Replacement Shower

[Bloosman]

Hi,

I posted in the Plumbing area, but as this is really an electrical issue, I was advised to stick my query here...

I'm replacing our ancient 8.5kw shower with a newer model - same rating - and whilst checking the wiring etc. I discovered that the wall mounted switch (with neon light) on the external bathroom wall which supplies power to the shower, appears to be wired incorrectly...

The cable (which appears to be 10mm with L-N-E all braided) coming from the Consumer Unit is wired into the terminals on the switch labelled "out", whilst the cable from the shower are wired to the terminals labelled "in".

The shower has operated fine over the past 20 years, so I'm thinking it can't be all that bad...???

The neon light only comes on when the shower is switch on, as I believe it should.

Consumer Unit shows it wired to an MCB labelled B40 61/B40, so I'm assuming 40 amps...?

Anyone able to assist me...?

Dougie.

 

[EFLImpudence]

The neon light only comes on when the shower is switch on, as I believe it should.

It must be wired correctly, then, unless it is wired the wrong way round and someone has put the neon in the other end. If so it doesn't matter

Consumer Unit shows it wired to an MCB labelled B40 61/B40, so I'm assuming 40 amps...?

Correct.

 

[Bloosman]

The neon light only comes on when the shower is switch on, as I believe it should.

It must be wired correctly, then, unless it is wired the wrong way round and someone has put the neon in the other end. If so it doesn't matter

Consumer Unit shows it wired to an MCB labelled B40 61/B40, so I'm assuming 40 amps...?

Correct.

Thanks....

The neon is wired to the "out" terminals which the power supply is attached to...so it would appear to have been altered when installed originally.

 

[EFLImpudence]

The neon is wired to the "out" terminals which the power supply is attached to...so it would appear to have been altered when installed originally.

It should be in the 'out' terminals.

Are you mistaken about which cable is which?

 

[JohnW2]

The neon is wired to the "out" terminals which the power supply is attached to...so it would appear to have been altered when installed originally.

As has been said, something is wrong with what you are telling us, since ....

.... The neon light only comes on when the shower is switch on, as I believe it should.

Assuming you mean that the neon comes on only when the wall switch (which includes the neon) is switched on, then this is not compatible with what you say above. If it were connected to the same terminals as the supply (which obviously would be 'wrong'), the neon would be on regardless of whether the witch was on or off.

The neon should be connected to the 'out' terminals, and should only be on when the switch is on, but it should be the shower, not the supply, which is also connected to those 'out' terminals'. Since the neon is working correctly, it sounds as if the wiring is also correct, even though you think it is wrong.

Kind Regards, John

 

[Bloosman]

The neon is wired to the "out" terminals which the power supply is attached to...so it would appear to have been altered when installed originally.

As has been said, something is wrong with what you are telling us, since ....

.... The neon light only comes on when the shower is switch on, as I believe it should.

Assuming you mean that the neon comes on only when the wall switch (which includes the neon) is switched on, then this is not compatible with what you say above. If it were connected to the same terminals as the supply (which obviously would be 'wrong'), the neon would be on regardless of whether the witch was on or off.

The neon should be connected to the 'out' terminals, and should only be on when the switch is on, but it should be the shower, not the supply, which is also connected to those 'out' terminals'. Since the neon is working correctly, it sounds as if the wiring is also correct, even though you think it is wrong.

Kind Regards, John

John...

I've just checked the rear of the wall switch again....

Cable from the shower is wired to the terminals marked "IN", which is at the top of the switch.

Cable from the supply is wired to the terminals marked "OUT", at the bottom of the switch.

The neon at the top of the switch is also wired to the terminals marked "OUT", so they are on the side coming from the supply.

The neon is only illuminated when the switch is "ON", at which point the shower heats the water.

Dougie.

 

[JohnW2]

I've just checked the rear of the wall switch again....
Cable from the shower is wired to the terminals marked "IN", which is at the top of the switch.
Cable from the supply is wired to the terminals marked "OUT", at the bottom of the switch.
The neon at the top of the switch is also wired to the terminals marked "OUT", so they are on the side coming from the supply.
The neon is only illuminated when the switch is "ON", at which point the shower heats the water.

Well, that's exactly the same as you have been telling us all along - but as I and others have been saying, it doesn't really make sense If the neon really were connected to the supply (connected to the same terminals as the supply) it would obviously be lit all the time, regardless of the switch.

I don't really know what else to say or ask - and it's unusual for me to me lost for words! Are you absolutely certain that the neon is wired to the same ('out') terminals as the supply? Is the neon literally connected into the same terminals of the supply, or does it have separate terminals or something like that?

Kind Regards, John

 

[Bloosman]

DOH.....!!!!!!!!!!!

This is a classic example of not following cable runs, and semi-guessing where they are going and/or coming from....

Because of a loop in the cable from the switch to the shower, I incorrectly identified this as the live from the consumer unit.

When everything was opened up, I discovered my error...

Many thanks for your assistance...

PS. New shower fitted and working fine....

 

[EFLImpudence]

Very good.

Thanks for letting us know.