Mains, pull switch, lighting adaptor, bathroom, questions!

[j0n]

Hi,

I'm involved in helping out with a bit of general refitting in a flat at the moment, and have a few questions regarding safety / correct wiring for what we're trying to achieve in the bathroom.

The general plan is that we want to replace an all-in-one striplight/shaving socket, which was wired into the lighting circuit, with a) a wall-mounted shaving socket and b) a lighting system powered by a transformer that would normally plug into the mains (not a wall-wart transformer, but wired onto a lead). We intend to install a pull-switch between the mains and the lighting.

The questions I have are mainly about the lighting wiring. So far we have:

- Mains wire coming out of the wall where the all-in-one unit was, with a 3-way wireblock on the end.

- The lighting supply with it's plug and in-line switch cut off, presenting a brown and a blue wire.

- A pull switch, with L1, L2, and COM-L connections.

- A spur of about 3ft of mains wire with which to connect the mains to the pull-switch.

Now, from a bit of web research, we've sussed out that the correct wiring should be:

Mains Neutral (black) <--(via wire block)--> Lights Neutral (blue)

Mains Live (red) <---> COM-L

Lights Live (brown) <--> L1 (or L2, apparently doesn't matter)

(Mains Earth <--> earth terminal)

ie., the switch should only connect the two live wires part of the circuit together; the two neutral wires don't go through the switch at all, but are just connected together inside the switch housing with a wire block.

Now the questions..

Is the wiring above correct?

There seems to be no earth involved here. The earth from the mains spur attaches to a metal stud in the pull-switch, which itself is isolated from anything even remotely earth-like. (Pull switch is attached to a wooden fitting on a high shelf) Is this ok?

Does anything about this setup sound in any way dangerous? It occurs to me that we're cutting the fuse part (the plug) off a normally fused device and wiring directly into the mains (albeit via a switch). Is this a bad thing? and if it needs to be fused how would this normally be achieved in this sort of situation?

Also I've heard that extending mains wiring can be dangerous in itself, putting extra load on the circuit etc. Since we're adding a spur to go to the pull switch and a spur later from the same wire block to a shaver socket about 3-4 ft away from the original wall point, does this count as extending the circuit too far?

And lastly, we're not dead-set on not hiring an electrician if it sounds like that should really be necessary. Thoughts?

Lot of questions I know, any advice is much appreciated!

Thanks,

-j0n

 

[mapj1]

If you are sure it is off the lighting circuit, then that is already lightly fused (probably 5 or 6A), so no worries about the plug fuse now missing.
IF you are worried about overloading the lighting circuit, add up the total wattage of all the lights on that fuse/circuit breaker. if its getting near 1000W, then maybe thinkking about overloaded. If not, its OK.
On a double insulated fitting (i.e. one needing no earth.) The earth wire calls in at the switch and or the ceiling fitting, but goes no further. It is however kept connected everywhere else, and lies in readiness for a later person wanting to fit something needing an earth, like a metal fitting.
BUT, is this near a sink? you have not said, but if it is in a bath room an "isolated" shaver point will be needed containing a transformer, and weighting a bit more. The light fitting should be designed for bathroom use, and all fittings must be splash and condensation proof, and/or mounted far enough from taps not to be splashed in normal use. Tahts normally taken to mean 60cm, but could be more or less depending on the design of the taps.
Also in a bathroom is the issue of cross-bonding the earth of the circuits to all exposed metal pipework. If this makes no sense, then a chat with that electrician might still be in order.
If its not a bathroom, just a sink in the loo or a bedroom, no cross-bonding is required and a non-isolated shaver point is OK. Hovever all the thoughts about condenstion and splashing are still true.

 

[bathjobby]

All I can say is; Part P building regs......

 

[mapj1]

the requirement to notify under Part P will apply if its a bathroom, not otherwise.

 

[bathjobby]

exactly;

I'm involved in helping out with a bit of general refitting in a flat at the moment, and have a few questions regarding safety / correct wiring for what we're trying to achieve in the bathroom.

 

[j0n]

mapj1 and bathjobby, thanks for the advice.

I wasn't aware of Part P at all It seems that what we're doing definitely comes under the list of things that need to be compliant, so I guess we'll be calling in an electrician.

Thanks,

-j0n

 

[mapj1]

You don't need to notify for changes of fittings, but you do for changes to the fixed wiring. You then need to either use a sparks who has paid up to belong to a self certification organisation, such as Napit, NICIEC etc, and not inform the council building control, or any spark who can provide inspection and test certificates to the satisfaction of the local building control office.
Hope that helps.