Consumer Units

[Tom]

In a house I moved into recently there is an old 3 wayWylex Consumer unit, wired fuse holders, 30A ring main, 5A lights, & 15A oven. At some point a separate hob has been wired in using a secondary 30A switched single way fuse box fed from the incoming tails in the Wylex CU, in addition another switched 30A single way fuse box has been wired in from the meter, this supplied an electrical shower unit in the bathroom via what I think is 7/.036 or 7/.044 twin & earth.(will check when I can borrow a micrometer) Since the shower was redundant I've used this cable to supply a secondary 4 way consumer unit (located outside the bathroom) to provide a separate supply to the bathroom, it includes earth leakage protection main switch, and 3 Mcbs, 6A-- lights& fan, shaver socket and mirror demist heater (100W).

15A-- Immersion htr. 15A--Fused switched spur to wall mounted Hair dryer.

My question is, How should the secondary CU be labelled and should the hair dryer Immersion htr etc have labelling referring to the secondary CU.What do regs say regarding labelling. I will in time have the main incoming Wylex replaced by a modern Consumer unit but it will still feed the secondary CU via the old cable. Hope that's clear, it seems a bit garbled on rereading it. Thanks Tom

[Christian McArdle]

I'd write on the secondary consumer unit

"Hairdryer" "Immersion" (or "Water Heater") and "Lights"

At the supply end fuse box, I'd write "Bathroom".

Christian.

[Tom]

Thanks for that, but is there a standard method of labelling laid down in IEE regs for multi distribution points or does that only apply in commercial/industrial buildings where more than one phase is used to balance the load on a 3Ph incoming supply. Tom

[Andy Wade]

There's no prescribed scheme for circuit numbering, if that's what you mean. The relevant requirements for identification are:

Reg. 514-01-01 requires that the purpose of each item of switchgear and controlgear is indicated, unless it's obvious.

514-01-02 requires wiring to be arranged so that it can be identified for inspection, testing, repair or alteration, "as far as is reasonably practicable." 514-03-xx to 514-07-xx are concerned with identification of conductors by means of the usual (old or new) colours. 514-08-01 requires each protective device (fuse, MCB or RCD) to be identified so that the circuit(s) protected "may be easily recognised." 514-09-01 requires documentation to be provided in the form of "a legible diagram, chart or table" (or equivalent) listing or detailing the following:

- type of each circuit, (locations of) points served, cable size & type,

- how indirect contact protection is provided (i.e. EEBADS),

- information necessary to identify each device for protection, isolation and switching,

- details of any items vulnerable to normal testing. For a domestic installation this information is usually given in the electrical installation certificate.

HTH

[Tom]

Much obliged Andy for your comprehensive reply, it's exactly the information I wanted. Since I'm retired I don't have access to IEE regs any more. Best regards Tom