Outside Light Circuit

[Grant Naylor]

Hi the client has a 6A light circuit already installed to supply an outside light attached to the wall. However, the CCU is 2007 and the circuit does not have and RCD protection. A fews questions sprung to mind.

1) The light fitting would be attached to the house and fed from the existing circuit/wiring directly into the accessory and so under Part P is non-notifable. An MEIWC is needed.

2) Even though there is no light accessory, the circuit supplying the light is already there and would be unchanged so again non-notifable. No need to add RCD protection as no change to the circuit.

3) If a 6A Type B RCBO was fitted at the clients request, this would be a change to the circuit and an EIC would be needed.

Any feedback greatly appreciated.

 

[malcolmsanford]

Hi the client has a 6A light circuit already installed to supply an outside light attached to the wall. However, the CCU is 2007 and the circuit does not have and RCD protection. A fews questions sprung to mind.

1) The light fitting would be attached to the house and fed from the existing circuit/wiring directly into the accessory and so under Part P is non-notifable. An MEIWC is needed. You do not need to complete a MEIWC but the notes in the regs recommend it and so do I. Yes it is not notifiable as long as there are no outside connections

2) Even though there is no light accessory, the circuit supplying the light is already there and would be unchanged so again non-notifable. No need to add RCD protection as no change to the circuit. Again correct.

3) If a 6A Type B RCBO was fitted at the clients request, this would be a change to the circuit and an EIC would be needed. Yes as your changing the circuits characteristics then you would need an EIC and notify this as in note (b) of Table 1 of the Part P approved document

Any feedback greatly appreciated.

.................................

 

[ackbarthestar]

It appears that you have answered your own questions.

Although I'd suggest that if you do not change the MCB then you might consider a class II fitting.
If you do change to a RCBO then an EIC for that particular circuit would be required and notifiable.

 

[Deleted member 26818]

MWEICs may be used for an addition or alteration, which does not extend to the provision of a new circuit, or involve the replacement of a Distribution Board or similar.
Replacement of a CPD, is neither a new circuit or a DB (or similar).
There is no requirement to issue an EIC, when circuit characteristics are changed.
If you were to extend a circuit, the characteristics would change, if you were to shorten a circuit, the characteristics would change.
On top of that, replacing an MCB, with an RCBO, would not alter the circuit characteristics.

 

[ackbarthestar]

MWEICs may be used for an addition or alteration, which does not extend to the provision of a new circuit, or involve the replacement of a Distribution Board or similar.
Replacement of a CPD, is neither a new circuit or a DB (or similar).
There is no requirement to issue an EIC, when circuit characteristics are changed.
If you were to extend a circuit, the characteristics would change, if you were to shorten a circuit, the characteristics would change.
On top of that, replacing an MCB, with an RCBO, would not alter the circuit characteristics.

I think you have changed the circuit's characteristics by its method of protection. You are now relying upon its impedance to effect the correction operation of the RCD part of the RCBO. Which means that it would need to be certified. Whether or not it is MWEIC or and EIC is another matter.

 

[Grant Naylor]

Thanks all.