IET announces new amendment to BS 7671 (IET Wiring Regulations)

John Peckham:

I think you are missing the point.  The product standard ( BS 7288) says they are not suitable for providing Additional protection. They were removed from BS 7671 deliberately for this reason. They do not provide isolation as they do not meet the minimum contact clearance. BS 4293 was removed because because it was an obsolete standard just like BS 1361 fuses.


Are you saying that you disagree with the product standard? 

No, I’m disagreeing with that interpretation.


I don’t have access to the full BS8277:2016 and don’t feel inclined to pay the price to view the full document.


However if you Go to the BSI website  you will find a link that allows you to read the first nine pages as a preview, click this link and go to the ninth page, there you will find the introduction and scope, now bear in mind that we cannot see the next page, do we don’t know from this is we are reading the whole of the section on the scope or not.


So look at some points it makes:

• A RCD protected socket does not need an isolation function, because you can pull the appliance plug out.

• Residual current devices covered by this standard are intended for additional protection in case of direct contact only.

• SRCDs are only intended to provide supplementary protection downstream of the SRCD.

• SRCDs are intended for use in circuits where the fault protection and additional protection are already assured upstream of the SRCD.

• SRCDs are neither intended to provide an isolation function nor intended to be used in IT systems.

• Note4 For SRCDs intended to provide an isolation function or fault protection or to be used in IT systems, BS EN 61008-1 or BS EN 61009-1 should be used, as applicable, in conjunction with the requirements of BS 1363-2 for socket-outlets.

So it does not actually say that they are not suitable for providing additional protection, but it indicates there are limitations to the protection afforded by them 


Having said that we need to understand that the additional protective provisions of an installation are RCDs and supplementary equipotential bonding. So as I keep trying to tell the plumbers, the requirements for supplementary bonding has not been removed from the Wiring Regulations. Installing a RCD to protect an appliance in a special location is insufficient if any supplementary bonding that is required is not installed.


These RCD devices only offer protection downstream of them, they have to be supplied by an adequately protected electrical circuit and any bonding that is required has to be installed.


Also neither The Electricity at Work Act or BS7671 requires an isolator to be lockable if it is under the control of the person working on the electrical installation, that is why the cooker switch within two metres of the cooker is okay despite not having the means to lock it off.

so neither the sockets or the connection units need to be lockable, so long as the person working on the appliance can take control of the job site and be sure the supply won’t be unexpectedly reconnected by someone else.


Andy B.

John Peckham:

I think you are missing the point.  The product standard ( BS 7288) says they are not suitable for providing Additional protection. They were removed from BS 7671 deliberately for this reason. They do not provide isolation as they do not meet the minimum contact clearance. BS 4293 was removed because because it was an obsolete standard just like BS 1361 fuses.


Are you saying that you disagree with the product standard? 

No, I’m disagreeing with that interpretation.


I don’t have access to the full BS8277:2016 and don’t feel inclined to pay the price to view the full document.


However if you Go to the BSI website  you will find a link that allows you to read the first nine pages as a preview, click this link and go to the ninth page, there you will find the introduction and scope, now bear in mind that we cannot see the next page, do we don’t know from this is we are reading the whole of the section on the scope or not.


So look at some points it makes:

• A RCD protected socket does not need an isolation function, because you can pull the appliance plug out.

• Residual current devices covered by this standard are intended for additional protection in case of direct contact only.

• SRCDs are only intended to provide supplementary protection downstream of the SRCD.

• SRCDs are intended for use in circuits where the fault protection and additional protection are already assured upstream of the SRCD.

• SRCDs are neither intended to provide an isolation function nor intended to be used in IT systems.

• Note4 For SRCDs intended to provide an isolation function or fault protection or to be used in IT systems, BS EN 61008-1 or BS EN 61009-1 should be used, as applicable, in conjunction with the requirements of BS 1363-2 for socket-outlets.

So it does not actually say that they are not suitable for providing additional protection, but it indicates there are limitations to the protection afforded by them 


Having said that we need to understand that the additional protective provisions of an installation are RCDs and supplementary equipotential bonding. So as I keep trying to tell the plumbers, the requirements for supplementary bonding has not been removed from the Wiring Regulations. Installing a RCD to protect an appliance in a special location is insufficient if any supplementary bonding that is required is not installed.


These RCD devices only offer protection downstream of them, they have to be supplied by an adequately protected electrical circuit and any bonding that is required has to be installed.


Also neither The Electricity at Work Act or BS7671 requires an isolator to be lockable if it is under the control of the person working on the electrical installation, that is why the cooker switch within two metres of the cooker is okay despite not having the means to lock it off.

so neither the sockets or the connection units need to be lockable, so long as the person working on the appliance can take control of the job site and be sure the supply won’t be unexpectedly reconnected by someone else.


Andy B.