This question relates to 528.1 of the wiring regs (proximity to electrical services). It states that these bands will be kept separate unless one of 6 different methods are adopted. The two exceptions im most interested in are below:
1) Every cable or conductor is insulated for the highest voltage present.
2) Each conductor of a multicore cable is insulated for the highest voltage present in the cable.
I have come across many prepayment heat metering systems where either a 5 core cable is used to take L/N/E (230V) to the prepayment unit and the remaining two conductors are used as communications (36v) between the heat meter and the prepay unit. Alternatively two separate cables are used but ran in the same trunking, both cables designed for 230v although one carrying just 36v.
Looking at the I above section of the bs7671 this looks to be ok, as far as i interpret it. I just wondered what others would say.
1) Every cable or conductor is insulated for the highest voltage present.
2) Each conductor of a multicore cable is insulated for the highest voltage present in the cable.
I have come across many prepayment heat metering systems where either a 5 core cable is used to take L/N/E (230V) to the prepayment unit and the remaining two conductors are used as communications (36v) between the heat meter and the prepay unit. Alternatively two separate cables are used but ran in the same trunking, both cables designed for 230v although one carrying just 36v.
Looking at the I above section of the bs7671 this looks to be ok, as far as i interpret it. I just wondered what others would say.