8.5Kw Shower questions

[NickHewitt]

I hope we are not seeing any influences of superstitions about electric showers....

Possibly, but I don't think that alters the fact that, when an RCD is either required or deemed desirable (for whatever reason, 'valid' or not), that some of the more risk-averse amongst us will perceive merit in redundancy.

Kind Regards, John

no, it's the influence of a Degree in industrial automation and all the health & safety therein; if there's a possibility of a safety device not operating properly every time, use more than one since the probability of both developing the same fault goes from "highly unlikely" to "freak occurrence".

 

[ericmark]

You still have building warrants in Scotland so although not exactly the same law it's nearly the same. As to two RCD's every caravan and boat requires them.

 

[JohnW2]

no, it's the influence of a Degree in industrial automation and all the health & safety therein; if there's a possibility of a safety device not operating properly every time, use more than one since the probability of both developing the same fault goes from "highly unlikely" to "freak occurrence".

That's nor really a 'no' - but more an explanation for the reason for your viewpoint!

In many industries, particularly the most safety-critical ones, redundancy of safety devices is, of course, the required norm. I'm not even sure that it is any longer allowed to manufacture cars with a single braking system. However, in terms of electrical installations, neither regulatory requirements nor usual practices seem to have (yet) adopted that approach. I suppose things like "double insulation" go a little of the way down that road, but I am not aware of any real requirements for redundancy of protective devices, certainly in domestic/commercial installations.

Kind Regards, John

 

[PBC_1966]

One RCD or two RCD's, or none, I still find it rather curious that with the fuss made in the U.K. about more trivial electrical things, it's still considered perfectly acceptable to have 240V actually inside a shower enclosure behind nothing more than a flimsy plastic cover of the shower unit.

 

[JohnW2]

One RCD or two RCD's, or none, I still find it rather curious that with the fuss made in the U.K. about more trivial electrical things, it's still considered perfectly acceptable to have 240V actually inside a shower enclosure behind nothing more than a flimsy plastic cover of the shower unit.

I must say that when, many years ago, I first saw an electric shower with its case removed, I was totally taken by surprise. I had previously thought that there would be all sorts of clever measures to keep live electrical parts away from water and the outside world, yet I found myself staring those potentially 'live electrical parts' in the face, just by removing the (seemingly not 'water-tight') cover!

However, and others have pointed out, even though water, electricity and wet naked bodies in such close proximity 'sounds' pretty frightening, one does have to thing up some pretty improbable scenarios for the electricity to be able to 'get out' and do any harm!

... but back to the RCDs, IF it is decided that RCD protection is required in some situation, then to rely on a single device which may have "a few percent" probability of not operating when it should seems to be somewhat questionable.

Kind Regards, John

 

[PBC_1966]

I must say that when, many years ago, I first saw an electric shower with its case removed, I was totally taken by surprise. I had previously thought that there would be all sorts of clever measures to keep live electrical parts away from water and the outside world, yet I found myself staring those potentially 'live electrical parts' in the face, just by removing the (seemingly not 'water-tight') cover!

Some of them really do seem flimsy and certainly let water get inside. That plus if you take the cover off many after having a run a steamy hot shower for a few minutes, you'll find condensation settling on the terminals and wiring inside as well as damp on the inside of the casing from direct ingress of spray.

Yet many who accept this would almost have a fit at seeing a regular 13A socket in a bathroom, perhaps 3 or 4 ft. outside the shower/bathtub enclosure. I've always found it very odd. (No instant electric showers of the type we're talking about over here, by the way.)

 

[ban-all-sheds]

Are they allowed?

 

[Steve]

You won't need any RCD protection on a proper shower. Get a thermostatic mixer shower, and you might get something more than a dribble out of the thing, and it won't catch fire in 5 years time (NO RCD or MCB will detect loose connections in poorly designed switches which can catch fire).

 

[ban-all-sheds]

I've had electric showers for far longer than 5 years.

Why has nothing to do with them caught fire yet?

Surely you aren't superstitious, are you, and prone to giving advice based on ignorance and fear?

 

[PBC_1966]

Are they allowed?

Good question - I'm not sure if there's anything specifically within the current NEC which would prohibit them, but I've never seen anything here equivalent to the British self-contained electric showers, so if there's nothing equivalent made for the American market with UL listing, that would almost certainly preclude them since the NEC requires devices to have UL approval.

(NO RCD or MCB will detect loose connections in poorly designed switches which can catch fire).

Just wait until they start trying to sell arc-fault breakers in the U.K. Or with any luck, they won't try.