Neutral to earth voltage

istabraq

230 volts between neutral and earth and arcing on earth wires when supply turned off .Any ideas?

random.stranger

istabraq wrote: »

230 volts between neutral and earth and arcing on earth wires when supply turned off .Any ideas?

What's your neutral-live voltage?

davelerave

check at the supply intake point anyhow.or is it just a prob with a circuit?.

istabraq

live to neutral voltage is 230.The problem seems to be only on one circuit

random.stranger

istabraq wrote: »

live to neutral voltage is 230.The problem seems to be only on one circuit

When you say "one circuit" are you talking about one circuit in the fuse box in your house? Did you use a phase tester to check if it was your neutral or earth that was live?

2011

Measure the voltage between neutral and earth and live and earth.

I think you will see 230 volts between neutral and earth and 0 volts between live and earth.

This would simply mean that somewhere in the circuit someone has used the blue cable as the live and the brown as a neutral. This may be at the board or at some onther point.

What type of circuit is it, lighting, sockets???

random.stranger

Yep, I was thinking along the same lines 2011.

davelerave

a L-N swop would give 230v blue/black-earth but not a fault current(arcing) in itself.a N-E swop (at a fitting or joint) or a fault on a non-rcd protected circuit would cause a fault current and voltage on (separated?) earths to neutral.or a fault current on a badly earthed system/circuit might show a voltage between N-E .is the fault current(arcing) from another circuit?try to isolate it

bertie1

istabraq wrote: »

230 volts between neutral and earth and arcing on earth wires when supply turned off .Any ideas?

Sounds like a broken neutral. you see it happening when a neutral is switched ( which it should not be ) . If the cables to a light circuit were reversed at the board, the neutral would be switched.

istabraq

Spot on 2011 neutral to earth 230v.Live to earth 0v but this still doesn't explain the arcing on the earths when the supply is turned off.by the way it is a circuit for a submersible pump.

davelerave

if you've confirmed reverse polarity (with a phase tester).isolate the source of leakage current by switching off(mcbs etc).is the installation neutralized?

2011

Spot on 2011 neutral to earth 230v.Live to earth 0v

Ok that is 1 issue resloved.

but this still doesn't explain the arcing on the earths when the supply is turned off

This is a seperate issue. I am not too clear what you mean here.

Are there disconnected earth wires and when you touch them off each other there is a sprak?? When does the arching occur??

istabraq

The installation is not neutralized.The arcing occurs when breaking the earths

davelerave

did you confirm polarity originally.?if it's a direct earthed system the pump might be earthing the installation .when you split them is the 'incoming' earth from m.e.t. live? or the other way round.you would need to eliminate any fault currents and put down a decent rod anyhow for 'tt'.changing to t-n-cs( if possible)would be a bigger job .depends.

istabraq

Polarity confirmed.Will check earths and get back to you on this .Thanks

2011

The installation is not neutralized

Are you sure?? This is normally (not always) done at the ESB meter.

TT systems (not neutralised) are quite rare in Ireland. They are only found in rural areas only AFAIK. Under normal operating conditions I would not expect an earth current to flow that would be large enough to cause arching.

I take it that there is no RCD fitted on this circuit??

I think you should get a sparks to look at this.

davelerave

they're about .but as you say it might need a re-wire or partial re-wire if it's domestic.regardless of the pump problem.fault current if that's what it is would be low alright.there can be a lot of variables with these problems anyhow.might be something completely different

random.stranger

istabraq wrote: »

Spot on 2011 neutral to earth 230v.Live to earth 0v but this still doesn't explain the arcing on the earths when the supply is turned off.by the way it is a circuit for a submersible pump.

I don't think the arcing is a fault. The motor in your pump is equivalent to an inductor & when you turn it off I would expect to see arcing.

2011

they're about

Yes, but not many.

there can be a lot of variables with these problems anyhow.might be something completely different

True.

I don't think the arcing is a fault

If you break an earth cable that feeds a small load (like a single phase pump) and it arcs I would think the chances are that there is a problem.

It is hard to say much more without seeing and testing it.

2011

that's on the supply not the earth

Perhaps I am not understanding this correctly.

What I thought the OP was saying is that when the earth is disconnected and then reconnected it arcs. In that case there is a problem.

If there is arcing happening between live and earth after the pump is switched off then I would not be so concerned. Apoligies if this is the case.

davelerave

2011 wrote: »

Perhaps I am not understanding this correctly.

What I thought the OP was saying is that when the earth is disconnected and then reconnected it arcs. In that case there is a problem.

