of Electrotechnical Division Council; and

3. All other Interested.

Dear Sir(s),

Please find enclosed a copy of the following draft Indian Standard:

DOC NO. TITLE

ET 15 (6897) Rotating Electrical Machines Specification for Terminal Boxes for 3 Phase Rotating Electrical Machines

ET 15 (6898) Rotating Electrical Machines Part 31 : Selection of energy-efficient motors including variable speed applications Application guide (IEC 60034-31:2010)

Kindly examine the draft standard and forward your views stating any difficulties which you are likely to

experience in your business or profession, if these are finally adopted as Indian Standards. In case, you

need a copy of the document, kindly send us your mailing address.

Comments, if any, may please be made in the format given overleaf and mailed to the undersigned.

Last date for comments: 15-10-2015.

In case no comments are received or comments received are of editorial nature, you will kindly permit us

to presume your approval for the above document as finalized. However, in case of comments of

technical in nature are received then it may be finalized either in consultation with the Chairman,

Sectional Committee or referred to the Sectional Committee for further necessary action, if so desired by

the Chairman, Sectional Committee.

Thanking you,

Yours faithfully

(D Goswami)

Sc F & Head (Electrotechnical)

Email: eetd@bis.org.in

Encl: As above

REFERENCE DATE

ETD 15/ T- 101, T-102 13-08-2015

mailto:eetd@bis.org.in

Date Document No.

13-08-2015 ET 15 (6897) , ET 15 (6898)

Sl.

No.

Name of the

Organization

Clause/

Sub-clause

Paragraph/

Figure/Table

Type of

Comment

(General/

Technical/

Editorial

Comments Proposed Change

Doc: ET 15(6897)

BUREAU OF INDIAN STANDARDS

DRAFT FOR COMMENTS ONLY

(Not to be reproduced without the permission of BIS or used as Indian Standard)

Draft Indian Standard

ROTATING ELECTRICAL MACHINES: SPECIFICATION FOR

TERMINAL BOXES FOR 3 PHASE ROTATING ELECTRICAL MACHINES

Last date for receipt of comments is 15-10-2015

________________________________________________________________

0 Foreword

(Formal clauses will be added later)

1 SCOPE

This standard specifies types and performance requirements for terminal box for 3 phase

rotating electrical machines for rated voltages up to 15 kV rms.

This standard also specifies requirements of the terminations of the machines to

withstand high energy fault. However, it is to be noted that, withstand high energy fault is not a standard feature of the terminal box of machines with rated voltage up to and

including 690 volts. In such case, the design of terminal box will be entirely different and

may be inappropriate to the size of the machine itself.

For machines with rated voltages up to and including 690 volts, it is assumed that, fuses

or other energy limiting devices would protect the machine.

The standard applies to terminal boxes and terminal enclosures, but it does not specify

the requirements for flameproof terminal enclosures.

The choice of a particular termination will be largely governed by the service and

environmental conditions, but the standard is also relevant to the various types of cables

normally used, including aluminium and, where applicable, cable spreader boxes. The

scope of this standard does not cover the external supply cables in detail, but insofar as

the design of the terminals is concerned, essential data is listed.

Terminal boxes for small rating machines having rated outputs up to and including 0.75

kW or kVA per 1000 r/min are not covered by this standard.

1

2 REFERENCES

The following referenced documents are indispensable for the application of this

document. For dated references, only the edition cited applies. For undated references,

the latest edition of the referenced document (including any amendments) applies.

.

BS:4999:part145:1997 Specification of winding terminations

BS 5372:1997 Dimensions of cable terminations for multi core extruded solid dielectric

insulated distribution cables of rated voltages 600/1000 and 1900/3300V having copper

or aluminium conductor.

.

CEGB standard 44122 Issue 2 Sept. 1969

ESI Standard 44-3 ; Issue 1 January 1975

3 TERMS AND DEFINITIONS

For the purposes of this document, the definitions in IEC 60050 and the following

definitions apply.

For the purposes of this standard, the term agreement means agreement between the manufacturer and purchaser.

