Shower Switch - Required or Not

[NickD]

I'm putting in an electric shower (7kW), which will be protected (and clearly labelled as being for that purpose) by a 30mA 2-pole RCD + 32A MCB (garage/shower type connection unit - no main switch in it, just the RCD & MCB) going outside the bathroom in the airing cupboard at an easily accessible height.

Can anyone think of a reason why in addition to the RCD a dedicated shower switch (pull cord or 'cooker type' or whatever) is *required* by the regs? I've been having a read and can't immediately see anything. Section 701 (bath/shower location) doesn't seem to help. Section 537 (isolation/switching) is relaxed about an RCD being used for isolation (table 53.4)...can be secured in open position...contact positions are indicated...inadvertant closure prevented (unit has a cover)....537.3.2.2 says "shall require manual operation". Hmmm. Does it mean it must *only* be manually operated? Obviously the RCD provides ADS however it only automatically disconnects, never reconnects...

Thoughts? Cheers guys.

 

[Des 56]

Have a look at page 149 of your good book and the answer will become clear to you regarding the selection of your Rcd as an isolation device

What you won't get with the Rcd as an isolation device is a little neon light supplementing the on/off indication

 

[telectrix]

as far as i can see, it's fine.

 

[Octopus]

Best practice = fitting a switch.

Regs =ambigious = need to be clearer.

The fact that you are putting in a CU specifically for the shower makes the switch slightly less important IMHO.

If you were fitting it to a dual rcd board I'd venture to suggest that the DP switch is essential, if nothing else, so you can isolate the shower when the nuisance tripping begins.

 

[MDJ]

I'm putting in an electric shower (7kW), which will be protected (and clearly labelled as being for that purpose) by a 30mA 2-pole RCD + 32A MCB (garage/shower type connection unit - no main switch in it, just the RCD & MCB) going outside the bathroom in the airing cupboard at an easily accessible height.

Can anyone think of a reason why in addition to the RCD a dedicated shower switch (pull cord or 'cooker type' or whatever) is *required* by the regs? I've been having a read and can't immediately see anything. Section 701 (bath/shower location) doesn't seem to help. Section 537 (isolation/switching) is relaxed about an RCD being used for isolation (table 53.4)...can be secured in open position...contact positions are indicated...inadvertant closure prevented (unit has a cover)....537.3.2.2 says "shall require manual operation". Hmmm. Does it mean it must *only* be manually operated? Obviously the RCD provides ADS however it only automatically disconnects, never reconnects...

Thoughts? Cheers guys.

No reason why it is required except professionalism.

 

[NickD]

Have a look at page 149 of your good book and the answer will become clear to you regarding the selection of your Rcd as an isolation device

That be table 53.4 which I alluded to and says it's fine provided it's fit for on-load isolation which it is. That's assuming the good book you refer to isn't Bravo Two Zero by Andy McNab, which actually improves with every read (with apologies to Alan Partridge).

What you won't get with the Rcd as an isolation device is a little neon light supplementing the on/off indication

Don't want one. Under neon, loneliness. Motorcycle emptiness.....

 

[DPG]

Back of the net!

 

[NickD]

No reason why it is required except professionalism.

Why does fitting a shower switch regardless of whether it is required or not imply professionalism? I don't feel more professional if I say "I always do it this way cos I always have and everyone else does, even though you can isolate all live conductors without it and no-one ever uses the flipping thing anyway". Certainly don't feel more professional adding superfluous joints and points of failure on a (relatively!) high current circuit.

 

[MDJ]

Why does fitting a shower switch regardless of whether it is required or not imply professionalism? I don't feel more professional if I say "I always do it this way cos I always have and everyone else does, even though you can isolate all live conductors without it and no-one ever uses the flipping thing anyway". Certainly don't feel more professional adding superfluous joints and points of failure on a (relatively!) high current circuit.

Just my view, I suppose if you never had the training you wouldn't understand. To add you came here and asked a question, which meant you wanted opinions, if you don't like others opinions if they are not the same as yours then why bother to ask? what a silly world it would be if everyone thought the same and didn't have a view lol. Another serious answer is "what does the manufacturer say?" does it say on the installation instructions that local isolation or switching is required? apart from professionaliam of course, oops shouldn't have mentioned that, thats an opinion, you don't like opinions do you? lol

 

[wozz]

Nothing in the regs or manuf instructions (over what you have already suggested), well that ive found anyway.

