Shower pull cord burning out

[bigbaddave]

I have been called back to a job where the pull cord is yet again not working. This is the sencond time they have had this fault.. Take the fitting down and the whole inside is a melted mess.. Now the shower is a 8.5kw fed on 10mm twin and earth on a 32a mcb. Install method B,

I have tested R1 + R2 and then R1 + and both exactly the same 0.07 which would tie in with the cable run. This is tested to the shower through the pull cord. ZS at shower = 0.50 (Testing with Metrel and thats the lowest reading on Loop)

Now i put the first one down do naff fitting but now im not to sure.. Has anyone else has issues with this.

Any idears fella's ?

 

[telectrix]

try the crabtree 50A pull switch, and make sure the connections are tight. with 10mm there's a lot of strain put on the cables when you force them into that silly little patress that's designed for a mx. of 6mm.

 

[Guitarist]

Without a doubt, it's down to the connections mate. If using one which has to be pushed into place, make sure you push it up, then drop it back to re-tighten.
Your best bet is to use the Crabtree, as Tel suggests. This has a "wireable" base, then the lid simply screws on.

 

[bigbaddave]

Thanks. Ill give the crabtree a go.. Wasnt aware there was much difference to be fair so never used them..

 

[Octopus]

Crabtree EVERY time after you've used on. Not the cheapest, but a couple of quid more and no call backs??

 

[eganelectrical]

Are you twisting the conductors? This can help burn it out!!

 

[Elmer BeFuddled]

Another vote for Crabtree. And if I'm too far from a Crabtree dealer (highly unlikely) I'll settle for the Click version. That's double screwed terminals as well.

 

[rmc86uk]

I always use Crabtree aswell! About 15 quid from Screwfix but I'd rather pay double the price than spending an hour trying to use a crappy cheap one with cheap and nasty box.

 

[NickD]

Now the shower is a 8.5kw fed on 10mm twin and earth on a 32a mcb. Install method B

Not relevant to your problem, but I make the MCB to be underrated. 8500/230 = 37A design current.

 

[Guest55]

you have to be a lunatic to take 10mm to a ceiling switch ,
always wall box for me if bigger than 6mm.

 

[NickD]

you have to be a lunatic to take 10mm to a ceiling switch ,
always wall box for me if bigger than 6mm.

Amen to that. I chuffing hate 10mm.

If a shower is protected by a clearly identifiable accessible double-pole RCD (which it will be to be compliant with current Regs), do you actually need a shower switch? (Reference to relevant Reg(s) appreciated.)

I mean if the RCD in question is dedicated solely to the shower.

 

[Octopus]

you have to be a lunatic to take 10mm to a ceiling switch ,
always wall box for me if bigger than 6mm.

Not if you use the Crabtree! :33:

 

[Guest154]

is it coincidence? but everyone i have ever had to change it was always the neutral side that was burnt out

 

[NickD]

Weird. I was thinking the other day it always seem to be neutral connections that burn out. Can't think of a reason as the IxR voltage drop is purely a matter of current passing through the joint, not voltage at the joint relative to earth.

 

[Elmer BeFuddled]

I've always put it down to, well the live gets a good tightening as its live, whereas the neutral.... But I'd like to know what is the real reason

 

[Guitarist]

you have to be a lunatic to take 10mm to a ceiling switch ,
always wall box for me if bigger than 6mm.

Simplicity itself with a Crabtree, as you connect the base. It's all about being firm but gentle biff

 

[NickD]

Wiring a shower in 10mm, Paul, is very much like making love to a beautiful woman ...

Swiss Tony Electrical Services.