3.1 Type Test

A test of one or more machines made to a certain design to show that the design meets

certain specifications. [IEV 411-53-01]

NOTE The type test may also be considered valid if it is made on a machine, which has minor deviations of rating or other characteristics. These deviations should be subject to agreement.

3.2 Routine Test

A test to which each individual machine is subjected during or after manufacture to

ascertain whether it complies with certain criteria. [IEV 411-53-02]

3.3 Degree of Protection

As defined in IEC 60034-5: 2000, 3.

3.4 Short Circuit

The accidental or intentional connection, by a relatively low resistance or impedance, of

two or more points in a circuit which are normally at different voltages.

2

3.5 Short Circuit Current

An over- current resulting from a short circuit due to a fault or an incorrect connection in

an electric circuit (IEV 441-11-07).

NOTE The Short Circuit current levels defined in this standard is due to short circuits at the line terminals inside the terminal box.

3.6 Gland Plate

The plate provided at the bottom of terminal box facilitating cable entry to the motor

from either top, bottom or side.

3.7 Low Voltage

From 200V up to 1000V

3.8 High Voltage

Above 1000V up to 12000 V

3.9 Termination

The arrangement provided for making the connections between the machine winding

leads and the external conductors.

3.10 Terminal

A conducting element of a winding intended for connection to an external electrical

conductor.

3.11 Stud Terminals

A form of termination in which the terminals are stud mounted integral with the machine

frame or in a separate terminal enclosure.

3.12 Strip terminals

A form of termination in which the terminals are strip mounted integral with the machine

frame or assembly.

3.13 Flexible Leads

A form of termination in which the ends of the machine winding are brought out as

unsupported insulated flexible conductors.

3

3.14 Air Insulated Termination

A termination so designed that the protection of phase conductors against electrical

failure is by adequately spaced bare conductors with appropriate insulated supports.

3.15 Cable Coupler

A form of termination in which the terminals are connected to the supply leads by means

of a plug and socket device.

3.16 Separable Insulated Connectors

A form of termination comprising a molded bushing and insulated elbow connector

coupling.

3.17 Separate Terminal Enclosure

A form of termination in which the terminals are connected to the incoming supply leads

inside a chamber, which need not be fully enclosed and may be formed by the

foundations beneath the machine.

3.18 Terminal Box

A type of terminal enclosure in which the terminals are connected to the incoming supply

leads inside a box. which encloses the connections and is of a size consistent to suit the

Rated r.m.s. current with adequate access and with adequate clearances and creepage

distances suitable for the highest system Voltage requirements.

3.19 Pressure Relief Terminal Box

A terminal box such that internal fault energy is relieved through a pressure relief

diaphragm without any disintegration of the front side exposed to operating Personnel.

3.20 Pressure Containing terminal Box

A terminal box such that the Internal fault energy is withstood without any disintegration

from Outside surface.

3.21 Flameproof Terminal Box

A terminal box designed to comply with additional flameproof requirements of

IEC60079-1.

3.22 Increased Safety Terminal Box

A terminal box designed to comply with additional Increased Safety requirements of IEC

60079-7.

3.23 Air Insulated Terminal Box

A terminal box so designed that the protection of phase conductors against electrical

fault within the terminal box is ensured by adequate air gap, with or without appropriate

insulated supports.

4

3.24 Phase Insulated Terminal Box

A terminal box so designed that the protection of phase conductors against electrical

failure within the terminal box is separated mainly by solid insulation.

3.25 Phase Separated Terminal Box

A terminal box so designed that phase separation is provided by earthed metal barriers so

as to restrict any electrical breakdown between phases.

3.26 Phase Segregated Terminal Box

A terminal box so designed that phase segregation is provided by Insulated barriers so as

to restrict any electrical break- down between phases and / or phase to earth

4 SERVICE CONDITIONS

The Terminal Box shall be designed to suit operating site conditions specified for rotating

electrical machine, unless otherwise specified by the purchaser:

5 MATERIAL FOR CONSTRUCTION

5.1 Low Voltage Machines

Terminal box shall generally be of metal and adequately sized to terminate either copper

or aluminum conductor cables. The motor manufacturer shall ensure the type of cable

envisaged (copper or aluminium) prior to manufacturing of the terminal box. In other

than hazardous locations, non metallic, non burning materials for terminal boxes may be

used provided internal grounding means between the machine frame and the equipment

grounding connection is incorporated into the terminal box.

