Why fit a pull-cord switch for a shower?

[ringer]

I have been posed the question (by another electrician) "Why do people fit pull-cord switches in their bathrooms (for a shower)?" He challenged me to find a regulation that requires such a device be fitted.
The best I could come up with was 537.2.1.1 Every circuit shall be capable of being isolated from each of the live supply conductors ....
Is there a more specific/relevant regulation concerning this issue?

 

[DurhamSparky]

maintenance...!!!
emergency isolation...!!!
isolation after use...!!!

 

[Richard Burns]

Pull cords are fixed to the ceiling which tends to take them out of the zones so that you can fit them near the shower.
A plate switch near the shower would not be permitted.
Saves power because other wise that little red light on the shower would be on all the time if there was no switch!

Follow the manufacturers instructions which tend to say must have a double pole isolator.

 

[cjp1]

I remember going to a job to replace a faulty electric shower and the customer told us about how she never switched off the isolator one day she went to work came home in the evening to find the shower going full pelt with the shower curtain pulled back and the shower head pointed out of the bath spraying on to the bathroom floor And flooded the flat I guess she must have had a power surge and the the shower kicked in. Strangely enough I think she turns off the isolator after using the shower now.

 

[malcolmsanford]

The MCB will act as an isolator and most shower panel switches will act for the switching.

If the MCB or the panel switch is not double pole then for a TT system you will need DP isolation/switching.

If the manufacturer though ask for a double pole isolation and as above then again a DP isolator/switch will need to be fitted.

Apart from above, then there is no need to fit one. It is like a lot of things in our trade, it's seems to be the done thing.

Personally I do fit them, but if I found that one was not fitted, and it did not contravene the regs, then I would not worry to much

 

[Fin170]

Well the proper thing to do.....would be to fit a flush switch outside the bathroom, because pull cords are the traditional MK cooker switch of the bathroom world

:shades_smile:

 

[Top Cat]

:furious3:It gives me so much pleasure getting 10.0mm twin & e in to a pull switch!

 

[SirKit Breaker]

I dont think it needs anymore than Durham has said really

 

[the oracle]

As far as the Regulations are concerned, try Regulation 554.3.3, which covers 'Water heaters having immersed and uninsulated heating elements' (no, NOT electrode boilers, we are talking 'immersion type' heaters!).Electric showers contain a small tank with an instantaneous immersed water heater in it, and hence come into this category.

It states " The heater or boiler shall be permanently connected to the electricity supply through a double-pole linked switch which is either separate from and within easy reach of the heater or boiler or is incorporated therin".

If you then check Regulation 701.512.3, erection of switchgear, control gear etc etc, you will see it states that

"The following requirements do not apply to switches and controls which are incorporated in fixed current-using equipment suitable for use in that zone or to insulating pull cords of cord operated switches".

Those are the Regs that probably cover your question. Other factors like isolation, safety etc have been mentioned by other contributors already so I wont add any more. Hope that helps

The Oracle

 

[brman]

Do showers have uninsulated heating elements?

And to follow up Top Cats comment, does anyone know a pull cord isolator that isn't a complete pig to get 10mm2 into? I can't help thinking there would be a good market for one!

 

[micknew]

Do showers have uninsulated heating elements?

And to follow up Top Cats comment, does anyone know a pull cord isolator that isn't a complete pig to get 10mm2 into? I can't help thinking there would be a good market for one!

Its not to difficult if you use a deeper than standard box.

 

[brman]

Its not to difficult if you use a deeper than standard box.

Maybe I just need more practice then - last one I used a 47mm box and it was still a pig, working on steps in the corner of a room banging my elbow on the bathroom cabinet etc etc

 

[Engineer54]

As far as i know, those with experience of shower installation use the 50A Crabtree pull switch, which also facilitates easier testing by taking the neon light out of circuit by dropping the switch from the back box...

If for no other reason, the inclusion of a readily accessible isolating pull switch for anyone using the shower as an emergency means of disconnection is to say the least ''prudent'' and well worth the effort!!!

 

[DurhamSparky]

i once toyed with idea of installing a contactor in the supply to a shower at the DB/above bathroom with a operating switch located next to bathroom door

 

[malcolmsanford]

As far as the Regulations are concerned, try Regulation 554.3.3, which covers 'Water heaters having immersed and uninsulated heating elements' (no, NOT electrode boilers, we are talking 'immersion type' heaters!).Electric showers contain a small tank with an instantaneous immersed water heater in it, and hence come into this category.

It states " The heater or boiler shall be permanently connected to the electricity supply through a double-pole linked switch which is either separate from and within easy reach of the heater or boiler or is incorporated therin".

If you then check Regulation 701.512.3, erection of switchgear, control gear etc etc, you will see it states that

"The following requirements do not apply to switches and controls which are incorporated in fixed current-using equipment suitable for use in that zone or to insulating pull cords of cord operated switches".

Those are the Regs that probably cover your question. Other factors like isolation, safety etc have been mentioned by other contributors already so I wont add any more. Hope that helps

The Oracle

Well oracle I think you'll find that

1 Showers are not classed for 554.3 the same as kettles are not

2. 701.512.3 again as nothing to do with requirements for DP separate switches for showers, as this reg also includes the use of a pull cord switch for lights

 

[brman]

As far as i know, those with experience of shower installation use the 50A Crabtree pull switch, which also facilitates easier testing by taking the neon light out of circuit by dropping the switch from the back box...

If for no other reason, the inclusion of a readily accessible isolating pull switch for anyone using the shower as an emergency means of disconnection is to say the least ''prudent'' and well worth the effort!!!

Thanks, I looked at the cabtree isolator but went with what I knew in the end. Perhaps I should have tried it!

 

[oldtimer]

:furious3:It gives me so much pleasure getting 10.0mm twin & e in to a pull switch!

Never mind when they start making more powerfull showers you can do it all again with 16mm

Or why dont we just say these things have limitations because I have never seen an electric shower that is worth a ---- me like my name I am old fashioned I have the immersion heating the water then the power shower giving it big licks.

 

[Andy78]

My favourite is when you are trying to bend the 10mm cores into the box to screw the plate back, and crack !!! the backbox breaks.

 

[Des 56]

My favourite is when you are trying to bend the 10mm cores into the box to screw the plate back, and crack !!! the backbox breaks.

I think we all know the feeling and dread it
Worse than that would be the sight of the ceiling parting company with the wall when the push is in full flow

 

[Andy78]

That reminds me of a lad I worked with that second fixed a 50A pull. Another sparks gave it a go before it was energised and pulled the lot off the ceiling. The lad had not been bothered to find a joist and put the thing up on plasterboard with cavity fixings !
Much head shaking and ribbing ensued.