Can someone solve my electric shower problem?

[notoriouseddie]

Hello all

New to the forum and DIY in general so go easy on me. So the story is my girlfriend and I have moved into our first home together and so far so good. After a ten hour painting session I decided to go for a long shower. The shower was fine at first but after about maybe 15'ish minutes the fuse in the fuse box blew.

I had a look at the unit (Triton Aspirante) and all seemed ok. I noticed that it is a 9.5Kw unit. I then checked the fuse box and the fuse dedicated to the shower had blown - I switched it on and all was back to normal. I noticed the fuse in the fusebox is 32amp. I found the manual and a fuse of 40/42amp is recommended so immediately I assumed the fuse wasn't big enough for the shower. My friend pop round with a meter to read how much ampage the shower was using when in use and to my suprise he said it was in the region of 20-23 amps.

Am I therefore right in saying the problem is not with the fuse box and with the shower unit itself? Any ideas how to rectify this without resorting to buying a new shower?

Cheers

 

[Aragorn84]

9.5kw at 240v is just under 40A


Remember though, the fuse (well i assume its a breaker?) is there to protect the cable, so before uprating it, you must ensure the cable is upto handling the higher current rating.

 

[mikhailfaradayski]

something doesn't add up here.

Does the shower have dual heat setting ( selected by buttons on the shower)?

If so, could it be that when your mate clamped the shower feed, the shower was on half power?

 

[Aragorn84]

or maybe the clamp meter was just crap? Or used incorrectly?


If the shower is working correctly theres no resason to assume it will be drawing any less then 40A, and the circuit should be designed to take that.

If its 6mm cable thats in there just now, then it MIGHT be acceptable to simply uprate the breaker, however it will depend on how the cable is currently installed and what derating factors you might need to apply to it.

 

[matt1e]

9.5kw at 240v is just under 40A

not this shower as its rated @ 230v

more like 43.1A @ 240

matt

 

[matt1e]

Hello all

Am I therefore right in saying the problem is not with the fuse box and with the shower unit itself?

no the fuse is defiantly underrated and maybe the cable too

matt

 

[ColJack]

while we're supposed to use 230 now in the calculations ( to appease our european neughbours ), most quoted ratings are at 240V unless it says otherwise.. it makes it sound better to say 9.5KW rather than the 8.7KW it would be at 230V..

 

[Steve]

After a ten hour painting session I decided to go for a long shower.

Yeah right

 

[briwire]

typically, posters are being pedantic and giving allsorts of information except what you want to know. So I'll try to help.

A 9.5kW shower will take more than 32A so the fuse would blow eventually. If all was OK with the shower I would expect the fuse to last quite a while before blowing. If however there is a fault, it would blow quickly, with some noise or smell somewhere.

If your mate was reading 20 odd amps, I would suspect that the power was on half power or the meter reading incorrect.

Ideally for a 9.5kW shower you would need 10mm cable with a 40A breaker. Just fitting a 40A fuse or breaker on yours would be Ok for the shower but wouldn't protect the cable from overload. The cable would overheat before the fuse blows.

Can someone with access to the regs help him?

 

[seco services]

typically, posters are being pedantic and giving allsorts of information except what you want to know. So I'll try to help.

blinding you've done well just repeated what everyone has said.

 

[briwire]

yes apart from the bickering about 230/240v.

Can someone with the regs help-seco services perhaps.

 

[seco services]

yes apart from the bickering about 230/240v.

Can someone with the regs help-seco services perhaps.

i don't need no help thanks.

 

[notoriouseddie]

Thanks for the many responses guys. Very much appreciated. And for the records, I was painting! haha

With regards to the wiring. Does 10mm wire refer to the width? circumference? cross sectional area in square mm's?

I suspect the wiring may be OK but I want to double check before putting a new breaker in

 

[DCC]

The sizes refer the the cross sectional area of the copper conductors.

 

[ban-all-sheds]

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