However, these terminal boxes shall meet the requirements of short circuit test as per

table-5.

In case cable end boxes are provided, the same may be of steel or cast iron; for single

core cables the cable end plate shall be of non magnetic material.

5.2 High Voltage Machines

Terminal box shall be of metal and adequately sized to terminate either copper or

aluminum conductor cables. The motor manufacturer shall ensure the type of cable

envisaged (copper or aluminium) prior to manufacturing of the terminal box.

In case cable end boxes are provided, the same may be of steel or cast iron; for single

core cables the cable end plate shall be of non magnetic material.

6 ARRANGEMENTS AND ENCLOSURES

5

Terminal box shall have a degree of Protection as per clause 13 such that it remains clean

and dry internally in service. The arrangements shall embody the relevant features

selected from table 1. The Pressure relief device/ diaphragm should be so located that any

relief from it should not get dissipated away from the Motor or relief should be toward

the motor on which it is mounted.

Table 1 (Clauses 6 and 11)

Combinations for termination assembly

Sl No.

(1)

Terminal

Arrangement

(2)

Terminal

Type

(3)

Type of Energy Dissipation in

Case of the Terminal Box for

High Fault Levels V>=1100,

MVA>=value in table 5

(4)

i)

ii)

iii)

iv)

v)

Air insulated

Phase insulated

Phase separated

Phase segregated

Separate terminal

Enclosure

Stud

Bushing

Strip

Cable coupler

Flexible leads

Pressure containing

Terminal box

or

Pressure relief Terminal box

NOTE The combination is to consist of any one of the termination arrangements given in column 1 combined with any one of the conducting parts given in column 2, combined with, for high fault levels, either of the terminal boxes given in

column 3.

7 DIMENSIONS OF CABLE TERMINATION

Fig 1

6

7.1 Cable Sizes

The terminal box shall be suitable to accommodate the size and number of cables as

agreed between manufacturer and purchaser.

LV motor terminal box shall have gland plates suitable to terminate cables according to

table-2. This table is only for guidance purpose.

Table 2

(Clauses7.1 and 8) Dimensions of Cable Terminations for 3 and 4 Core Extruded Solid Dielectric Insulated

Distribution Cables of Rated Voltages 600/1100 volts and 3 core Cables of Rated

Voltages, 1900/3300 volts having Copper or Aluminium Conductors

Sl No. Dimensions and Current rating of Cable Terminations for 600/1000 V

Cross Section

Area of

Cable

Conductor

mm

(1) (2)

Aluminum Cable Copper Cable Minimum

Earthing

Terminal

size inside

terminal

box

(11)

B

(Minimum)

(3)

F

(4)

H

(5)

Current

Rating (In

ground)

with

Deration

Factor of

0.65 (6)

B

(Minimum)

(7)

F

(8)

H

(9)

Current

Rating (In

ground)

with

Deration

Factor of

0.65 (10)

