Shower Isolator

Tuco88

Hi All,

Is it permissible to switch a shower via a contactor, being switched via the pullcord? I wouldn't have classed a contactor as a form of isolation as the contacts could weld together. Apparently due to the difficulty in connecting 10mm² to the pullcord isolator this is now the preferred method ???

Annex 537A page 448 says no, I did find a safe electric newsletter mentioning it but that was with the ET101.

Interested in hearing the opinions.

Thanks

iwillhtfu

It would certainly make sense and easy to mount in the DB. I've seen a few isolators melted due to cables being crammed into a back box. No fear of contacts welding as it's unlikely the shower will be on when closing and if rated correctly should be more than able to switch the load comfortably. Similar to a typical master/slave set up for more than one electric shower

Tuco88

I agree, and I found damage was done by miss use of the isolator too if you ask me (Switching the shower on/off with it kinda stuff)

Well I just wanted to know it was acceptable from an inspection/Safe Electric point of view. The book says no?

2011

This is an acceptable way to switch the shower but for isolation purposes it would not be considered acceptable

Tuco88

https://www.boards.ie/discussion/comment/121008896#Comment_121008896

This is much my point. I am curious that this has been allowed for showers ??? apparently 👀

Thanks for the feedback on this.

kirk.

It was allowed by mistake at some point god knows how

Its clearly not a method of local isolation

The isolator isn't designed to switch load current anyhow the shower controls are designed for that purpose

Shower just needs a quality pull cord or wall switch

meercat

https://www.boards.ie/discussion/2058310250/shower-isolator

This is the newsletter you mentioned ( bottom of page 6)

my inspector says no

ive contacted them recently with the number of fires at distribution boards whilst shower was operational

JL spark

Not with that 10sq LSF ,

don’t care how good you think the connection is ,

kirk.

https://www.boards.ie/discussion/comment/121009217#Comment_121009217

Surely it's just bad connections in the main

meercat

https://www.boards.ie/discussion/comment/121009370#Comment_121009370

Yes id agree. However I’d say more issues will arise with the terminations of 10mm into a shower pull cord switch. It’s nearly impossible to do get the cables and terminations done safely into such a tight space

kirk.

https://www.boards.ie/discussion/comment/121009436#Comment_121009436

Probably is I'm almost retirement age not involved

I never had any issues with the old 10sq t+E and crabtree pullcords I was using

I guess the new cable is more difficult to connect ?

Tuco88

https://www.boards.ie/discussion/comment/121009217#Comment_121009217

That' the one... That's covering the 4th edition too so it's old news now too.

Very interesting the opinions on the topic, I can't understand why they don't do a update or "newsletter" abut this and put it to bed once and for all. If it's not this it's the old cooker and separate oven and hob fiasco.

kirk.

It was just a mistake by one of the higher ups that caught on

Back in the day it was allowed to loop the incoming tail across the incoming side of a 2 pole neozed switchfuse on all electric homes , another workaround gone wrong

Bruthal.

Definitely not an acceptable isolation method. It is possible for the contactor to be closed via someone else remotely at the DB or becoming energised via a wiring fault. Unlikely as that may seem, it's just not a clean solid isolation method like a local isolator.

Tuco88

A 45amp wall isolator switch with a deep box is probably the way to go.

Thanks for the feedback lads.

kirk.

47mm flush box with a 35mm extension and pull-cord should be handy enough if the terminals take the earths

Drop the cables down slightly for terminating and push back up

What's the minimum size link between back box and CPC? Would 4mm do?