Well, if the isolator is going to be "given over" to the customer, what is the point of providing it anyway - especially if it could be argued not to comply with BS 7671 requirements for fire safety (and all a lawyer needs is an argument like this ...).


At the end of the day, the argument about the DNO device not protecting the "tails" is what it is ... I'd guess their stance is also a result of the "consumer unit fires" issue also. Basically, in every case where the metal-cased REC isolator is not considered suitable, neither is a metal-clad consumer unit that doesn't provide double insulation or equivalent for the busbars (and upstream devices) feeding the protective devices that provide shock protection.



In cases where a metal-cased isolator is not considered acceptable, but is desired, the only option that remains, if you really need a separate isolator, is to put the plastic REC isolator in a metal box, with suitable fire-rated stuffing glands for the tails ... no different to the requirement for the main CU itself.

Well, if the isolator is going to be "given over" to the customer, what is the point of providing it anyway - especially if it could be argued not to comply with BS 7671 requirements for fire safety (and all a lawyer needs is an argument like this ...).


At the end of the day, the argument about the DNO device not protecting the "tails" is what it is ... I'd guess their stance is also a result of the "consumer unit fires" issue also. Basically, in every case where the metal-cased REC isolator is not considered suitable, neither is a metal-clad consumer unit that doesn't provide double insulation or equivalent for the busbars (and upstream devices) feeding the protective devices that provide shock protection.



In cases where a metal-cased isolator is not considered acceptable, but is desired, the only option that remains, if you really need a separate isolator, is to put the plastic REC isolator in a metal box, with suitable fire-rated stuffing glands for the tails ... no different to the requirement for the main CU itself.