i) 10 120 6 4.2 / 6.4 37 90 6 4.2 / 6.4 46 M5

ii) 16 125 6 6.4 / 8.2 47 100 6 6.4 / 8.2 60 M5

iii) 25 130 10 6.4 / 8.2 61 125 10 6.4 / 8.2 77 M5

iv) 35 145 10 6.4 / 8.2 73 140 10 6.4 / 8.2 93 M5

v) 50 165 10 8.2 / 10.2 86 165 10 8.2 / 10.2 113 M5

vi) 70 190 10 8.2 / 10.2 106 200 10 8.2 / 10.2 136 M8

vii) 95 220 10 10.2 / 12.7 127 225 10 10.2 / 12.7 164 M8

viii) 120 225 10 10.2 / 12.7 145 245 10 10.2 / 12.7 187 M8

ix) 50 240 10 10.2 / 12.7 162 270 10 10.2 / 12.7 210 M8

x) 185 265 10 10.2 / 12.7 183 300 10 10.2 / 12.7 234 M10

xi) 240 290 10 12.7 / 16.2 212 330 10 12.7 / 16.2 269 M10

xii) 300 360 10 16.2 / 20.3 238 375 10 16.2 / 20.3 300 M10

xiii) 400 480 10 16.2 / 20.3 271 500 10 16.2 / 20.3 331 M12

xiv) 2x185 300 10 10.2 / 12.7 366 340 10 10.2 / 12.7 468 M10

xv) 3x185 335 10 10.2 / 12.7 549 380 10 10.2 / 12.7 702 M10

xvi) 4x185 370 10 10.2 / 12.7 732 420 10 10.2 / 12.7 936 M10

xvii) 2x240 355 10 12.7 / 16.2 424 400 10 12.7 / 16.2 538 M10

xviii) 3x240 420 10 12.7 / 16.2 636 480 10 12.7 / 16.2 807 M10

xix) 4x240 480 10 12.7 / 16.2 848 545 10 12.7 / 16.2 1076 M10

xx) 2x300 440 10 16.2 / 20.3 476 460 10 16.2 / 20.3 600 M10

7

NOTES

1 The current rating of the cable is based upon a deration factor of 0.65

2 For HT motors the distance between gland plate and the terminal studs shall not be less than 500 mm.

7.2 Factors, which Affects Cable Accommodation

The limitations imposed by a number of factors as detailed in a, b, c have been taken into

account in determining the length required in the terminal enclosure to accommodate the

cable cores (dimension B in Fig.1).

a) Terminal lugs: Terminal lugs of compression type are usually longer than those of

other types.

b) Layout of cable cores: The dimensions specified in above table allow for the cores to

be crossed within the enclosure. However, if the terminal enclosure allows for the entry

of two or more cables, it will be necessary to increase dimension B to allow for crossing a

greater number of cable cores.

c) Type of terminal box; Phase segregation or phase separated.

8 EARTHING IN TERMINAL BOX

When motors are provided with terminal box for fixed terminal connections, a means for

earthing of terminal box shall be provided inside or outside the terminal box. A screw

stud or bolt intended for the termination of earthing conductor shall not be smaller than

mentioned in Table 2. When a terminal box mounting screw stud or bolt is used to secure

the earthing conductor to the main terminal box, there shall be at least one other

equivalent securing means for fixing the terminal box to the machine frame.

NOTE Use of.3 core cables is recommended for effective earthing of terminal box.

9 ELECTRICAL CLEARANCES

With the components of the terminations in the correct position, the clearances .and

creepage distances shall be not less than the values given in Table 3 and 4 as applicable.

Further, the clearances provided shall be adequate between cable lugs (that is equal to or

higher than the value indicated in table below) at termination to ensure ease of Copper or

Aluminium cable installation. Table 3

(Clause 9)

Minimum Clearance Distances (mm) in Air between Phase to Earth or between Phases

Sl No.

(1)

Nominal

Voltage

(2)

Machines with Frame Sizes

Up to 160 180,200

and 225

250 and 280 315

Rating of Machine at Nominal Voltage

Up to 22 kW

(3)

Above 22 kW

Up to 75 kW (4)

Above 75kW

Up to 185 kW (5)

Above

185 kW (6)

xxi) 3x300 520 10 16.2 / 20.3 714 540 10 16.2 / 20.3 600 M10

xxii) 4x300 600 10 16.2 / 20.3 952 625 10 16.2 / 20.3 600 M10

xxiii) 2x400 600 10 16.2 / 20.3 542 615 10 16.2 / 20.3 600 M12

xxiv) 3x400 600 10 16.2 / 20.3 813 720 10 16.2 / 20.3 600 M12

xxv) 4x400 600 10 16.2 / 20.3 1084 720 10 16.2 / 20.3 600 M12

8

i)

ii)

iii)

iv)

v)

vi)

vii)

viii)

ix)

Upto 660

1100

2300

3300

4160

6600

11000

13800

15000

6.4

-

-

-

-

-

-

-

-

8.0

-

-

-

-

-

-

-

-

10.0

12.5

-

-

-

-

-

-

-

12.5

19.0

30.0

37.5

45.0

63.0

75.0

85.0

95.0

Table 4

(Clause 9)

Minimum Creepage Distances (mm) between Phase to Earth or between Phases

Sl No.

