Could someone please explain why you are not to have two RDC's in series unless discrimination is applied.
Eg.
Garage had a small CU with a 30mA RCCB.
House CU has had been upgraded to a dual 30mA RCD type.
Power to the garage is now RCD protected from the house CU, and still has origional RCCB
So the garage now has two RCDs in series, why is this a problem.
I understand the upstream device should operate first, with out taking out the primary device. But if I were to remove the garage RCCB, it would still take out the primary RCD.
Earthing for the house is TT.
Is there any danger from having two RCDs or is it a matter of issues caused by tripping and losing power, which may be inconvinient
Thanks
Eg.
Garage had a small CU with a 30mA RCCB.
House CU has had been upgraded to a dual 30mA RCD type.
Power to the garage is now RCD protected from the house CU, and still has origional RCCB
So the garage now has two RCDs in series, why is this a problem.
I understand the upstream device should operate first, with out taking out the primary device. But if I were to remove the garage RCCB, it would still take out the primary RCD.
Earthing for the house is TT.
Is there any danger from having two RCDs or is it a matter of issues caused by tripping and losing power, which may be inconvinient
Thanks