Burnt out pull cord to electric shower

[Sammw123]

Hello everyone,

I have recently had a bathroom refurb in our new house as it had no bathroom fitted before. I have a 8.5kw electric shower that is isolated by a 45 amp pull cord. The shower stopped working so I had an electrician come and have a look and the pull cord wires are completely black and the plastic is melted. It never tripped the main fuse box but it is wired into a 32 amp fuse on the main box and the pull cord is 45amp will this cause it to burn? What other options are there for the burning ??? Any advice is much appreciated thr shower is fitted with a 6mm cable but I'm unsure of the size of the cable that goes from the pull cord to the fuse box...

Thanks in advance

 

[SJD]

Loose connections at the pull-cord switch.

They have to be really tight, and on stranded cable, I would tighten again after waiting a few minutes.

 

[Sammw123]

Loose connections at the pull-cord switch.

Hi the electrician said he couldnt see any loose cables to the pull cord and I have just found that the cable going from the pull cord to the fuse box is 4mm if this makes a difference

 

[ipf]

Loose connection at switch. Quite a regular occurrence due to the effort taken to replace the cover and cable movement causing the loosening.
Edit. 4m could well make a difference, as it's undersized, but a loose connection at the switch may not seem loose if it's welded. Weakest point.

 

[Midwest]

45A pull cords are the work of the devil.

 

[Strima]

Very common problem with shower switches. Using good quality switches reduces the problem but it never seems to fully go away.

 

[telectrix]

replace with acrabtree or click 50A circular switch. easier to fit and as reliable as a Toyota.

 

[ipf]

replace with acrabtree or click 50A circular switch. easier to fit and as reliable as a Toyota.

You're right, tel. Started using Crabtree when they were the first to do a 50amp. There was nowt else on the market to touch 'em.

 

[Midwest]

The other thing I find about those pull cords, is that the home owner actually use them to isolate the shower after using said shower.

I mean really.

 

[Sammw123]

The other thing I find about those pull cords, is that the home owner actually use them to isolate the shower after using said shower.

I mean really.

I turn it off after every shower ? is that not right haha

 

[telectrix]

I turn it off after every shower ? is that not right haha

it's not right. it's designed as an isolator. switchig on and off under load shortens it's life expetancy, like me having smoked 40/day for 50 years. i'm getting a bit of a cough and i'm only 73.

 

[Midwest]

I turn it off after every shower ? is that not right haha

I would not bother, your shower has a perfectly decent arrangement to turn it on & off.

Back to your issue, if the cable has suffered thermal damage, it will need cutting back to where the cable is good. That can be some distance, in some cases.

What has your electrician advised, and what has he/she said about the sizing of the cable?

 

[Sammw123]

I would not bother, your shower has a perfectly decent arrangement to turn it on & off.

Back to your issue, if the cable has suffered thermal damage, it will need cutting back to where the cable is good. That can be some distance, in some cases.

What has your electrician advised, and what has he/she said about the sizing of the cable?

The electrician took one look at it and said replace your whole fuse box? I understand the 32amp on the fuse box may need replacing for a 40 amp for the shower but this could be replaced individually not the whole fuse box? He didnt even look at the 4mm cable that leads to the fuse box and just said to call when I want the whole fuse box replacing. That's what brought me here really as that is a expensive job and if there is an alternative I would rather try that first

 

[Midwest]

The electrician took one look at it and said replace your whole fuse box? I understand the 32amp on the fuse box may need replacing for a 40 amp for the shower but this could be replaced individually not the whole fuse box? He didnt even look at the 4mm cable that leads to the fuse box and just said to call when I want the whole fuse box replacing. That's what brought me here really as that is a expensive job and if there is an alternative I would rather try that first

Hmmm easy for me to say, but why does your whole fusebox need replacing, is it somewhat old & tired?

The MCB needs to be sized in accordance with the cable size & how its installed. Likewise, a shower load should be installed with a suitably sized cable & MCB, i.e. the circuit should be designed for its load appropiately.

 

[SJD]

Perhaps post a photo of the fusebox.

 

[pc1966]

Usually the only genuine reason for replacing the CU (consumer unit = fusebox) when something is under rated is when it is so old you can't get compatible parts.
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Already mentioned is that a 8.5kW shower needs an minimum of 6mm cable (and even then not through a thermally insulated route) and generally most electricians would be selecting 10mm cable.

 

[Sammw123]

Hmmm easy for me to say, but why does your whole fusebox need replacing, is it somewhat old & tired?

The MCB needs to be sized in accordance with the cable size & how its installed. Likewise, a shower load should be installed with a suitably sized cable & MCB, i.e. the circuit should be designed for its load appropiately.

My house was built in 1991 I dont know how long they are suppose to last and the 4mm cable that supplied the fuse box comes through the loft. I am thinking a new fuse box may be easier at this point it seems there are lots of faults on the shower cabling

 

[Midwest]

If it was my house, I’d be getting more than one quote to have that fuse box replaced, and a new properly sized cable run to your shower.

 

[westward10]

Have trouble getting a Legrand breaker for that.

 

[radiohead]

An alternative solution would be to replace your 8.4kw shower with a 7.2kw unit, in which case your CU and existing 32a mcb and wiring should be adequate to leave in place. Not necessarily the best option but if your budget is tight...….