(1)

Nominal

Voltage

(2)

Machines with Frame Sizes

Up to 160 180,200

and 225

250 and 280 315

Rating of other Machine at Nominal Voltage

Up to 22

kW

(3)

Above 22

kW Up to 75

kW (4)

Above 75kW

Up to 185

kW

(5)

Above 185

kW

(6)

i)

ii)

iii)

iv)

v)

vi)

vii)

viii)

ix)

Upto 660

1100

2300

3300

4160

6600

11000

13800

15000

11.2

-

-

-

-

-

-

-

-

12.5

-

-

-

-

-

-

-

-

12.5

19

-

-

-

-

-

-

-

19

25

40

50

60

90

125

140

150 NOTES:

1. Some designs of pressure containing type terminal boxes may require the use of clearance and creepage distances

smaller than the values given in tables 3,. and 4.

2. The values given are for air insulated terminal boxes. These can be considerably less for phase separated and phase

insulated terminal boxes.

3. For Phase segregated terminal boxes the clearance and creepage values are left to the manufacturers design, except that these will have to pass the tests given in sec. 15 (b)

10 POSITION OF TERMINAL BOX

For foot-mounted machines of frame size 56 to 315, the following shall apply:

10.1 The terminal box shall be so located on the right-hand side, when looking at the

driving end of the motor, that there is adequate clearance between cable end plate and

ground for ease of routing and termination of cables;

10.2 It is recommended that unless the terminal box is on the top, the motors shall be so

9

constructed that the terminal box may be located on the left-hand side by the

manufacturer, if requested by the user at the time the motor is ordered.

NOTES

1. Provision should preferably be made so as to enable cable entry to the terminal box in any one of four directions at right

angles.

2. The terminal box should be separated from main stator frame through a suitable barrier plate / or similar arrangement, so

as to prevent any foreign particles/objects falling inside the stator.

11 ABILITY OF TERMINATIONS FOR MACHINES RATED AT 1100V AND

ABOVE TO WITHSTAND SYSTEM FAULTS

Machine primary winding terminations, including internal flexible cables and connection

cables between the power supply cables and the motor windings, of machines for use on

electrical systems having nominal short circuit MVA capacities equal to or greater than

those in Table 1 shall be so rated that they will safely carry the fault current for the

specified duration.

NOTE The fault clearance time is usually assumed to be not longer than 0.25 s for machines protected by circuit breakers.

Table 5 (Clauses 5.1 and 11)

Nominal Short-circuit Capacity

Sl No.

(1)

Operating Voltage

(2)

Fault Level

(MVA)

(3)

Time Duration for

Withstanding

(4)

i) 11kV 2250 0.25 SEC

ii) 6.6kV to 11 KV 750 0.25 SEC

iii) >3.3kV to 6.6 KV 500 0.25 SEC

iv) 690V to 3.3 KV 250 0.25 SEC

v) Up to 690V 35 0.25 SEC

Terminal boxes for machines protected by circuit breakers and having nominal short

circuit capacities equal to or higher than those in table 5 shall be of either the pressure

relief or pressure containing type.

NOTE All motors upto and including 75kW/90kW shall be deemed to have fuse protection. Where motors are with only MCB and there is no fuse wire in circuit, then the terminal box shall be made suitable for with standing a short circuit

capacity of 35MVA for 0.25 secs

12 DEGREE OF PROTECTION

The degree of protection for terminal boxes shall minimum be that for its motor.

However degree of protection of IP54 and above may be considered for user specific

requirements.

