David's advice is along the right lines.


IEC 60320 outlets are not classed as "socket-outlets", and certainly not "standard socket-outlets" and therefore the guidance in Appendix 15 is not an appropriate analogy (Appendix 15 is specifically giving guidance on BS 1363-series socket-outlets, connection units and spurs from rings and radials in relation to Regulation Group 433.1). Instead, IEC 60320 products are referred to as:

• Cable couplers (what is on the end of flexible cable)

• Appliance outlets (as on the power strip)

• Appliance inlets (as on the power inlet of a

Collectively they would be referred to as "cable couplers" in BS 7671, if they were part of a fixed-wiring installation.


Each "power strip" is an individual piece of electrical equipment, that is connected either via:

• a 16 A or 32 A plug to a socket-outlet forming part of the fixed wiring installation (in which case a 30 mA RCD is required, unless a risk assessment is provided concluding the RCD is not required)

• some form of connection unit forming part of the fixed wiring installation (so that in theory 30 mA RCDs are not necessary in accordance with Regulation 411.3.3, although whether this is "in the spirit" of the BS 7671 requirement is open to debate)

I don't fully agree the data centre installation is outside BS 7671 - whilst I agree functional earthing, and, where required common-bonding and mesh-bonding is in accordance with BS EN 50310, BS 7671 does cover the use of the common bonding or mesh bonding network for additional protective earthing because of high protective conductor currents in the final circuits or items of equipment.

David's advice is along the right lines.


IEC 60320 outlets are not classed as "socket-outlets", and certainly not "standard socket-outlets" and therefore the guidance in Appendix 15 is not an appropriate analogy (Appendix 15 is specifically giving guidance on BS 1363-series socket-outlets, connection units and spurs from rings and radials in relation to Regulation Group 433.1). Instead, IEC 60320 products are referred to as:

• Cable couplers (what is on the end of flexible cable)

• Appliance outlets (as on the power strip)

• Appliance inlets (as on the power inlet of a

Collectively they would be referred to as "cable couplers" in BS 7671, if they were part of a fixed-wiring installation.


Each "power strip" is an individual piece of electrical equipment, that is connected either via:

• a 16 A or 32 A plug to a socket-outlet forming part of the fixed wiring installation (in which case a 30 mA RCD is required, unless a risk assessment is provided concluding the RCD is not required)

• some form of connection unit forming part of the fixed wiring installation (so that in theory 30 mA RCDs are not necessary in accordance with Regulation 411.3.3, although whether this is "in the spirit" of the BS 7671 requirement is open to debate)

I don't fully agree the data centre installation is outside BS 7671 - whilst I agree functional earthing, and, where required common-bonding and mesh-bonding is in accordance with BS EN 50310, BS 7671 does cover the use of the common bonding or mesh bonding network for additional protective earthing because of high protective conductor currents in the final circuits or items of equipment.