Electric shower isolation

[EFLImpudence]

Do you think the OP was correct, then?

 

[JohnW2]

Do you think the OP was correct, then?

Is that directed at me?

As far as I am concerned, even in the extremely rare situations that Bernard fears, I do not see any real need for "local isolation as in a pull cord etc in or just outside of bathroom". Unless one lives in a castle, it would surely only take 'a few seconds' more to de-energise the circuit at the CU (or wherever) than it would to operate such a 'local' emergency switch.

Kind Regards, John

 

[EFLImpudence]

No, Bernard - the previous post.

 

[bernardgreen]

it would surely only take 'a few seconds' more to de-energise the circuit at the CU (or wherever) than it would to operate such a 'local' emergency switch.

I doubt it would be just a few seconds. Opening a CU when just out of a shower, how long to dry hands enough to feel safe opening a CU ?

 

[JohnW2]

I doubt it would be just a few seconds. Opening a CU when just out of a shower, how long to dry hands enough to feel safe opening a CU ?

I have a very large house. The one electric shower I have (as a backup) is less than '20 paces' from the corresponding CU, and I doubt that it would take more than 30 secs, at most, for me to dry my hands and get to the CU, if I had to.

In any event, once one is away from the immediate vicinity of the shower, what material difference is there between 'a few seconds' and, say, one minute?

I imagine that I am far more at risk of injury from slipping in the shower or falling down the stairs than I am from "an electric shower in melt down".

Kind Regards, John

 

[John D v2.0]

Some people who would be perfectly happy pulling a cord (every time they have a shower, in many cases) wouldn't dare touch a CU, especially when still wet and with a faulty shower happening. To be honest, with a metal CU, that may not be such a bad thing, although again we're into JohnW2's specialist subject of incredibly rare problems.

I think we have determined that according to the regs as long as you have an isolator somewhere upstream, that's enough for isolation. And for functional switching that's in the shower unit.

According to how worried you are, you can have more isolators/switches or even one of these:

but don't put it within 60cm horizontally of the edge of the shower tray whatever you do

 

[JohnW2]

Some people who would be perfectly happy pulling a cord (every time they have a shower, in many cases) wouldn't dare touch a CU, especially when still wet and with a faulty shower happening.

That's true. I don't think that my other half would be happy to touch a CU, no matter what the circumstances and no matter how dry her hands were. Mind you, to her dying day my grandmother would not touch any switch, either, even if it were a pull switch (and nor would she use lifts or escalators!)

To be honest, with a metal CU, that may not be such a bad thing, although again we're into JohnW2's specialist subject of incredibly rare problems.

I wouldn't really say that it was my specialist subject - more the specialist subject of Bernard and, in a good few cases, the authors of regulations - but I do think that any perceived danger associated with operating an MCB/RCBO even with soaking wet hands would come into the category of "incredibly rare problems", even with a metal CU. My concern about metal CUs relates to people (particularly non-electricians) 'fiddling around inside them' when they are open.

I think we have determined that according to the regs as long as you have an isolator somewhere upstream, that's enough for isolation. And for functional switching that's in the shower unit.

That is, indeed, true in terms of the regs. However, it leaves 'local emergency switching' (again, not required by the regs) unaddressed, unless the 'isolator' is local to the shower.

Kind Regards, John

 

[Terry lambert]

I wonder how Terry's customer feels now, having been misled by him into spending money calling out an electrician.

I’m not an electrician so made the right call in getting it checked.

They also want the shower replaced like for like but existing may not have been to current regs, correct cable etc

 

[John D v2.0]

I’m not an electrician so made the right call in getting it checked.

To be honest, you've gone way over and above the call of duty, by the fact that you've then posted this thread to get further clarification and comments and asked if this is right.

Never stop trying to learn, then you won't go wrong.

Edit just realised you were replying to a specific comment and not to the general follow on discussion that inevitably happens, but my point above still stands.

 

[ericmark]

Since there are some here who are very concerned about the use of correct terminology, I would remind you that you are talking about "emergency switching", not "isolation".

Kind Regards, John

You are of course correct, one would expect to be able to lock off an isolator and have positive indication as to if power is on or off, which in essence shows isolation is not required and rarely provided.

 

[JohnW2]

You are of course correct, one would expect to be able to lock off an isolator and have positive indication as to if power is on or off, which in essence shows isolation is not required and rarely provided.

I think that, traditionally, the other difference was that an isolator was not required to be able to break the full design current of the circuit. Whilst that may still be true in terms of 'requirements for isolation', I think it would probably now be rare to use an 'isolator' which was not rated to break that current (at least, in domestic and commercial installations).

Kind Regards, John

 

[333rocky333]

An isolater is not only for electrical purposes, it can be used to isolate something like a shower where vulnerable people could be at risk from scalding water

 

[John D v2.0]

would probably now be rare to use an 'isolator' which was not rated to break that current (at least, in domestic and commercial installations).

Yes agreed, I can only think of rewireable fuses and dno cutout fuses that wouldn't be able to break rated current

 

[JohnW2]

An isolater is not only for electrical purposes, it can be used to isolate something like a shower where vulnerable people could be at risk from scalding water

That's obviously true, but I'm not sure that the Wiring Regs are concerned about that type of isolation, which is comparable with locking a cupboard or room which contained items (knives, tools, medicines, household chemicals etc.) which could represent a danger to such people (including children).

In the case of a shower, that sort of 'isolation'/protection could even be achieved, totally non-electrically, by switching off the water supply in some secure fashion.

Kind Regards, John

 

[JohnW2]

Yes agreed, I can only think of rewireable fuses and dno cutout fuses that wouldn't be able to break rated current

I suppose so, in some senses, but 'pulling fuses' under load is primarily a hazard to the person trying to do it, rather than a reflection of the inability of the device to 'break' its rated current. To put it another way, 'breaking capacity' is not really a characteristic (or intended use) of fuses.

Kind Regards, John