Help, shower cable overheating

[Thebear101]

Hi I've fitted a new shower with a 10 mm cable connected from a 45 amp breaker (neutral to neutral bar and earth to earth bar) to a 45 amp double pole switch then to the shower. Once the shower has been running for about 10 mins the neutral in the consumer starts to seriously overheat, any ideas on where I've gone wrong?

 

[Lucien Nunes]

12kw 100m from the board will get the cable hot

Eh? longer cable... more resistance... lower current... cooler cable...

 

[Marvo]

Have you calculated the correct cable size for the shower and distance? 12kw 100m from the board will get the cable hot

Hmmm, not really but volt drop might become an issue.

**edit** Beaten by Lucien

 

[Baker1988]

Thry didn't teach me that at college and every sparky I've worked alongside has just used normal screwdrivers. Must see if I can get one

They did not teach me that either but I am aware that people use them, I have never seen a electrician useing them not one, I would like some my self but cant justify the price

 

[Silly Sausage]

They did not teach me that either but I am aware that people use them, I have never seen a electrician useing them not one, I would like some my self but cant justify the price

I think it stems from manufacturers instructions in CUs and following them in the regs bollox.

I wouldn't mind trying one, just to compare the tool torque v wrist action actually.

 

[Tiny Spark]

I think it stems from manufacturers instructions in CUs and following them in the regs bollox.

I wouldn't mind trying one, just to compare the tool torque v wrist action actually.

I to would be interested in finding that out.
Am I to heavy handed or to light.....
I suspect heavy handed but I have not had any loose connection problems yet so i guess ime not doing to badly.....

 

[ayjay]

what would be the correct torque setting in ft pounds ideally, for the 10mm cable terminal screw?

 

[Silly Sausage]

what would be the correct torque setting in ft pounds ideally, for the 10mm cable terminal screw?

About quarter past three!

 

[ayjay]

thats the answer i expected

 

[HappyHippyDad]

I'd have a read of Telectrix's posts about normal warming of cables? A shower cable can get hot depending on how much current is going through it, although if it is that then you would expect the line to be hot as well.

Also, accredited cables, Basec etc, are rated at up to 70c which would feel pretty hot!

Can you keep your hand on it? Is the DP switch getting hot? Does the line conductor get hot? What kW is the shower?

......................

ps... after second thoughts dont try and keep your hand on the neutral in a live CU!!!!

 

[Dipzy]

just use an impact driver LOL

 

[Jamie]

just use an impact driver LOL

As do I, Bosch 10.8v impact perfect for consumer unit changes/work

Tug test afterwards, and then double check with screwdriver after all work is done on each screw, jobs a good un

 

[ayjay]

so--to summarise so far
the correct torque of a 10mm shower cable in a neutral termination is determined by using an impact screwdriver or battery drill
and not some kind of torque wrench as has been mentioned ?

 

[Dipzy]

Jamie I was jesting. :smilewinkgrin:

There was another thread on here recently, with pics of an 18volt impact driver doing up a consumer unit.

I use an old yankee screwdriver yee haaa !!!!

 

[Jamie]

so--to summarise so far
the correct torque of a 10mm shower cable in a neutral termination is determined by using an impact screwdriver or battery drill
and not some kind of torque wrench as has been mentioned ?

you don't need any fancy tools, you will know when it's tight by only using a screwdriver, do the tug test afterwards

Jamie I was jesting. :smilewinkgrin:

There was another thread on here recently, with pics of an 18volt impact driver doing up a consumer unit.

I use an old yankee screwdriver yee haaa !!!!

ah :redface:, but they are very good, maybe the 18v is a bit much, but the smaller 10.8 is perfect imo, Im not on about going nuts and holding the trigger so there's no head left on the screw, but just to do the majority of the work then check with screwdriver after, worked well for the past year anyway

 

[edexlab]

 

[edexlab]

Is that you Jamie lol

 

[ayjay]

i know jamie was jesting
i still want to know the tourque setting for the neutral term though and a pic maybye of said tool

 

[Geordie Spark]

Oh yes!!!!

NOW you're torquing!!!

 

[PEG]

...Not the torque screwdriver debate again? ...just practice,practice and use your senses...torque limiting drivers do not take into account other factors. This is part of the reason some structural steel work and other critical assembled items such as cylinder heads,steering components etc are "angle rated" from a base torque or position. Next we'll be using "acceptable impact force interfaces" fitted to the end of bolsters,so we know we are hitting them hard enough...lets give the trainees of tomorrow something to add to experience....confidence. Then,when they have BOTH,they can blow their wages on any clicky tool-box ornaments they fancy :stooge_curly: