40 amp shower on 30 amp connection
All aspects of plumbing questions and answers, help, tips and information

4 posts   •   Page 1 of 1
moconnell
Labourer
Labourer
Posts: 3
Joined: Wed Mar 21, 2007 10:01 am

40 amp shower on 30 amp connection

by moconnell » Wed Mar 21, 2007 10:09 am

My plumber fitted a new (very nice) shower that requires a 40 amp supply onto the existing wiring which is 30 amp, after 10 minutes under the shower it will cut out as the fuse trips (and is v.hot). I like the new shower and don't want a less powerful one. It is on 6 mm cabling and is directly connected through a wlex box that has 30 amp written on it. What I want to know is if I buy a replacement fuse for this box that is rated 40 amp will it work as required.

Link deleted

Cheers Matt OC

darryl
Labourer
Labourer
Posts: 1
Joined: Wed Mar 21, 2007 10:23 am

shower

by darryl » Wed Mar 21, 2007 10:52 am

hi matt its sounds as if u have installed a shower with a rating of over 8.5 kw can u check? if it is over 9 kw u will have to replace the 6mm twin earth cable with 10 mm and have a 40 amp fuse please dont be tempted just replacing the fuse of the fire risks darryl

THIS OPERATION REQUIRES CERTIFICATION BY AN ELECTRICIAN QUALIFIED TO DO SO UNDER PART P OF THE BUILDING REGULATIONS.

moconnell
Labourer
Labourer
Posts: 3
Joined: Wed Mar 21, 2007 10:01 am

Changed plan

by moconnell » Mon Mar 26, 2007 11:51 am

It wasn't over 8.5 kw but the cable was buried in plaster and maybe in a cavity wall for a long stretch so maybe that is why it was running warm. I just didn't feel comfortable with it so we've now got it running on a more modern 32 amp mcp and it seems fine now the shower does not cut off even after 1/2 an hours full power shower! Thanks for the feedback as unless I had actually felt the wire myself I would have left it as a 45 amp mcp which may have been a little dangerous I guess.
Cheers,
MOC

daveb99
Labourer
Labourer
Posts: 4
Joined: Mon Mar 28, 2011 11:02 pm

by daveb99 » Tue Mar 29, 2011 12:05 am

You can check online for a chart that tells u the size of cable to use for the size of shower and the length of the cable run.All showers i wire these days i run a 10mm cable although i had to buy a shower to run of a 30amp mcb with 6mm cable that was existing.i just used the chart and it works fine and is within the load that is suitable.

4 posts   •   Page 1 of 1
It is currently Fri Mar 29, 2024 10:49 am