Removing wire from consumer unit

[fuzzyducky]

Hi Guys,

We recently had our boiler replaced with a combi and I'm looking to remove the old airing cupboard where the tank used to be. One of my (many) issues is that the supply for the old immersion heater is still in there and live.

After telling me it was still live the plumber recommended to tape it up and stick it in the floor - at which point I regretted hiring him.

He'd left it live into an old switch box attached to the cupboard, and at the moment I've just flipped the breaker at the CU, but I'd like at the minimum to disconnect the wire at the CU end and label up each end of the wire before sticking it under the floor.

Am I naive in assuming I can just flip the main breaker and unwire it from the CU? Or should I get an electrician in?

 

[AndyPRK]

is there a switch by the tank?

If there is just disconnect the flex to the switch.

 

[PrenticeBoyofDerry]

After telling me it was still live the plumber recommended to tape it up and stick it in the floor - at which point I regretted hiring him.

I to would have been regretting that, he's a naughty boy!

Am I naive in assuming I can just flip the main breaker and unwire it from the CU? Or should I get an electrician in?

Well that is your call, whether you feel confident enough to take the task on and have the correct equipment to identify the circuit and prove it is dead?

 

[PrenticeBoyofDerry]

is there a switch by the tank?

If there is just disconnect the flex to the switch.

Once went on a job where the plumber had removed cylinder, isolated the circuit snipped the flex to thermostat at load side of isolator, and walked away and left it!

 

[TonyW2]

surely there is a switch for the immersion. Why not disconnect just the cable from the switch to the immersion? The switch can be isolated at the CU.
That avoids working in the CU which always has incoming live at the main switch.Also leaves a supply to the switch that may be useful in the future for a socket.

 

[viewer]

If by 'main breaker' you mean that there is a switch between the meter and the CU, then, yes, there is no problem in removing the cable. If the only means of turning off all circuits is a main switch in the CU, then you can still do it, but the switch itself will remain live. In either case, you must have a way of proving the parts touchable are dead (not a neon screwdriver). Once certain that all is dead, loosen the screw at the top of the MCB serving the IH and pull out the wire. Trace the neutral and earths and disconnect those. Completely remove the whole of the cable from the CU. If for any reason this cannot be done -such as the way the cable is secured at the back of the CU-, then connect all three wires to the earth bar and attach a label to the cable. Do not leave any loose wires or cut off the cable inside the CU.

 

[fuzzyducky]

Thianks guys.

There is a switch between the IH and the wire going off to the CU, but that switch is attached to the cupboard I want to remove, and the switch now has a massive hole in it where the plumber yanked the wires for the load side out.

There is no switch between the meter and the CU, I just meant the breaker on the CU its self.

I guess it's a tossup between just leaving the breaker for the IH in the off position and hope nobody flicks it on, or getting my hands dirty opening up the CU. I'm pretty sure I could determine that the touchable parts are dead, although all I have is a multimeter to check that with.

 

[fuzzyducky]

Just a thought, but is there a way I could wire the switch where the IH was so that if anyone were to flick the breaker back on it'd just trip again?

Something like connect live neutral and earth together? Assuming that's not a mental thing to do, would that make the situation any safer?

My main worry here is that this is all in a bathroom.

 

[riveralt]

Without doubt the safest way to resolve this is to remove the circuit totally - then there are no worries about accidently turning the circuit on.
How easy it is to remove the cable from the consumer unit will depend on its type and age.
If it is a relatively modern MCB type then it is easy - if it is the old wylex semi rewireable fuses type then it is a little bit more complicated - primarily because one terminal is likely to have many cables in it.
Assuming it is the MCB type then you need to make sure the circuit is dead by opening the CU main switch - if you have an isolator between the meter and the CU even better. If there is no isolator then remember that the incoming live wires (live and neutral) are still energised. Test that the circuits are dead - Using a voltage check on the multi-meter test between the Line/Neutral Line/Earth and Earth/Neutral all should give zero reading.
If the CU circuit has been set up properly there should be one line cable to the MCB, one neutral to the neutral bar and one to the earth bar to remove - these terminals should sync with the position on the CU of the Immersion MCB.
If all this sounds too much then get an electrician in.

 

[viewer]

Just a thought, but is there a way I could wire the switch where the IH was so that if anyone were to flick the breaker back on it'd just trip again?
Not a safe, reliable idea.

Something like connect live neutral and earth together? Assuming that's not a mental thing to do, would that make the situation any safer?
It is mental.

Riveralt's advice to remove the cable completely is best and, if you can't do it yourself, just get an electrician to do it for you. In the meantime you could put tape over the MCB so it accidently can't get turned back on and put the IH switch end wires into connectors (3 separate - not into the same one). This will make it safe for you to work on the cupboard.

 

[fuzzyducky]

It's a "Steeple" branded CU with a single main switch, and has an inspection sticker saying it was fitted in 2003.

From what you say it sounds pretty straight forward - I just need to make sure to be very careful.

 

[viewer]

Yes, you should be fine. Test and if not sure stop and rethink. Give yourself plenty of time and do the job during daylight hours. A good trick is to talk yourself through it before you start. As well as the screwdriver and multimeter you will find a torch useful and, if possible, someone to hold it.
Let's know how you get on.

 

[bernardgreen]

Working on your own is not a good idea when there is a hazard.

A capable person on hand can be very useful if the hazard bites you.

 

[PrenticeBoyofDerry]

As said, the safest option is to make the circuit completely dead!
I would recommend using insulated hand tools and having an approved voltage indicator with proving unit at hand.
Also as Bernardgreen has stressed, it is unwise to work on your own.

You will require to identify the circuit.
Isolate the whole installation (best during daylight, also have at hand a torch) via the red on/off main switch, I would unload the circuits and the board prior to throwing the main switch.
This will isolate all the equipment load side of the main switch, so you will still have a live conductor within the enclosure at the incomer supple side.
You can then remove the CU cover and test.....
oh there's a vid here...
http://www.youtube.com/watch?v=MERh6H6AjdY

Then you can remove the conductors of the circuit, these cables can be completely removed, snipped and/or connected together and put out of harms way.
The isolator at the IH, can then be removed, cables removed, snipped and/or terminated together and put out harms way.

 

[fuzzyducky]

Hi All,

Thanks for all the advice. I've now removed the circuit from the CU and my worries are over.