Switched fused spur used as throughway for control wiring

rawlins1463 · Feb 25, 2014

Ive carried out an Electrical condition report recently and found that the main switched fuse isolator for the installation has control wires running through it from a control unit mounted above the isolator to contactors mounted below the isolator. The control wires are 230V. Im sure ive read somewhere that this is not allowed but i cant find any reference to it in the regs.

Pete999 · Feb 25, 2014

Not sure of the reg number, but you shouldn't run circuit conductors for one circuit through any accessory belonging to another circuit, for obvious reasons namely safe isolation

MDJ · Feb 25, 2014

we had this very discussion not long back regarding running ring mains through fluorescent lights, definately a reg against it, not got the BGB with me this second, if no one chips in with it I will try to post it up later.

Engineer54 · Feb 25, 2014

A definite non compliance. You can't use electrical panels (of any description) or accessories as a raceway or throughway for unrelated wiring, such as being shown in the photo... But you'll have to wait for MDJ for the applicable reg number(s)

Where's ''Spinlondon'' when you need him, he could have rattled the numbers out in no time flat!! lol!!

Knobhead · Feb 25, 2014

Is the control wiring a separate circuit?

Darkwood · Feb 25, 2014

Im trying to figure out what the open P clip is all about ?

Makeshift washer?

Des 56 · Feb 25, 2014

That fuse looks like its missing a little bit of insulation

Plonker 3 · Feb 25, 2014

The only reg I can find on through wiring is 559.6.2, but that relates to light fittings only.

Darkwood · Feb 26, 2014

Lightings and the like agree but this was common as in post 1 in industrial set-ups and I've seen it often.

Bad practice and poor design at most but this set-up is seen under different circumstances as been ok ...I.E. a conduit through box with a clicks unit attached may have other circuits running through behind the click outlet. Any Electrician worth even a small part of their competence would know isolating the outlet may not isolate the wiring running through.

I obviously wouldn't do the OP example myself but other than been a bit rough where exactly is the risk, maintenance, testing and fuse replacement should be done by a competent person and they should recognise the wiring in the back may not be associated with the Sw/fuse.

This is also seen when running pipework through say a multigang grid switch with say a socket circuit running through through the back of the switch to an outlet nearby which again is common saving time and materials and may look better than multiple pipes.

A light fitting as mentioned is the actual a accessory 'load' and deffo a no no to using as a throughway for other circuits as would be a storage heater or shower unit well you get the picture.... you could always put one of E54's favourate solutions on it 'A STICKER'

- caution contains multiple circuits....

Ill stand corrected if you get dig a regulation out but it would have implications on the acceptable examples Ive given.

rawlins1463 · Feb 26, 2014

The isolator is actually the main isolator for the installation so the control wiring would be isolated when the isolator is switched off. This obviously means its not a safety issue as all wiring except the main incoming will be isolated when working in the isolator i just thought there was a reg stating not to use switchgear as a through way.

Darkwood · Feb 26, 2014

If its isolating all load side cables its nothing more than bringing a switch wire joint back through a consumer unit.

Nothing more than poor design at most for your post 1 but not contravening any regs which i know of.

Geordie Spark · Feb 26, 2014

Can't see a problem with it as long as the isolator isolates everything. Seems to me to be a tidy way of getting those "control wires" to where they need to be without sticking a bit of conduit or whatever onto the outside of the box.

Knobhead · Feb 26, 2014

The reason I asked my question. It's a bit naff but nothing I haven't seen many times before. We used a lot of BILL Imperial isolators, normal practice was to mount the E-Stop on the bottom cable box.

Don't worry about it.