I am replacing the existing 8.5kw electric shower in our ensuite bathroom. On checking the fuse in our CU (old style cartridge fuses without an RCD) I find that the fuse for the shower circuit is only 30A. My high school physics tells me that should only support 7.2kw (30Ax240V=7200W) of power. I was hoping to just replace the shower with another 8.5kw model but I'm concerned that it could be dangerous. Am I right to be concerned or am I missing something?
Replacing electric shower
- Thread starter Darwood
- Start date
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The fact it is a rewireable fuse, means that the rating of the fuse wire within the holder may be greater than 30A, if someone has incorrectly re-wired/re-fused it.
Interesting, I never thought of that. I'll take a look when I get home, thanks. The fuse itself has a machine printed 30A on it but I guess someone could possibly have got inside and changed the wire. I'm guessing if the fuse is rated too low for a 8.5kw shower it would have been blowing a fuse every time we used it?
No - a rewireable fuse will carry 1.8x its rating indefinitely.
A 30A one may pass 60A for up to 1¼ hours before it blows.
A 30A one may pass 60A for up to 1¼ hours before it blows.
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You should have a 30mA RCD fitted as well, which will more than likely be a requirement of the manufacturer anyway.
The fuse is a Hager L158 BS1361, doesn't look tampered with to me. It is similar to this and the slot it goes into on the CU says 30A too. What I basically want to know is can I just buy http://secure.tritonshowers.co.uk/electric-showers/aspirante-electric-shower-brushed-steel.html or do I need to get an electrician to come and sort it out? Thanks for your help so far.
No, you can't just buy that because even the smaller of the two draws well over 30A, which is what you are limited to.
Have an electrician look at the circuit, depending on how its wired it might be possible to have a higher rated device protecting it and therefore a more powerful shower fitted.
Personally I'd give serious thought to having it rewired to take a 10.8kW shower anyway.
Have an electrician look at the circuit, depending on how its wired it might be possible to have a higher rated device protecting it and therefore a more powerful shower fitted.
Personally I'd give serious thought to having it rewired to take a 10.8kW shower anyway.
I didn't read this
I read this, and didn't spot that it was b****cks:
I read this, and didn't spot that it was b****cks:
I can't find the non-fusing current for a 30A BS 1361, but the other two values, respectively, are 45A and 4 hours.
@Ban-all-sheds erm so can I just buy another 8.5kw or not? The old one worked fine for 8+ years so I'm guessing a new one with the same rating should be ok.
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