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.

 

[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?