Hello, I am dealing with an office refurb and existing installation consisting of about 8 rotary isolators on a ring circuit wired with 2.5mm2 singles and fed by BS88 32Amp fuse. From as builts it appears isolators supposed to serve power poles which appears were never installed, but I would like to reuse the existing circuit to feed new HRU - about 3Amp 1ph supply. Do I need to change the circuit to radial/replace isolators with fused spurs or can I reuse one of the existing isolator? I feel I can't use the isolators but doubt arose in me when my boss said that he thinks using isolators is compliant with BS. Please let me know, thank you :)
I am not aware of anything that prohibits use of the isolators as described, BUT I feel in all likely circumstances, that either a fused connection unit or a socket taking fused plugs would be required downstream of the existing isolators. The clear intention of a 32 amp ring final or a 32 amp general purpose small power radial circuit is that loads should be connected thereto by fused plugs or by fused connection units.
Most of us would presumably not connect say a toilet extract fan, or indeed the light in a toilet to a 32 amp circuit without an intervening fuse, this sounds rather similar.
Also, equipment should be installed according to the suppliers instructions, It seems probable that the fan unit instructions will specify a maximum fuse size of a lot less than 32 amps.
I am not aware of anything that prohibits use of the isolators as described, BUT I feel in all likely circumstances, that either a fused connection unit or a socket taking fused plugs would be required downstream of the existing isolators. The clear intention of a 32 amp ring final or a 32 amp general purpose small power radial circuit is that loads should be connected thereto by fused plugs or by fused connection units.
Most of us would presumably not connect say a toilet extract fan, or indeed the light in a toilet to a 32 amp circuit without an intervening fuse, this sounds rather similar.
Also, equipment should be installed according to the suppliers instructions, It seems probable that the fan unit instructions will specify a maximum fuse size of a lot less than 32 amps.
