Hi, can anyone give me some advise? Just fitted a new 9.5kw electric shower to replace the old one that has never worked in my house. It pops the fuse after about 4 - 5 mins. It has a 30 amp breaker fitted, is that about right? or should it be higher?
Thanks
Mick
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Any sparky's in the house?
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Posted 2 years ago #
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The fuse is specific to the cable size, by upping it you risk the cable overheating and catching fire.
A little Googling suggests you should have 10mm cable with a 45A RCD/RCBO for 9.5kw.
Posted 2 years ago # -
As above - 9'5 kw is 40 amps so will trip a 30 W breaker and your wiring is probably not big enough for 40 amps anyway
Posted 2 years ago # -
Give me a call tomorrow Mick, I'll get hold of a breaker for you and have a look at what size cable you have in there.
Posted 2 years ago # -
I had some works done when I bought my place. The 9.5kw mira sport shower I had fitted was with 10mm cable and a 40w breaker.
I'm not a sparky, but from what you say it appears that the 30w breaker may not be up to the job.
I'd say get it checked out by a pro.
Posted 2 years ago # -
I dont know about a pro, i'll try Curly68!!! Curly, i didn't want to bother you with it, you must get it all the time aswell! I'll give you a call, think i still have your number. Thanks all!
Posted 2 years ago # -
As has already been posted, it looks like you have replaced a non operating 8.5KW shower with your new 9.5KW unit.
The current drawn by a 9.5KW shower is 39.6 Amps. The maximun current carrying capacity of a 6mm cable is 34 Amps*. A 10mm cable has a capacity of 45 Amps*.
* both these can be reduced depending on how the cable is routed!
Under no circumstances should you change the breaker for a 40A version if you have a 6mm cable. I have seen melted cables at 2 properties that I have been to sort out. Not only is it downright dangerous, but, may invalidate your insurance if you have a fire.Any work carried out in a bathroom must be carried out by a Part P registered sparky, tested, certified and notified to LABC. Additionally, the shower must be protected by a 30mA RCD or RCBO.
Posted 2 years ago # -
Bit too late on this thread - but as 49er says
DO this properly - As mentioned above, a melted cable, if not properly protected at the consumer unit could lead to a fire - which insurance will prob not cover.
Posted 2 years ago # -
Unfortunately, this is the reason that the rest of us have to mess around with getting Part P certification when we do anything to our own properties despite being more than adequately qualified (ie electrical engineers who have to pay an electrician to put a shower in).
Posted 2 years ago # -
Given that you'll be standing in water .I'd get a proper electrician to fit it.
Mess it up and the first person to use the shower could be electrocuted and killed.Posted 2 years ago # -
The current drawn by a 9.5KW shower is 39.6 Amps. The maximun current carrying capacity of a 6mm cable is 34 Amps*. A 10mm cable has a capacity of 45 Amps*.
Being a little pedantic here, but its 230Volts these days not 240volts, so it would work out at 41.3Amps.
Posted 2 years ago # -
its 230Volts these days not 240volts
we're being robbed of 10 volts. It's an outragePosted 2 years ago # -
we're being robbed of 10 volts. It's a voltrage!
Posted 2 years ago # -
its 230Volts these days not 240volts
we're being robbed of 10 volts. It's an outrage
Nah, the volts are still there. So in fact, we are getting free volts! 10 or more whole volts for free! Anyhoo, as summed up by 49er_jerry above, run a 10mm cable in if you want to use a 9.5kW shower. Will need to be RCD protected and the work is notifiable under part P. Alternatively, replace the knackered shower with one of the same rating. Such like-for-like replacements are not classed as installation work and as such, are not Part P notifiable and do not need the wiring updating with RCD etc... Probably your cheapest option, all things considered.
Posted 2 years ago # -
dudie gets it in one. as long as it is a like 4 like then part "p" is not required, but saying that how do you know the installion is correct pre part "p"
electric showers are rated 230~240 volts to allow for the voltage ups and downs but i still find a lot of sites at 251v
if not already fitted an rcd is a must for any appliance in a bathroom
like gas fitters electricans come in all shapes and sizes and i have seen to many bad ones since part "p" for sparkys and safegas (corgi)to make me feel safe at homePosted 2 years ago # -
Thanks all, i had no intention of rewiring myself! although it cant be to hard if people on here can do it
had it checked today (thanks curly!) and do indeed need an uprated breaker (wiring within spec)More money!! I only replaced the original 9.5w with one of the same power, so dont quite know how that used to work!
Posted 2 years ago # -
Unfortunately, this is the reason that the rest of us have to mess around with getting Part P certification when we do anything to our own properties despite being more than adequately qualified (ie electrical engineers who have to pay an electrician to put a shower in).
Very true quote - but rules are rules I suppose.
I am and electrical engineer and have recently re-commissioned 2 132kV -11kV grid transformers and I am currently testing most of the protection on the 11KV ccts feeding B'ham city centre - yet after I replaced my wylex fuse board for an RCB prtected one - I need a spark to check out what I done Posted 2 years ago # -
jumping_flea - Member
Unfortunately, this is the reason that the rest of us have to mess around with getting Part P certification when we do anything to our own properties despite being more than adequately qualified (ie electrical engineers who have to pay an electrician to put a shower in).
Very true quote - but rules are rules I suppose.
I am and electrical engineer and have recently re-commissioned 2 132kV -11kV grid transformers and I am currently testing most of the protection on the 11KV ccts feeding B'ham city centre - yet after I replaced my wylex fuse board for an RCB prtected one - I need a spark to check out what I doneYea it is a bit crazy I am a qualified installation electrician ( and ex aircraft electrician) and I can do anything anywhere from factorys to domestic for any company and certify my own work and provide test documentation to prove safe etc
But I am not part P registered so I cannot do my own place
HTF does that work
BTW the reason you 30a breaker does not trip immediatly is because breakers trip on a logrithmic time curve ie at 40 amps as you say about 5 minutes but at 80 amps about 3 seconds
Please get it done properly electricity is dangerous stuff lets not talk worse case scenario, but if your place burns down due to a electrical fault and it is found that cables were overloaded insurance companys will wriggle like crazy and NOT pay up
Posted 2 years ago #
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