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

It would also be a bit daft to say that a double pole FCURCD with its removable fuse cannot be used as a isolator, but a single pole RCBO upfront of the circuit can or for that matter a cooker control unit switch without a removable fuse or the facility to lock it off can.


BS7671 defines isolation as:

”Function intended to make dead for reasons of safety all or a discrete section of the electrical installation by separating the electrical installation, or a section thereof, from every source of electrical energy.


Section 537 Isolation and switching starts with:

537.1  General 

This section provides requirements for:

(I) non-automatic local and remote isolation and switching measures for the prevention or removal of dangers associated with electrical installations or electrically-powered equipment and machines, and

(ii) functional switching and control.


Non-automatic local isolation surely means that you can turn the isolator off by hand and/ or pull the fuse out of it.


Table 537.4 then gives guidance on the selection of isolation devices which includes fuses, which obviously have to be removed by hand and are single pole.


Andy Betteridge 

It would also be a bit daft to say that a double pole FCURCD with its removable fuse cannot be used as a isolator, but a single pole RCBO upfront of the circuit can or for that matter a cooker control unit switch without a removable fuse or the facility to lock it off can.


BS7671 defines isolation as:

”Function intended to make dead for reasons of safety all or a discrete section of the electrical installation by separating the electrical installation, or a section thereof, from every source of electrical energy.


Section 537 Isolation and switching starts with:

537.1  General 

This section provides requirements for:

(I) non-automatic local and remote isolation and switching measures for the prevention or removal of dangers associated with electrical installations or electrically-powered equipment and machines, and

(ii) functional switching and control.


Non-automatic local isolation surely means that you can turn the isolator off by hand and/ or pull the fuse out of it.


Table 537.4 then gives guidance on the selection of isolation devices which includes fuses, which obviously have to be removed by hand and are single pole.


Andy Betteridge