Electrical shower

[Cj24]

Hi Iv been to someone's house who said there shower pull cord sw was smelling of fish so I opened up the pull cord to find the Neutral on the supply side was melting and the copper was all black and the switch was melting as you could see the plastic slightly disformed so the smell was surely the burning of the plastic, I remade connection off and reused the same switch as a temp measure, the guy ordered new sw and was getting back to me but not heard anything then 3 weeks later I get a call saying smells back so Iv been round and changed for new switch but the supply Neutral had started to melt again, any ideas? And do you think it will happen again? It is 8.5kw shower and 10mm cable and it's a short distance from the board do you just think it was a loose connection? As I can't see what else it could be

 

[Engineer54]

Undoubtedly a loose neutral connection, not many of these pull cord switches are really very suitable to accommodate 10mm T&E cables, so they tend to pull on cable connections when fixing faceplate to pattress. The only pull cord switch i would entertain on a UK domestic shower installation is the Crabtree 50A unit....

 

[Pete999]

What Eng said deffo

 

[Lukethoma1985]

Yep deffo, pay abit extra and get the crabtree

 

[Octopus]

So the end user fitted the new switch? No doubt it'll be cheap and nasty!

Got and get a Crabtree 50A as others have said and you fit it!

 

[7029 dave]

As all above, NB never remake an melted switch no matter how temp it is, when their knacked ---- it in the bin.!!

 

[Cj24]

Thank you

 

[Octopus]

I think you fell into the classic DIYer trap here by letting him source the part(s).

Its worth keeping a Crabtree on the shelf so that in such situations you can get it, and install it as part of the origin call.....

 

[Richard Burns]

I would agree with the above posts, also a heat damaged cable can have surface corrosion further down the cable so the end must be clean copper in order to remake the connection safely.
Since the first change was done by the customer they probably did not clean or securely terminate the cable so the problem resurfaced.

 

[SJD]

As Richard says, the cable can be damaged a fair way down - overheated discoloured copper, and also overheated brittle insulation - if there is spare cable, you might be able to cut this off and remake the connections on good cable; if not then you might need to clean the copper and also replace damaged insulation e.g. with heatshrink sleeving.

After tightening up the connections and pushing the switch into the mounting box, the twisting of the cable strands as you do this can make the connection somewhat loose - I like to tighten the screws at least a couple of times.

 

[D Skelton]

What is everyone's obsession with replacing burned out shower isolators?!

Get rid of the weak link altogether! Crimp the joints and fit blanking plate. The isolator isn't even needed in the first place and I for one never understand the reason behind so many people installing them when running in a new electric shower feed?!

 

[Octopus]

What is everyone's obsession with replacing burned out shower isolators?!

Get rid of the weak link altogether! Crimp the joints and fit blanking plate. The isolator isn't even needed in the first place and I for one never understand the reason behind so many people installing them when running in a new electric shower feed?!

MI's!!

 

[D Skelton]

MI's!!

And?

Check out these MIs! I'm so glad they're doing away with that reg in January!

 

[Octopus]

Yeppee, now more messing around with 3A fuses for fans!

Wonder that the NICEIC will have to say about this!

 

[davesparks]

I can honestly say I've never fitted a 3A fuse for a fan when it's fed from a normal lighting circuit.

I do however fit isolators for fixed equipment, whether it's a shower or any other fixed kit.