 

[Octopus]

If I was writing the amendments to the 17th ed I WOULD insert the following reg:

"Where fixed appliances are installed on a circuit which is protected by a "shared" RCD, DP isolation must be installed to allow isolation of said appliance. This would apply to cookers, fans, showers, outside lights, outside sockets, etc, etc"


Just my thoughts.

 

[Des 56]

Certainly don't feel more professional adding superfluous joints and points of failure on a (relatively!) high current circuit.

Logical and too the point,spoken like a true proffesional

 

[MDJ]

If I was writing the amendments to the 17th ed I WOULD insert the following reg:

"Where fixed appliances are installed on a circuit which is protected by a "shared" RCD, DP isolation must be installed to allow isolation of said appliance. This would apply to cookers, fans, showers, outside lights, outside sockets, etc, etc"


Just my thoughts.

Exactly, I agree 100% and thank god we have a professional saying it as well, theres hope for the trade yet.

 

[7029 dave]

In my book there is no other way, BUT to fit one, think its just me being old school!!. lol

 

[Des 56]

Gotta be time for a poll

I have never fitted a shower without conventional local isolator, have you?



Regs aside
It would never enter my head to not fit the switch ,but aside from that,when we put one in,the vast majority of folk use it as a on/off facility
Very often I advise people to stop swinging on that string every time they finish a shower,its an isolation device not a functional switch

 

[Badged01]

We like polls!

Whilst not req'd by any regulation I can refer to, I always prefer to fit an isolator for a shower (and cooker) as I'm risk adverse and like the comfort of knowing that should anything happen there is an immediate/to-hand isolator avail for the client rather than scratching for where in the consumer unit. (Unless of course the client refuses one in which case I wont fir one!).

 

[Badged01]

p.s. and I concur that I think its 'professional' to fit one if you can --- in my opinion of course!

 

[stevethesparks]

I must admit I use mine as a functional switch, otherwise I get a bloody cold shock turning it on whilst in the shower :shocked3:

 

[mechelec]

I always fit one, it's easier to connect the fan to ; )

 

[Richard Burns]

I fitted a shower the other day and I am sure the instructions stated that the shower should be switched off at the local isolator when not in use, it is possible I may have skim read the instructions:shocked3: but this would indicate that the manufacturers instructions may require a local isolator.

OK I have just reread the instructions and the requirement from Triton is for a double pole isolation switch out of reach of the shower user and the unit must be switched off at the isolating switch when not in use.
Therefore the RCD would be suitable but should be switched off after using the shower!

 

[telectrix]

are triton so confident of the quality of their showers that they advise isolation when you;re not there? hmmmm.

 

[SirKit Breaker]

One question, a million answers. I have done similar for the same reasons, but i would install a DP switch Isolator, so you can have total isolation in the event of a problem or for maintenance.

But dont do what i once saw, and this was in an airing cupboard as well. Very nice DIY job, DIY Charlie decided in his infinite wisdom to install a small Wylex CU to house the Electricals for his shower, but as the enclosure was big enough he also installed his water isolating valve in it as well, and took great pleasure in showing me his handy work. Looked very tidy until i ripped it out, wish i had photo'd it, but it was pre smartphone days.

Cheers……………Howard

 

[guest119]

What about rcd protection for the cable from the cu to the air cupd?
Is the cable installed correctly eg >50mm under wall surface or protected? etc, etc.

Boydy

 

[NickD]

Just my view, I suppose if you never had the training you wouldn't understand.

If you would like to explain what you got from your training that means you would fit the switch regardless, then I would understand? Mine taught me that adding points of failure that cannot justify their presence is A Bad Thing, so I'm interested to hear your take on this.

To add you came here and asked a question, which meant you wanted opinions, if you don't like others opinions if they are not the same as yours then why bother to ask?

