9.6 kW Shower connected to an MEM Fusebox via 63A 30mA Wylex RCD

[seanhfc]

Hi all. I'm a Scotland-based qualified spark.

I was thinking earlier and thought i'd ask some older and wiser sparks this one. I've been asked to change over a shower for my aunt, she had it installed a few years back. There was something wrong with the plumbing side of things, ain't entirely sure what but she requires me to simply change it over. it's a 9.6 going in.

There's a 10mm from the shower to the 45A DP switch outside the bathroom and a 10mm from the switch going back to a 45A breaker situated in a 2-Way Wylex 63A 30mA RCD. The RCD Is supplied using a 10mm connected to an old MEM rewireable fusebox. It's connected to a 45A Wylex 'push in' breaker instead of a simple 45A rewireable fuse.

All I was wondeing was wether or not the RCD should have been supplied from the cut-outs using 16mm or 25mm tails as oppossed to a 10mm cable looped fom the old board?

 

[Jimmyb]

In one word 'no' its ok on 10mm

 

[seanhfc]

I thought it would be quite adequate coming off the board seeing as it's RCD protected but just a thought i'd got in my head.

 

[oldtimer]

Your aunt has an old 3036 wylex rewireble fuses DB someone has fitted a 45A MCB and then wired it through the 63A rated RCD all via a 10mm cable so no probs but the useall set up is spurring a 10mm cable off the mains on the DB then wired to a 2 way DB with a 63A rated RCD and a 45 amp MCB why cost you can buy a 2 way garage DB with RCD fitted for less than you can buy seperate items

 

[Darkwood]

Your aunt has an old 3036 wylex rewireble fuses DB someone has fitted a 45A MCB and then wired it through the 63A rated RCD all via a 10mm cable so no probs but the useall set up is spurring a 10mm cable off the mains on the DB then wired to a 2 way DB with a 63A rated RCD and a 45 amp MCB why cost you can buy a 2 way garage DB with RCD fitted for less than you can buy seperate items

I assume you mean looping off live side of incomming switch from main dist board to 2way board, although i wouldnt say this is good practice especially with the restricted termination appartures on the old wylex boards you will effectively have created a situe that the installation has more than one point of isolation, you should be able to isolate the entire installation at one switching point (main switch), so to do this you would require to fit an isolator upstream to the tails to comply thus costing more.... the 45amp wylex mcb cost about a tenner + rcd with enclosure is the cheapest route in OP case and has already been utilised.

 

[oldtimer]

Apologies Darkwood I was not advising this but I was trying to say is this seems to be the setup when I see it and yes you are correct it should not be tapped off the live side but for some reason I see this a lot with showers and burglar alarms