Disconnected neutral wire from shower MCB in CU

[Devon Dawdler]

Good evening!

Recently, after a friend’s shower stopped working, an electrician allegedly disconnected the neutral wire inside the CU, to make the shower safe and isolate the circuit. Subsequently another electrician on visiting the house, unaware of this method (if it even exists!?) concluded that the shower itself was faulty and needed replacing. Consequently, the shower was replaced, but obviously didn’t work, and then having carried out a thorough check of the circuit, did he discover that the neutral wire in the CU was disconnected from the MCB.

And on opening up the new CU, which was only fitted a month before, it was apparent that the connections were hastily attached with copper wire showing protruding above the MCB connections and not neatly looped round as is (from what I understand) good practice. Indeed it seemed as though the wires from the old fuse box weren’t adjusted, but just forced into their new housings, and in all probability not attached with the appropriate torque settings!

So, could I ask if this is an acceptable method of isolating the shower circuit, and if it’s not there was it a potentially dangerous situation to have a loose neutral wire in the CU.

Any help much appreciated.

John

 

[DPG]

Good evening!

Recently, after a friend’s shower stopped working, an electrician allegedly disconnected the neutral wire inside the CU, to make the shower safe and isolate the circuit. Subsequently another electrician on visiting the house, unaware of this method (if it even exists!?) concluded that the shower itself was faulty and needed replacing. Consequently, the shower was replaced, but obviously didn’t work, and then having carried out a thorough check of the circuit, did he discover that the neutral wire in the CU was disconnected from the MCB.

And on opening up the new CU, which was only fitted a month before, it was apparent that the connections were hastily attached with copper wire showing protruding above the MCB connections and not neatly looped round as is (from what I understand) good practice. Indeed it seemed as though the wires from the old fuse box weren’t adjusted, but just forced into their new housings, and in all probability not attached with the appropriate torque settings!

So, could I ask if this is an acceptable method of isolating the shower circuit, and if it’s not there was it a potentially dangerous situation to have a loose neutral wire in the CU.

Any help much appreciated.

John

Strange to disconnect just the neutral. Ideally both conductors would be isolated.

You say the original electrician disconnected the neutral from the MCB though - now an MCB would not normally have a neutral terminal, but I wonder if is actually an RCBO?

Have you any photos?

 

[Devon Dawdler]

Thanks DPG, for responding. And yes sorry, I probably got the terminology wrong. Attached is a screenshot of the photo I was sent.
As a layman, it occurs to me would it not be more commonplace for an electrician to remove the fuse from the shower pull chord switch, rather than switch all the house electrics off and go into the CU to disconnect the neutral wire? Anyway, your comments on the quality of wiring in the photo would also be most welcome.

 

[James]

It is probable that the black wire is not a neutral wire but that would have to be checked.

the photo shows that not a great deal of care has been used when fitting the new fuse box.

has the electrician mad the shower work now and provided you with a certificate?

 

[Devon Dawdler]

Thanks, James. The electrician just reconnected the black wire inside the CU and the shower worked no problem. As regards the issuing of a certificate, then that’s a good point. I’ll need to mention that to my friend.

 

[James]

I would expect at the least that the wires were correctly identified i.e. if the black wire is Live (going into a breaker) it should be sleeved or marked red or brown.
i would also expect some basic tests to have been done to confirm rcd times and earthing are within limits.

 

[MDJ]

an electrician allegedly disconnected the neutral wire inside the CU, to make the shower safe and isolate the circuit.

Nope, no chance, I just cannot accept that, there is no way a proper electrician would just do that, something isn't right here, my 45 years experience tells me so.

 

[mainline]

Thanks DPG, for responding. And yes sorry, I probably got the terminology wrong. Attached is a screenshot of the photo I was sent.
As a layman, it occurs to me would it not be more commonplace for an electrician to remove the fuse from the shower pull chord switch, rather than switch all the house electrics off and go into the CU to disconnect the neutral wire? Anyway, your comments on the quality of wiring in the photo would also be most welcome.

There shouldn't be a fuse in the shower pull cord switch.

It could be that he disconnected both the Neutral and Live conductors in the consumer unit. ?

 

[mainline]

Thanks DPG, for responding. And yes sorry, I probably got the terminology wrong. Attached is a screenshot of the photo I was sent.
As a layman, it occurs to me would it not be more commonplace for an electrician to remove the fuse from the shower pull chord switch, rather than switch all the house electrics off and go into the CU to disconnect the neutral wire? Anyway, your comments on the quality of wiring in the photo would also be most welcome.

Can you take a picture so that the Consumer Unit can be seen.

 

[westward10]

Could be an illusion but it looks like a cpc is not connected in the back, the copper shows a terminal screw indent on it.

 

[mainline]

Good evening!

Recently, after a friend’s shower stopped working, an electrician allegedly disconnected the neutral wire inside the CU, to make the shower safe and isolate the circuit. Subsequently another electrician on visiting the house, unaware of this method (if it even exists!?) concluded that the shower itself was faulty and needed replacing. Consequently, the shower was replaced, but obviously didn’t work, and then having carried out a thorough check of the circuit, did he discover that the neutral wire in the CU was disconnected from the MCB.

The first electrician disconnected the shower, presumably because it was faulty.

2nd electrician deems it to be faulty and is surprised when after he fits a new one that it doesn't work because it's been disconnected, something that you would expect to have been done ?? .

2nd electrician comments on how it should have been done best practice and all that good stuff.

So, could I ask if this is an acceptable method of isolating the shower circuit, and if it’s not there was it a potentially dangerous situation to have a loose neutral wire in the CU.

No electrician is just going to disconnect the neutral and leave the Live conductor connected.
The shower was probably causing a trip because of earth leakage.

 

[davesparks]

From the picture I would hazard a guess that the red conductor was not long enough to reach the new MCB and has been extended with a bit of black conductor, not ideal but when it's the only option sometimes we have to do these things. Obviously it should have been identified red to avoid this confusion.

Something I make a point of teaching apprentices is to always refer to conductors by their colour and not their usual function, it helps to avoid falling into the trap of assuming that an incorrectly identified blue (or black in this case) conductor is connected to neutral.

If the OP had said the black wire has been disconnected and shown us that picture I think a lot more people would have seen the likely scenario of using a black wire to extend the red.

 

[davesparks]

As a layman, it occurs to me would it not be more commonplace for an electrician to remove the fuse from the shower pull chord switch,

They don't contain fuses, they are just a switch.

rather than switch all the house electrics off and go into the CU to disconnect the neutral wire?

I doubt that is the neutral wire, it is more likely a live which has been extended using a bit of black.

Anyway, your comments on the quality of wiring in the photo would also be most welcome.

It is not ideal and could be improved, but you also can't expect a picture perfect, Instagram worthy, CU from that without jointing and extending all of the conductors. Obviously it would look a lot nearer if you did that, but you would also have introduced a potential point of failure into every conductor for the sake of asthetics

 

[Devon Dawdler]

Many thanks for all your replies. I will refer back to my friend with what you’ve said and act accordingly.

 

[davesparks]

Many thanks for all your replies. I will refer back to my friend with what you’ve said and act accordingly.

And the what exactly is 'acting accordingly'?