DIY removal of shower circuit...?

[Harry Bloomfield]

Unfortunately I was a bit rough with the box when making the entry hole for the cable, and the housing for one of the screws that secures the faceplate disintegrated. So I need to buy a new box.

Those boxes can be very brittle, make sure you are trying to fix it to a flat surface, or simply tightening the fixing screws, can cause them to crack.

 

[morqthana]

Those boxes can be very brittle, make sure you are trying to fix it to a flat surface, or simply tightening the fixing screws, can cause them to crack.

Buy PVC or ABS ones, not thermosetting.

 

[amfisted]

Those boxes can be very brittle, make sure you are trying to fix it to a flat surface, or simply tightening the fixing screws, can cause them to crack.

I'll be more careful with the second one, although having just checked the reviews on Screwfix ( which is something I usually do BEFORE buying) the last reviewer had exactly the same problem.

 

[amfisted]

I’m only continuing to blather on about this because it might be useful to someone else.

I bought a new back box and managed to fit it without disintegration, so the shower circuit now terminates in a socket in the loft. It’s very unlikely that I’ll ever use it, so I intend to leave the MCB for that circuit turned off until and unless required. Which brings me to my last question: probably a daft one but I have to ask. If a circuit isn’t used, with the power turned off at the CU, will the wiring deteriorate more quickly than if it’s left powered on?

 

[ebee]

No, it will not wear out any faster without electrons travelling thru it. By the way, what was the size (in Amps) of the breaker?

The reason I am asking is because, providing it is (therefore was) adequate for the existing cable run it should be OK for 1 twin socket under all conditions but if latter additions are added then if it becomes a radial or a ring there are some considerations (32A if a bog standard ring and 20A if a bog standard radial of 2.5 T & E each but 4.0 T & E as a radial would still allow you 32A anyway providing that cable lengths are not excessive) if it`s a 40A or 45A say on the existing set up and the existing cable was fit for it then one only twin socket should be fine anyway

 

[amfisted]

No, it will not wear out any faster without electrons travelling thru it. By the way, what was the size (in Amps) of the breaker?

The reason I am asking is because, providing it is (therefore was) adequate for the existing cable run it should be OK for 1 twin socket under all conditions but if latter additions are added then if it becomes a radial or a ring there are some considerations (32A if a bog standard ring and 20A if a bog standard radial of 2.5 T & E each but 4.0 T & E as a radial would still allow you 32A anyway providing that cable lengths are not excessive) if it`s a 40A or 45A say on the existing set up and the existing cable was fit for it then one only twin socket should be fine anyway

The breaker is 32amp, the shower was just 8.5kw so barely adequate, particularly in winter.

Unlikely that there will be any later additions to the circuit, but thanks for taking the trouble to post the info anyhow.

 

[ebee]

32A on an 8.5KW shower is slightly overcurrent on a breaker strictly speaking, it would be running on its curve rather than the straight part of the graph (officially) but many have been run just like that without any ill effects, I would flag it up if I saw it but it would not bother 6.0 T & E and the old cooker is not used so the circuit gets modified into a "Lasso" circuit by connecting a ring final circuit at the end of it in 2.5 T & E because it saves running new cables from the kitchen to the consumer unit. You would not normally design as this from scratch but it has been done quite a few times as a modification of what was existing.
r
I did once see a report faulting a 6.0 T & E to a 20A DP switch to an immersion heater then from that a 2.5 T & E to a second immersion heater on an adjacent cylinder and the fault reason read "Not Allowed!" .
I did question the originator why in their opinion it was not allowed and they could not answer that (2 x 3Kw immersion heaters).

I was called in to correct their listed faults but I noticed quite a few genuine faults they had not mentioned.