You misunderstand me. Just because I seek opinions doesn't mean that I will just take them on trust or not (politely) question them. It'd be a pretty lousy forum if we couldn't question each others' (or is it other's?) opinions. I am merely (politely) asking for further explanation about the basis on which you say that fitting a switch allegedly not required, and which as far as I can see adds nothing electrically, demonstrates professionalism. For myself, I always welcome my position being politely questioned on the basis of fact and reason, because I'm not perfect and may well be wrong and want to learn and improve; or maybe I just haven't expressed myself clearly and need to take another shot at it.

Another serious answer is "what does the manufacturer say?" does it say on the installation instructions that local isolation or switching is required?

That is a very fair question and as the shower hasn't been supplied yet I cannot yet say. However if it merely requires isolation or DP switching without being specific about locale then I will point to my RCD. Well, not literally.

 

[NickD]

What about rcd protection for the cable from the cu to the air cupd?
Is the cable installed correctly eg >50mm under wall surface or protected? etc, etc.

Surface mounted in conduit, partly for the reason that that run is indeed not RCD protected.

 

[NickD]

If I was writing the amendments to the 17th ed I WOULD insert the following reg:

"Where fixed appliances are installed on a circuit which is protected by a "shared" RCD, DP isolation must be installed to allow isolation of said appliance. This would apply to cookers, fans, showers, outside lights, outside sockets, etc, etc"

Just my thoughts.

Like it Centurion, like it. Doesn't affect my situation in hand (ooh Matron) though as the RCD is not shared - supplies only the shower.

 

[jaypp]

could the possible ambient temperature in the airing cupboard be higher than the 'allowable range' for the rcd?

 

[Myles]

"I'm putting in an electric shower (7kW), which will be protected (and clearly labelled as being for that purpose) by a 30mA 2-pole RCD + 32A MCB (garage/shower type connection unit - no main switch in it, just the RCD & MCB) going outside the bathroom in the airing cupboard at an easily accessible height. "

Why not have an rcd/rcbo at the main board and fit an isolator? Is it an old 3036 board?
What sort of heat is generated in the airing cupboard...is the unit right next to the
cylinder? Just thinking you may need to consider thermal effects..I see it's in conduit...is it run in singles? What size?

 

[NickD]

Why not have an rcd/rcbo at the main board and fit an isolator? Is it an old 3036 board?

Yeah, 1361s & 3036s. F***ing ugly enough as it is without putting the shower CU right next to it too.

What sort of heat is generated in the airing cupboard...is the unit right next to the
cylinder? Just thinking you may need to consider thermal effects..I see it's in conduit...is it run in singles? What size?

The thermal kind? ;-) It's not much above ambient. Granted I haven't got the thermometer out. Well away from the (well lagged) cylinder. 6mm T&E, partly because it allows me to switch to clips once inside the airing cupboard. Could have got away with 4mm in theory (surface mounted conduit = reference method B giving max 30A for 4mm) but cost difference is minimal and cable runs cooler and gives client flexibility to go up to higher wattage shower if one day he upgrades to a non-neolithic CU which doesn't limit you to 30A on a final circuit (you can't get higher current fuseholders to fit it).

On that distant mist-shrouded mountain top I think I can just make out the original point of the thread ;-) Joke!

 

[jaypp]

Yeah, 1361s & 3036s. F***ing ugly enough as it is without putting the shower CU right next to it too.



The thermal kind? ;-) It's not much above ambient. Granted I haven't got the thermometer out. Well away from the (well lagged) cylinder. 6mm T&E, partly because it allows me to switch to clips once inside the airing cupboard. Could have got away with 4mm in theory (surface mounted conduit = reference method B giving max 30A for 4mm) but cost difference is minimal and cable runs cooler and gives client flexibility to go up to higher wattage shower if one day he upgrades to a non-neolithic CU which doesn't limit you to 30A on a final circuit (you can't get higher current fuseholders to fit it).

On that distant mist-shrouded mountain top I think I can just make out the original point of the thread ;-) Joke!

which was?

 

[NickD]

which was?

What good justification is there, either in terms of good practice or regs, for a DP isolator switch (pullcord, cooker style, etc.) if the shower is already supplied by a dedicated DP RCD.

