Just wondered why these are not classed as "similar switchgear" to consumer units etc which are supposed to be in
non flammable enclosures in domestics.
Regards,Hz
Alcomax:
Did you really believe that?
It is TT. 411.3.1.1, 1st paragraph: "EPC shall be connected to a protective conductor under the specific conditions for each type of earthing system as spec'd in regs 411.4 to 411.6, of which one is TT.
Where ADS is used, a cpc has to be run and terminated at each point in wiring (Reg 411.3.1.1).
Is a selective quote from the last paragraph of the reg
So, if you provide the RCD because it's TT, you provide a CPC ... and terminate it ...
Not so if that equipment does not need one because it is class II. It should, or would, not be altered by anyone else [an ordinary person] to a class 1 enclosure unless the earthing system was changed to TN or the person doing the alteration decided to take advantage of 531.3.5.3.2.201 and have a class 1 [ steel ] enclosure for the upfront RCD and make a claim on the tails being double or reinforced insulation.
412.1.2 is quite specific that the protective measure of double or reinforced insulation is not to be applied where any part has an earthing contact
I think with all that in mind, an upfront outboard RCD in a metal box is by far the worst way to go on a TT earthing system.
Alcomax:
Did you really believe that?
It is TT. 411.3.1.1, 1st paragraph: "EPC shall be connected to a protective conductor under the specific conditions for each type of earthing system as spec'd in regs 411.4 to 411.6, of which one is TT.
Where ADS is used, a cpc has to be run and terminated at each point in wiring (Reg 411.3.1.1).
Is a selective quote from the last paragraph of the reg
So, if you provide the RCD because it's TT, you provide a CPC ... and terminate it ...
Not so if that equipment does not need one because it is class II. It should, or would, not be altered by anyone else [an ordinary person] to a class 1 enclosure unless the earthing system was changed to TN or the person doing the alteration decided to take advantage of 531.3.5.3.2.201 and have a class 1 [ steel ] enclosure for the upfront RCD and make a claim on the tails being double or reinforced insulation.
412.1.2 is quite specific that the protective measure of double or reinforced insulation is not to be applied where any part has an earthing contact
I think with all that in mind, an upfront outboard RCD in a metal box is by far the worst way to go on a TT earthing system.
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