13 TERMINATION FOR MOTOR AUXILIARIES

10

The termination for motor auxiliaries shall be provided in a separate auxiliary terminal

box or inside the main terminal box as agreed between the manufacturer and the

purchaser.

Separate auxiliary terminal box whenever provided shall meet constructional

requirements of terminal box indicated at 6 & 7. The short circuit test is not required to

be conducted on auxiliary terminal box.

14 TESTS

The following type tests shall be conducted for motor Terminal Box

(a) Degree of protection test for the terminal box (This test may also be conducted with

the TB mounted on the motor at the time of DOP Test for motor).

(b) Terminal box-fault level withstand test.

The short circuit withstand ability test may be classified as:

(i) Three phase through fault current test.

(ii) Internal arc fault current test:

--Three phase to ground internal arc fault current test for air insulated

and phase insulated boxes

--Single phase to ground internal arc fault current test.

15 TEST PROCEDURE FOR SHORT CIRCUIT TEST ON MOTOR

TERMINAL BOX

The short circuit withstand ability tests classified above may be conducted as per the

requirements of the manufacturers/purchasers. However, for guidance purpose, the test

procedure is laid below.

The terminal box used for the above tests shall be new and in good condition. The

terminal box shall be fitted with incoming and outgoing bolted terminals and with a

suitable cross section of cable of length 3 to 5 meters to be connected between the testing

source and incoming terminals of terminal box. The terminal box shall be mounted on an

iron frame in order to mount the structure firmly on the test cell. The outgoing bolted

terminals of the terminal box shall be shorted with suitable cross section of copper links

or with flexible ropes.

15.1 Test quantities

The test quantities such as short circuit current, voltage and duration of the fault current

shall be defined by the manufacturer/utility before the commencement of the test. The

11

tolerance on the current and voltage also be defined be the manufacturer/utility.

15.2 Details of Short Circuit Withstand ability Tests to be Performed

15.2.1 Through Fault Current Test - ( 3Phase through Fault Test)

For through fault current test, the terminal box is connected as per Test Circuit Diagram

given below and all the three phase outgoing terminals shorted outside the terminal box

with suitable cross section of copper links or with flexible copper ropes. The specified

short circuit current for the specified test duration shall be applied by the test source.

On completion of the test, the condition of the terminal box shall be inspected. The

terminal box is deemed to have passed the test if no external damage to the terminal box,

including pressure relief device, is noticed (other than operation of pressure relief

device).

1- Short circuit generator

2- Master breaker

3- Reactors variable in steps

4- Make switch

5- LV transformer with neutral earthed via shunt

6- Equipment under test

15.2.2 Internal Arc Fault Current Test

15.2.2.1 Three phase to ground internal arc fault current test

For three phase to ground internal arc fault current test, the terminal box is connected as

per Test Circuit Diagram given below. The three phase to ground short circuit is created

by a tinned copper wire of 0.5mm diameter cross section inside the terminal box. The

short circuit current at specified test voltage for the specified test duration shall be

applied by the test source.

On completion of the test, the condition of the terminal box shall be inspected. The

terminal box is deemed to have passed the tests if no external damage to the terminal box

12

from terminal box cover side is noticed. Pressure relief device, if any incorporated in the

terminal box, should operate safely. The damaged component if any, should either get

vented through pressure relief device or remain inside the box.

For pressure containing type, the box should neither disintegrate nor any damaged

component come out of the Terminal Box.

1- Short circuit generator

2- Master breaker

3- Reactors variable in steps

4- Make switch

5- Terminal box under test

6- Fuse element

7- Series resistors for voltage measurement

8- Current transformer for current measurement

Test conditions:

Short circuit point: grounded

Source neutral: isolated

15.2.2.2 Single phase to ground internal arc fault current test

For single phase to ground internal arc fault current test, the terminal box is connected as

per Test Circuit Diagram given below. The single phase to ground short circuit is created

by a tinned copper wire of 0.5mm dia cross section inside the terminal box. The short

circuit current at specified test voltage for the specified test duration shall be applied by

the test source.