 

[telectrix]

What good justification is there, either in terms of good practice or regs, for a DP isolator switch (pullcord, cooker style, etc.) if the shower is already supplied by a dedicated DP RCD.

switch is needed to turn the fan connected into the shower on and off.

 

[pepparz]

i'm finding this difficult to understand, why u would be asking if a pull switch is required when you've obviously got good electrical knowledge. its is if ur testing other peoples knowledge of electrical installations on the forum? might be just me that sees it that way but hey..

 

[itselectric]

I went to a seminar lots of years ago (when electricity was being generated by hamsters) which was organised by the IEE. There were sparks there from NORWEB. who were arguing the same point, and although the chap recommended a switch was there for isolation, the NORWEB guys said the regs were just guidance and a switch was not necessary as long as there was a dedicated isolation point beside the meter.
But as we have seen on another thread recently, showers can catch fire so in the interest of safety n in my opinion, local isolation is advisable. I wouldn't want to be running about the house looking for a switch.

 

[Darkwood]

Showers are designed to house 230v within a water heavy environment now if installed and fitted correctly they should give good IP rating and service but like any accessory they are prone to life wears and tears and ageing of seals etc ... The manufacturer will often recommend a Local DP isolation point so the public are able to isolate the shower easily and quickly if water ingress should see it crackling or smoking... it is clear many householders are not familiar about the workings or even sometimes where the fuseboard is and these contribute to the recommendations of a local pullcord or switch.

You pop down to your local elderly residential area and ask them how to switch of power to the shower and they will more often than not express the shower pullcord or switch..... ask them how to isolate it at the DB and you get a whole different kind of response, in light of the above and its proximity to jets of water it is recommending that the public user has a clear understandable means of isolation and it doesn't get much clearer than a circuit design recognised by all.

 

[Darkwood]

Ps .. my views are my own here and not regulation backed but believe this argument is its own victim of changing regulations ... before rcd DP options were common place the local means of isolation for the shower was pull switch / switch, the and the method was recognised by all; public and installer but as i said before changing trends in protection has left a alternative which i believe is often argued 'correctly' as compliant but it doesn't address the advantages of a local isolation point for a shower.

 

[Geordie Spark]

i'm finding this difficult to understand, why u would be asking if a pull switch is required when you've obviously got good electrical knowledge. its is if ur testing other peoples knowledge of electrical installations on the forum? might be just me that sees it that way but hey..

He's one of Dan's mates who Dan has dropped a fiver to.

The more posts there are the more moolah Dan can stuff in his sky rocket (apparently)

You'll probably find 75% of the "Idiot Posts" on here are started in the same way and by the same bloke / blokess.

 

[NickD]

Showers are designed to house 230v within a water heavy environment now if installed and fitted correctly they should give good IP rating and service but like any accessory they are prone to life wears and tears and ageing of seals etc ... The manufacturer will often recommend a Local DP isolation point so the public are able to isolate the shower easily and quickly if water ingress should see it crackling or smoking... it is clear many householders are not familiar about the workings or even sometimes where the fuseboard is and these contribute to the recommendations of a local pullcord or switch.

You pop down to your local elderly residential area and ask them how to switch of power to the shower and they will more often than not express the shower pullcord or switch..... ask them how to isolate it at the DB and you get a whole different kind of response, in light of the above and its proximity to jets of water it is recommending that the public user has a clear understandable means of isolation and it doesn't get much clearer than a circuit design recognised by all.

Good answer.

 

[pepparz]

Who's Dan?

 

[iamelectric]

He's one of Dan's mates who Dan has dropped a fiver to.

The more posts there are the more moolah Dan can stuff in his sky rocket (apparently)

You'll probably find 75% of the "Idiot Posts" on here are started in the same way and by the same bloke / blokess.

i wouldn't say this is an idiot post i can see where he is coming from , prob about 95% of faults on shower circuits are at the DP switch , so why not cut it out , but on the other hand darkwood has also made a good point. shower ratings are getting bigger and bigger what happens in the future when your cable unavoidably runs thru insulation and your cable calcs are coming up with 16mm going to be a bit of a struggle to fit that isolator then.