OT House electrics, any sparkies on here?
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Hi Guys, I undertand thats it's quite common to have leakage to earth in house electrics, but how much is acceptable?

What is the best way to measure the voltage, between nutural and earth I guess??

Team Racing

We use an ac earth leakage detector for ac circuits, which puts a dc current on the busbar.

From the results you can work out the leakage. Not sure what the acceptable limit is for a house. However, as we have cables running in puddles along a railway I'd expect a house to have almost zero.

If you do measure any, then I'd be isolating each circuit in turb til I found it.

I could probably lend you my tester.

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Quinton is a sparky

Thansk will that may be an option.

I tested it last night bu holding one terminal of the digital volt meter in my hand and the other on the sink (which is earthed) I tried turning off each circuit, each one gave about 3v ac, all together showed about 18v ac

Team Racing

Computers and electronics leak down to earth, so if you have stuff plugged in it will give a false reading, so make sure you have everything unplugged. You should not see any reading at all with everything unplugged, there should be no voltage down to earth, unless there is a fault, or as can happen there's a neutral connected up wrong somewhere if there's still a reading. I've had a slight tingle off some steel conduit on a pub the once removing a box lid, neutral connected up wrong on the circuit :/

The earth leakage circuitbreakers in the Netherlands are rated 30mA anything above that trips the switch and cuts power. (which is quite high as 50mA could kill you easily)
We devellop appliances they need to comply to IEC which has a max of 0.75mA allowed.

Dazed and Confused....

As already said appliances such as computers & cookers will leak to earth. Do you have any RCD's fitted Jim ? If so any leakage above 30mA will trip it anyway.

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As long as it is a 30ma trip! which it should be if your fuseboard is to current regs.

What is the actual problem which your having?

I do have 30ma RCD fitted.

The main problem I'm having is small electric shock when washing up, (stainless sink)
I'm going to add extra earth bonds to the pipes under the sink and earth with a new earth rod outside.

Team Racing

I'll give you a tip jim. Don't pee in the sink until you fix this! lol

If something is worth doing, it's worth doing half of.

thanks John, I knew you loved me, good tip!

Team Racing

What you measured from earth to neutral can be created by electrical items such as fluorescent lights, transformers, computers etc. they connect the neutral and live together directly and can give voltage back on to a neutral.

As above, are you having a specific problem??

what about removing the copper pipes going to the sink and using hep

If your house is wired for PME (protective multiple earth) - and most are nowadays - a lot of what has been said above is incorrect.

Google PME.

On a PME system there will virtually allways be a voltage difference between neutral and true earth.

It shouldn't be as much as you see, but it will allways be there (about 3-7V in my house).

But although you can measure it, you should never feel it as the voltages/currents involved are so low and you should never be feeling neutral to earth anyway because everything you touch should be earth to earth if the house is wired correctly.

There should never be a neutral connection to something you can touch, only ever an earth connection.

Schrödinger's cat - so which one am I ???

as above but earthing to the water pipes is NOT the norm now and has been for many years,

you must have a live which is dicki , isolate lights cooker sockets and find the fault first ...some on in the houses past may have put the fault on ?

i would diconnect the earth from the sink and water pipes and use an earthing spike to ground which you can make and feed the earth to there

The water, gas or oil pipes etc still have to be earthed Steve, within 1 metre of where they enter the premises iirc.

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The main water, main gas and oil [if present] pipes DO need to be bonded.

water is usually earthed using 10mm just after the stopcock and before the first join.
gas should be eathed again using 10mm and this is usually done inside the gas meter box.

However theres no need to have bond the main water if the main water supply is coming up in hep.


So firstly, if your main water pipe isn't bonded thats what you want to do, run a 10mm earth from the consumer unit to just after the stop cock and earth it using a bonding clamp on the pipe. If the gas isn't done then it might be worth doing that also.
Then you want to do some supplementry bonding. Which is basically where all the pipes come into the boiler you want to put a bonding clamp on each pipe, and run some 10mm earth linked to each pipe.
It's good practice to not cut the cable and use one continuous length when bonding all the pipes. now by doing this supplementy bonding your earthing every pipe in the house and having them at the same equipotential.


or your problem could lie with something as simple as recieving a static shock from sink from walking across the floor.

Edited by jamestar on 10th Nov, 2011.

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speed didn't kill me, but taxation probably will

Ive seen it where a farm with poor electrics in its outbuildings has leaked voltage into the ground which has then been picked up by a property 300m up the road and shown as voltage on the earth..took a while find that one!

right phil, jimster just bond everthing in the house .....lol door knobs included ....lol

Dont suppose you have had a new boiler recently? Im not saying this is happening in your case but I have seen this exact thing happen when systems get rid of the hot water cylinder-you loose the only water system earth which is through the immersion heater, if there is no cross bonding and a break in the cold water pipework from the main bond then what you descibe has happened-36v on the sink as i recall.

Another more important point is rather than trying to mask a possible fault why not try to see if there is one in the first place, dont know if you have any mates in the trade-a sparky with some calibrated test gear would be able to do, among other things, an insulation resistance test on your wiring to check its integrity and find a possible 'leak', an earth fault loop impendance test see what shape the main earth path is in, and an rcd test to make sure your rcd is actually working, the test button on the front is not always a perfect indication of correct operation.

Could be from an non rcd protected circuit -you dont mention where the rcd is, is everything on one main incommer rcd, a 16th edition board with only some circuits on the rcd or a new 17th board with everything on 2 split ones?

As above Pme or tncs as we learnt it is all well and good if thats what you have at your home but irrelevant if your on say a tt system, dont suppose your on overhead lines by any chance?

perhaps some investigation is in order

ta

oli

Edited by oli79 on 11th Nov, 2011.

On 5th Oct, 2014 Shauna said:
What that's crazy, you go commando hahaha! How heavy is your helmet ?

^ was any of that english?

I got as far as "don't suppose" lol.

My opinion with electric is leave it to the pro's

If something is worth doing, it's worth doing half of.