Electric Shower - No Voltage

[Toki]

I've been trying to help a friend with their electric shower but cannot find the solution to the electric shower not working.

I started with the fuse which was fine. Next I looked at the shower unit and there was only 5V on the supply side of the shower. Next I tried the shower pull switch and found 5V on both the supply and the shower side. I next removed the pull switch from the circuit and found the switch was going from open to close ( 0 ohms) when pulled.

Withe the switch removed the supply side was still only giving 5V for some reason. I traced the supply as best I could in the loft, there was 1 round junction box, again 5V on each side and as far as I can see that goes down and in tot the junction box. Any ideas?

Any questions please ask. The multiple meter is working fine.

Thanks in advance.

 

[flyingsparks]

Have you checked the voltage on the outgoing side of the fuse / MCB? Could be a faulty MCB or is there perhaps an RCD tripped?

 

[Toki]

It's a fuse box, not RCD. the fuse is fine, short between 2 sides. I can't get the probes in to check the voltage at the fuse though.

 

[PrenticeBoyofDerry]

When tested for voltage, did you test live-neutral, neutral-earth and earth to live? If not I suggest you do that?

 

[Toki]

I did try voltage between live/neutral and earth. I do recall checking between live OR Neutral and earth. Not 100% sure I checked both though. I'll check tomorrow. I take it this would check for a fault in the cable to earth?

Thanks.

 

[PrenticeBoyofDerry]

It could give us clues to which conductor is out, but it maybe a case of doing some continuity tests also. I suspect you have neutral out, but you would then still get 230-250V between line and earth, so we need to know that result, but it could be also possible that you have earth out, which means continuity tests required. So if you have both neutral and earth out, the line conductor could be live, which would be potentially dangerous as you think it is dead.

 

[Toki]

Great thanks, I'll post the results tomorrow night.

 

[PrenticeBoyofDerry]

Great thanks, I'll post the results tomorrow night.

I will look out for them

 

[Toki]

I checked the voltage as you mentioned. Getting 5V between live/neutral and live/earth. 0V between neutral/earth. This was regardless of if the fuse was in or out.

I then opened the fuse box and found the connecting with to the shower fuse to be burnt from the fuse upwards for approx 4 inches. There is also something metal lying below the fuse that looks like it has come off and may have caused a short burning the cable. Strange why the fuse never went though. I'm going to leave it to someone more qualified than me to resolve now.

Thanks for your help.

 

[AndyPRK]

A pic would of been nice.

 

[flyingsparks]

I'm going to leave it to someone more qualified than me to resolve now.

Thanks for your help.

Glad to hear when someone knows they are out of their depth and knows it's time to seek expert help. Unlike so many other people we see on this forum all to often..

 

[Toki]

I've uploaded pics to my album if you know how to look there?

 

[EFLImpudence]

Untitled

• Toki
• 15 Jul 2014
• 1

Untitled

• Toki
• 15 Jul 2014
• 1

 

[PrenticeBoyofDerry]

looks like either the terminal in the fuse holder has come loose and burnt out through arking or the same has been caused by loose conductor or a bit of both. You will at best require new fuseholder and the cable making good.

 

[RF Lighting]

You'll be needing more than a fuseholder.

You need a replacement CU.

That looped feed from the incommer with the slashed sheath looks "interesting"