eaton 17th edition wiring regs€¦ · protection by means of an rcd with idn not exceeding 30 ma...

© 2007 Eaton Corporation. All rights reserved.

BS 7671 : 2008WIRING REGULATIONS 17th EDITION

A Review of the Forthcoming New Wiring Regulations with Specific Reference to Increased Requirements for use of Residual Current DevicesPresented by David Pitt

2

Wiring Regulations 17th Edition

• BS 7671 : 2008 ‘Requirements for Electrical Installations’ is to be published on January 1st 2008 and comes into effect on June 1st 2008.

• Installations designed after 1st June 2008 are to comply with BS 7671:2008

3


HistoryFor over 100 years the IEE (now the IET - Institution of Engineering & Technology) have been responsible for promoting electrical safety in industry and to the public. The IEE issued their first Wiring Rules in 1882 – all of 4 pages and 21 Regulations! 16th edition is 321 pages long

4

Wiring Regulations 17th EditionWhat’s new relating to Use of Residual Current Devices?

Chapter 41 Now requires that additional protection by means of an RCD with I∆n not exceeding 30 mA and trip time not exceeding 40mS at 5 I∆n be provided for socket outlets with a rated current not exceeding 20A that are for use by ordinary persons and intended for general use and for mobile equipment with a current rating not exceeding 32A for use outdoors.

5

Wiring Regulations 17th EditionWhat does this mean?This additional protection will need to be provided in the event of failure of the provisions for basic protection and/or the provision of fault protection or carelessness by users of the installation.

Certain exceptions are permitted:•Socket outlets for use by skilled personnel (I.e. in some commercial or industrial installations).

•A specific labelled socket outlet for connection of a particular item of equipment (I.e. a freezer on it’s own circuit)

6

Wiring Regulations 17th EditionWhat’s new relating to Use of Residual Current Devices?

Range In (A) Disconnection 0.4s

Disconnection 5s

Type B (MBH / MBL) 1 46.000 46.000 Type B (MBH / MBL) 2 23.000 23.000 Type B (MBH / MBL) 4 11.500 11.500 Type B (MBH / MBL) 6 7.667 7.667 Type B (MBH / MBL) 8 5.750 5.750 Type B (MBH / MBL) 10 4.600 4.600 Type B (MBH / MBL) 13 3.539 3.539 Type B (MBH / MBL) 16 2.875 2.875 Type B (MBH / MBL) 20 2.300 2.300 Type B (MBH / MBL) 25 1.840 1.840 Type B (MBH / MBL) 32 1.438 1.438 Type B (MBH / MBL) 40 1.150 1.150 Type B (MBH / MBL) 50 0.920 0.920 Type B (MBH / MBL) 63 0.730 0.730

��

Chapter 41 Also includes revised earth loop impedance tables based on a nominal voltage of 230V (previously 240V), hence the values are slightly reduced.

What does this mean?Possible that normal overcurrentdevices may not achieve the required disconnection time without the addition a residual current device

7

Wiring Regulations 17th EditionWhat’s new relating to Use of Residual Current Devices?Chapter 52 It is now permitted to protect cables concealed in a wall or partition by a 30 mA RCD if the normal

methods of protection including use of cables with an earthed metallic covering, mechanical protection or the use

of the safe zones cannot be employed.

What does this mean?An alternative method of compliance with the Regulations using an RCD when ‘normal’ mechanical methods of cable protection within walls or partitions cannot be employed.

8


What’s new relating to Use of Residual Current Devices?

Section 701 Locations containing a bath or shower basin.

• Now only zones 0, 1 & 2

• Socket outlets permitted - must be 3m horizontally beyond the boundary of Zone 1

• For all circuits in this location, including lighting circuits, must have 30mA RCD protection

9

Wiring Regulations 17th EditionPart 7 – Examples of other section changes relating to increased use of RCDs702 Swimming pools & other basins

703 Rooms & cabins containing sauna heaters

704 Construction & demolition sites

705 Agricultural & horticultural premises

708 Caravan & camping parks

709 Marinas & similar locations

711 Exhibition shows & stands

717 Mobile or transportable units

721 Electrical installations in caravans & motor caravans

740 Temporary electrical installations for structures / fairgrounds etc.

735 Floor & ceiling heating systems

10


Conclusions• Examples follow to show the types of products that will be

needed in greater quantities from June 2008 to comply with the new Wiring Regulations

11


RCCBs for Single or Multi Circuit Protection

12


RCBOs for Consumer Units or Distribution Boards

13


Split Load Consumer units with 30mA Protected Section

14


RCD Socket Outlets

15


Conclusions• The new Regulations create Distributor margin

opportunities by in increasing demand for RCD protection, particularly at the 30mA level

• Additional loose sale for RCCB’s

• Opportunities for more Split Load boards

• Opportunities to sell high value RCBO’s in all Consumer Units and distribution Boards

eaton 17th edition wiring regs€¦ · protection by means of an rcd with idn not exceeding 30 ma...

Documents