power shower isolator

[mrcrow]

my son is having his power shower isolator replaced again in just over a year as it has burnt the contact out again

he was told to shut it off each time the shower was used and put it on to take a new power shower, even though there is a on of on the power shower casing and the temperature control when set at cool wont draw power??

earlier he was told by another electrician who installed it years ago to leave it on and use the on off on the power shower casing

we cant understand why it should be switched on and off every time since it is an isolation switch and the on off indicator is to assure the user it is off before doing work on the power shower

we dont feel the latter component may have been of a high standard and ask as well if you chaps could suggest a good named component..like MK if they still do that unit

he has an mcb type consumer unit

cheers
geof

 

[Iggifer]

I quite like MK stuff generally, their shower pull cord isn't the best in their range, but it does the job.

I generally advise against using the isolator to turn the shower on and off each time, invariably, the ones I've had to change because they've failed, they've been used as a switch to turn the shower on and off.

I don't see anything wrong with just turning it off at the shower, it may use a minuscule amount of electricity in standby mode (particularly if there's a neon) but I wouldn't worry too much.

 

[sparkwright]

I have to say the MK shower pull cord is proving to be unreliable, sometimes you need to pull it several times for it to work.

The circular Crabtree ones are the only ones that seem to be any good now - though you will find them a bit different to arrange the wires...

 

[mrcrow]

I have to say the MK shower pull cord is proving to be unreliable, sometimes you need to pull it several times for it to work.

The circular Crabtree ones are the only ones that seem to be any good now - though you will find them a bit different to arrange the wires...

thanks both..i have passed that on
the crabtree i take it is a double pole switch...what is the difference in arranging the wires
at present there are two cables from the loft
one to the switch and one from the switch to the power shower

cheers again
geof

 

[JohnD]

when you say "power shower" do you mean "electric shower?"

 

[EFLImpudence]

Yes, it's double pole.

The difference in wiring is that the terminals and actual switch is in the base which screws to the ceiling.
The cover is just that.

http://www.free-instruction-manuals.com/pdf/p4470433.pdf

It is a lot easier than terminating wires in a loose switch which you then have to manipulate to get it in place to then screw to the base.

 

[bernardgreen]

An ON - OFF switch is designed to switch the load current many many times. An isolator is designed primarily to isolate a supply rather than act oas on ON - OFF switch. The type and operation of contacts will be different, ON - OFF switches often have a wiping action as the contacts colse to wipe the contacts clean. Isolators seldom have a wiping action. An isolator will ( should ) be designed to ensure isolation happens when required ands will switch full load current OFF a few time before contact wear occurs.

 

[EFLImpudence]

Not sure about wiping action on domestic accessories.

According to websites these switches are BS60669-1 which according to Table 53.4 are NOT suitable for isolation but emergency and functional switching.

 

[ban-all-sheds]

I've got an MK pull-switch for my shower. It's been used several thousand times, (and yes, I really do mean that), probably approaching 10,000, and it's still going strong.

 

[kevindgas]

just a thought, what output is the shower? is the switch a square 40A one? wouldn't be the first i've come across with a 10.5 Kw shower on a 40A pull switch and yes they are usually toasted!!

 

[mrcrow]

when you say "power shower" do you mean "electric shower?"

yes..sorry i realise power shower could be the one with a pump

cheers
geof

 

[mrcrow]

Yes, it's double pole.

The difference in wiring is that the terminals and actual switch is in the base which screws to the ceiling.
The cover is just that.

http://www.free-instruction-manuals.com/pdf/p4470433.pdf

It is a lot easier than terminating wires in a loose switch which you then have to manipulate to get it in place to then screw to the base.

when you say "power shower" do you mean "electric shower?"

yes..sorry i realise power shower could be the one with a pump

cheers
geof

all the above answer posts..thanks
what now seems to be something i will check with my son
what does he have fitted...a switch or an isolator...point taken
and
the power ratings on the shower and the newly fitted...by an electrician...item whatever it is

things get clearer each time i use this site and its big thanks to all who answered

cheers
geof

 

[ericmark]

It would seem odd for a 40A switch to burn out with the 5A or so drawn by a power shower? These showers do not heat the water they only have a small motor and pump to increase pressure. Maybe some back EMF from motor or wrong names have been used and it's not a standard power shower?

 

[ban-all-sheds]

Eric....

... there is a on of on the power shower casing ... temperature control ...

http://images.google.com/images?q=power+shower

 

[ericmark]

Eric....

... there is a on of on the power shower casing ... temperature control ...

http://images.google.com/images?q=power+shower

There are so many I suppose you are referring to this

as a typical power shower?

For one I fitted I used a standard FCU as isolator with no problems from a 6A MCB until the boiler was changed and using a power shower became illegal as a result.