I have just had 2 new CU's installed in my basement. All tested well.
The feed to the garage is from a 45A MCB and its own 30mA RCD via 6/10mm T&E running the length of the house into a junction box then a section of armoured under a path.
The garage already had a protected CU, with all circuits on an RCD except one for an alarm on an RCBO so that any nuisance tripping would not upset the alarm.
On test the circuit tripped within spec with both RCD's tripping every time.
My concern is that I have now lost the benefit of having the RCBO on the alarm circuit as if there is a fault on another circuit in the garage (outside light for instance) it will take out the whole feed to the garage.
I understand that to do away with the RCD on the feed to the garage I would have to have the whole run replaced in armoured cable. This is possible but likely to be expensive and not easy.
Someone made the suggestion of fitting a 50 or 100mA RCD in the main feed to the garage.
Any thoughts?
The feed to the garage is from a 45A MCB and its own 30mA RCD via 6/10mm T&E running the length of the house into a junction box then a section of armoured under a path.
The garage already had a protected CU, with all circuits on an RCD except one for an alarm on an RCBO so that any nuisance tripping would not upset the alarm.
On test the circuit tripped within spec with both RCD's tripping every time.
My concern is that I have now lost the benefit of having the RCBO on the alarm circuit as if there is a fault on another circuit in the garage (outside light for instance) it will take out the whole feed to the garage.
I understand that to do away with the RCD on the feed to the garage I would have to have the whole run replaced in armoured cable. This is possible but likely to be expensive and not easy.
Someone made the suggestion of fitting a 50 or 100mA RCD in the main feed to the garage.
Any thoughts?