ELECTRIC SHOWER CABLE TOO BIG FOR TERMINAL

[trymybest]

Hi Guys, I have installed my new shower but the problem is that the cable is too big to fit into the terminal in the consumer unit. an old Wylex with plug-in MCB'S.

Can I trim a few strands off to make it fit? It still looks as if the screwhead will prevent the plug-in MCB from seating correctly, Is it ok for the MCB to be slightly out of line with the others.

Help

 

[ban-all-sheds]

Replace the CU, or at least get a separate new one for the shower.

What size is the cable, and what rating is the shower and the MCB?

 

[securespark]

No you shouldn't trim off any strands!

Sounds like you have an old Wylex board - if it has a 60A switch, you should not be running a shower in excess of 7K's anyway. Even that I think is a bit on the limit. You should also check if your main fuse and meter are up to it too. You ideally need a 100A main fuse and meter to match, plus a CU with a 100A main switch, as modern shower units are high current, and older gear was not manufactured with these stresses in mind.

 

[trymybest]

Replace the CU, or at least get a separate new one for the shower.

What size is the cable, and what rating is the shower and the MCB?

The cable is 10 mm and the MCB is 40 amp

 

[trymybest]

Replace the CU, or at least get a separate new one for the shower.

What size is the cable, and what rating is the shower and the MCB?

The cable is 10 mm and the MCB is 40 amp, the shower is 10.5 AMP

 

[ban-all-sheds]

As securespark said, you can't trim off any strands.

40A is OK for a 10mm cable, but a 40A load may be too high for your old CU, so it would be best to put in a separate one for the shower (or replace the old one completely, but that is more work).

For a separate one you want something like this:

but not that actual make - I just used that picture because all the alternatives on the TLC website show empty enclosures awaiting the fitment of RCDs & MCBs or RCBOs

You don't say if there is an RCD before the fuseboard, but if there isn't then that's another good reason to have a separate shower unit (and a good reason to replace the old fuseboard).

You'll need to feed the shower CU with tails via a service connection block (aka Henley block) - this is basically a big high-current junction box which joins the tails from the meter to other tails going off to multiple CUs. If your installation does not have an isolation switch the only way to interrupt the power will be to pull the main service fuse, and whilst many people feel that this is a safe and easy thing to do, I can't advise you to do that yourself.