On completion of the test, the condition of the terminal box shall be inspected. The

terminal box is deemed to have passed the tests if no external damage to the terminal box

from terminal box cover side is noticed. Pressure relief device, if any incorporated in the

terminal box, should operate safely. The damaged component if any, should either get

vented through pressure relief device or remain inside the box.

NOTES

1. For pressure containing type, the box should neither disintegrate from outside surface nor damaged component should

come out of the Terminal Box.

2. For phase separated and phase segregated box, the test shall not result in to flow of current in other two phases, which

13

are at rated voltage during the duration of the test.

1- Short circuit generator

2- Master breaker

3- Reactors variable in steps

4- Make switch

5- Terminal box under test

6- Fuse element

7- Series resistors for voltage measurement

Test conditions:

Short circuit point: grounded

Source neutral: isolated

16 TEST REPORTS

The test report for the above tests shall have all the relevant drawings of the terminal box

with complete details like:

a) Material of construction

b) Technical data sheet of terminal box

c) Oscilloscope waveform and

d) Peak to peak current observed and its duration.

------------------

Doc: ETD 15(6898)

BUREAU OF INDIAN STANDARDS

DRAFT FOR COMMENTS ONLY

(Not to be reproduced without the permission of BIS or used as Indian Standard)

Draft Indian Standard

ROTATING ELECTRICAL MACHINES PART 31: SELECTION OF ENERGY-EFFICIENT MOTORS INCLUDING

VARIABLE SPEED APPLICATIONS APPLICATION GUIDE

Last date for receipt of comments is 15-10-2015

________________________________________________________________

Rotating Machinery Sectional Committee, ETD 15

NATIONAL FOREWORD

This Indian Standard (Part 31) which is identical with IEC 60034-31 : 2007 Rotating electrical machines Part 31: Selection of energy-efficient motors including variable speed applications Application guide issued by the International Electrotechnical Commission (IEC) was adopted by the Bureau of Indian Standards on the recommendation of the Rotating Machinery Sectional

Committee and approval of the Electrotechnical Division Council.

The text of IEC Standard has been approved as suitable for publication as an Indian Standard

without deviations. Certain terminology and conventions are however not identical to those used

in Indian Standards. Attention is particularly drawn to the following:

a) Wherever the words International Standard appear referring to this standard, they should be read as Indian Standard.

b) Comma (,) has been used as a decimal marker while in Indian Standards, the

current practice is to use a point (.) as the decimal marker.

In this adopted standard, references appear to certain International Standards for which Indian

Standards also exist. The corresponding Indian Standards, which are to be substituted in their

places, are listed below along with their degree of equivalence for the editions indicated:

International Standard Corresponding Indian Standard Degree of

Equivalence

IEC 60034-1 Rotating electrical machines

Part 1: Rating and performance IS/IEC 60034-1:2004 Rotating

electrical machines Part 1: Rating and performance

Identical with

IEC 60034-1

: 2004

The technical committee has reviewed the provisions of the following International Standards

referred in this adopted standard and has decided that they are acceptable for use in conjunction

with this standard:

International Standard Title

IEC 60034-30 Rotating electrical machines Part 30: Efficiency classes of single-speed three-phase, cage induction motors (IE-code

Only the English language text of the IEC Standard has been retained while adopting it in this

Indian Standard and as such the page numbers given here are not the same as in the IEC

standard.

For the purpose of deciding whether a particular requirement of this standard is complied with,

the final value, observed or calculated expressing the result of a test, shall be rounded off in

accordance with IS 2 : 1960 Rules for rounding of numerical values (revised). The number of significant places retained in the rounded off value should be the same as that of the specified

value in this standard.

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ii

BUREAU OF INDIAN STANDARDSDraft Indian StandardLast date for receipt of comments is 15-10-20153 Terms and definitionsTable 4Minimum Creepage Distances (mm) between Phase to Earth or between Phases

Table 5Nominal Short-circuit Capacity

BUREAU OF INDIAN STANDARDSDraft Indian StandardLast date for receipt of comments is 15-10-2015