Mild tingle off of shower mixer tap.

[robopenshaw]

So I've condemned my shower on first test drive!

When in the shower you can just feel a very mild tingle off of the metal mixer tap... It doesn't take a genius to work out that this is very very BAD!

So time for a sparky really...

But here are my questions anyway...

Currently there is no earth bonding on the pipes that exit the pump. I have the straps and am going to do it tonight... So the pipes leaving the pump are currently totally un-earthed as the pump and flexi hoses are plastic....
My concern is that there is sufficient potential there to be able to feel the tingle, with earthing it will not be noticeable, but my concern is it's there at all! This can't be normal surely?

So I've started doubting if the earthing to the ring main supplying the airing cupboard socket is connected at the CU end...

Before a sparky turns up (I want one to quote for the change of fuse wire based CU unit to an MCB RCD CU anyway!) What can I do to check the earth wire I have connected to the pump is actually earthed! (short of taking the front off the CU and looking where the ring main enters the CU, I don't want to get anywhere near mains I can't isolate!)

Cheers
Rob

 

[robopenshaw]

PS. Is it possibly coupling to earth of live via filters/noise suppression /something inside the pump? I know PC power supplies can leak a little current onto the earth?????

Cheers
Rob

 

[JohnD]

You need to Supplementary Bond all the metal pipes that enter the bathroom. That'll be the hot and cold water pipes, the central heating pipes, and, if you have lead or cast iron waste or soil pipes, them too. Generally if you bond to them when they first enter the bathroom, you do not need to bond the same pipe a second time, as there is nothing that can introduce a potential to it afterwards. However with your shower pump, bond to the pipes in and out of it as well. edited: since I see from the related post you put up on Monday that the shower pump insulates the in/out pipes, thus interupting the initial bonding, and is an electrical device that might possibly introduce a potential //www.diynot.com/forums/viewtopic.php?p=456218&highlight=#456218[/i]


Then bond to the earth wire of every circuit that enters the bathroom. That'll be the shower pump, the light switch, possibly the immersion heater. You probably haven't got an electric heater in there, and the shaver socket, if present, is probably run off the lighting circuit. Otherwise bond to the earth wire of them too.

What this will do is put all the pipes at the same potential, so preventing you getting a shock from touching (e.g.) the radiator with one hand and the tap with the other, or sitting on the bath while touching something else.

This is irrespective of any fault correction on the shower pump. Which it sounds as if you have got. Perhaps it is faulty or incorrectly connected. However there may be some other electrical fault causing it. For example the immersion heater might have a current leakage that is travelling through the hot pipes.

The electrician you call to fault-find can do the supplementary bonding as well but it is an easy DIY job.

You could use a Socket Tester to see if your ring has an earth connection, but they are very inaccurate and will not tell you how good it is - for example if it is high-resistance.

Have you stopped using the shower pump, and turned off its electrical supply, or are you planning to carry on getting electric shocks in your bathroom?

 

[robopenshaw]

Firstly thanks for your reply!

No no no no... It's off! It's staying off until I find out and make it safe... Through either a paid for sparky or myself, but I would have to be very happy that I have fixed the problem! I'm pretty sure the source fo the electricity is the pump as it disappears if I trip the RCD to the pump with the test switch, but leave the shower running.....

I totally agree on the supplementary bonding, and it will be done. I'm concerned that there may be NO bonding currently in the bathroom at all! But I am more concerned that there is something that neads earthing away fromt eh pipes to start with!(Bought the house a month ago, so still discovering the DIY bodges byt the looks of things!)

Until I installed the shower, the ONLY electrical source in the bathroom was the ceiling light. Now there is a shower pump in the mix. (Sited in the airing cupboard, but potentially electrically connected to the mixer tap in the bathroom via copper pipes!)

I am sure the spur and pump is correctly wired up, (L, N and Earth!) but I'm concerned over either a faulty pump or a possible earth problem on that ring main. (I'm not sure if pumps typically could induce a small bit of leakage ontot eh earth, which is normally safely carried away to earth in a fault free system, i.e. the earth ont eh ring is connected....)

The immersian heater is unplugged and off! So it's not that! (Yes it actually has a plug on it which is horrendous so far as I am concerned... I have used it once, and the plug actually get's quite warm too the touch, so that aint getting used any more either until I sort that out aswell (or a sparky!))

The plug socket in the airing cupboard(near the immersian heater) appreas to be on it's own ring main possibly a ring main purely for the immersion heater, so why they put it a plug and socket on it I don't have a clue! Sounds very dodgy to me! And I'd hard wire that to eventually with an FCU once I know the curent draw of it and know the wiring is capable of supporting it!

 

[JohnD]

It is usual for an immersion heater to have its own dedicated radial circuit (nothing else on it) fused at 15A or 16A at the consumer unit. In which case it does not need a fused plug or an FCU, just a 20A DP switch (pref with neon) labelled "Immersion Heater"

It is preferable not to have a socket adjacent to the bathroom as it encourages people to take in appliances like hair dryers, TVs, electric heaters, toasters etc.

 

[robopenshaw]

Is it ok to have a plug on it? The airing cupboard isn't directly outside the bathroom, it's also across the landing and the socket is inside the cupboard.

But the plug on the immersion heater does get rather warm to the touch! I will eventually replace for a DP 20A switch as you recommend.... I'm pretty sure it's a 3.5kw immersion (~15A?) so I guess it's a little heavy for a 13Amp plug and socket, so best changed...

I am awaiting a call back from an electrician regarding getting an electrical inspection carried out of the CU, earths and probably my shower install too. I've been told to expect ~£150 all in, with a quote to replace the fuse board (fuse wire) with a RCD BCD CU.... (Also looking to have a new ring main installed around the kitchen... possibly.... as I beleive we only have 3 rings, lights, sockets, immersion, and currently 3 fuses only)

Cheers
Rob

 

[JohnD]

The plug is not correct, and should be replaced by a DP switch, as you say. As defects go, it is not one of the worst ones, but it is easy to correct..

Ask your electrician if he is a member of a Self Certification Scheme, and which one (if not, electrical work to your Kitchen, Bathroom and CU will have to be notified to, and inspected by, your local council building Control, which is extra trouble and expense - though this does not apply to the Earthing and Bonding).

 

[robopenshaw]

Thats great!

Thanks for all your help with that!

With regards the shower installation, now that I have earth sleaving for the bare earth in twin and earth, I'm re-opening all the "box's" and putting the sleaving on the bare earth wires.... (Was too dodgy to leave em and particularly smacked of a bodge to me when I did it, even though I was careful to ensure no shorts to earth....)

Thanks again for all your replys I'll take all your advice and carry out the earth bonding tonight with the electrician booked to come remedy the other issues I'm not comfortable doing myself! Good point on the self certification, I'll check!

Cheers
Rob

 

[robopenshaw]

Add all my supplimentary earth bonding... Opened all teh FCU's and put my earth sleaving over the bare earth cores...

The tingle has vanished and the RCD isn't tripping. SO I am goign to assume all is fine!

THe electritian is still booked to come an just carry out a suplimentary electrical check and also quote for the work of changing our fuse board for a new modern CU.... (RCD's and BCD's here we come!)


Thanks for your patient replies to my mad ramblings and questioning! I'm a happy chappie now....

Rob