If there is arcing happening between live and earth after the pump is switched off then I would not be so concerned. Apoligies if this is the case.

sorry there i deleted that post .i was pointing out that any arcing from switching the inductive load would be on the L and N poles.
He has confirmed reverse polarity and no neutralizing .earths are arcing with supply off(mcb?)so there seems to be a earth fault current from somewere.if this supply(earth) is looped on somewhere it might be a return fault current from another circuit or maybe the met is earthed through the pump .hard to be definite anyway i'm only guessing but will have to find out now

istabraq

This may help or confuse ye more.The circuit is protected by an old type rcd which tripped.With the rcd tripped if i try to seperate the earths this is when the arcing occurs when rcd is reset there is know arcing on the earths. The circuit is a loop on from another circuit so what you are saying Davelerave could be right . I will be having another look at this tommorow so i will let ye know.

davelerave

well. keep in mind the 'bigger picture' anyway.installation prob needs a major overhaul.sounds like dodgy neutralizing maybe on the rcd side. earth fault current from a non-rcd circuit might be diverted to met or ground when rcd trips causing sparking

2011

The RCD is tripping due to a fault to earth. This is either a live to earth fault or a neutral to earth fault. This needs attention. The chances are this is due to a leak. In other words the RCD is doing its job. You may find that replecing the pump solves everything.

I think it is time for you to call an electrician!

bushy...

Just two things i've seen before :

If the neutral is not tied to the earth ,
and the earth in the house isn't connected to an earth rod or something
your PC might drag the earth up - seen it with an old PC and an extension with "no" earth.

Some submersible pumps have temperature monitoring etc built in , communicates over the power cable . If the L & N gets mixed up the monitor can die , but the pump itself will work away.

random.stranger

Is this a new pump that you're wiring (if so, what's it's wattage). Or a pump that has been happily working away for years & now started throwing up problems?

hey_hey

I have came across a problem like this before. There was no potential difference between live and earth and i was getting 230v between earth and neutral and live and neutral. The problem with the arcing may be because your connecting a damaged earth wire that has voltage on it to an earth wire which is properly earthed and at zero volts. get a phase tester and hold it on the earth that has voltage on it, then with you phase teater still touching the bad earth join the other (good) earth to it, the voltage should dissapear...But beware!!! the voltage is just making its way back through the earth then down to your earth rod.... this may seem ok but if by chance somebody dug up the earth rod or even dissconnected it from the earth bar it will mean the fault voltage will just go straight to the earth bar and make everything that is earthed in your house live!!!! I eventually found that a socket screw had cut through the live in the back-box creating a short....fuse never tripped!!

istabraq

Traced main earth and found very bad connection at the earth rod.I also ran a seperate circuit for the pump.Problem resolved.Thanks for all the help

Stevieo21

Hi I’m getting 27v between neutral and earth
I disconnected the earths one by one at the board and the main earth was arcing
I’m getting 27v when the rcb is off
I traced it back to one circuit and disconnected it in board
I’m still getting voltage at the disconnected cables in the board

meercat

Stevieo21 wrote: »

Hi I’m getting 27v between neutral and earth
I disconnected the earths one by one at the board and the main earth was arcing
I’m getting 27v when the rcb is off
I traced it back to one circuit and disconnected it in board
I’m still getting voltage at the disconnected cables in the board

Do an earth loop impedance test
Check and verify neutralised earth link at esbn cutout

Stevieo21

meercat wrote: »

Do an earth loop impedance test
Check and verify neutralised earth link at esbn cutout

Hi
I did the earth loop impedance test it was .48
I checked for neautralised earth link at meter and it’s there
New smart meter fitted with isolator switch

Stevieo21

meercat wrote: »

Do an earth loop impedance test
Check and verify neutralised earth link at esbn cutout

Hi
I did the earth loop impedance test it was .48
I checked for neautralised earth link at meter and it’s there
New smart meter fitted with isolator switch

meercat

Stevieo21 wrote: »

Hi I’m getting 27v between neutral and earth
I disconnected the earths one by one at the board and the main earth was arcing
I’m getting 27v when the rcb is off
I traced it back to one circuit and disconnected it in board
I’m still getting voltage at the disconnected cables in the board

1 Are you getting 27v on all circuits
2 Where are you reading this voltage
3 Have you checked the equipotential bonding
4 When you say you’ve traced it back to one circuit and disconnected it at the board,is the main board still showing 27v
5 Is this a rural installation
6 Can you do a loop test next door (it’s possible the main neutral is burnt out)