Ireland Should I have voltage to my earth rod?

[Lignarius]

Hi, I bought a house which I renovated.
I stripped out all wiring, all of it.
new fuse board, 2 rcd, which I set as up stairs and down stairs. I’ve a ring for; sockets up, sockets down, kitchen white goods, kitchen sockets, lights up, lights down and a single cable to the boiler, one to the loft socket and one to the hob. All works no issues. I did work in the garden and had to move the earth rod i had installed. When disconnecting it I got quite a shock. I put the volt meter across it and got 135V ac. So I refitted the rod. Then disconnected it at the fuse board so I could put the volt meter between the rod and the each earth on the board. I got 2V from most but some read 45V, 90V, 50V & 90V (upstairs lights, downstairs lights, white goods, and hob) I killed the board while I reconnected everything then did a last check and now get a steady 35V to the earth rod after it was all off for 5mins. I understand you can have some earth leakage from some appliances but surely something is amis here? I had initially assumed it was a screw through a cable somewhere but it’s coming from 4 different circuits.
Any advice?

 

[telectrix]

The last electrician I paid for left socket on a metal back box hanging suspended in a void behind the electric fire for it to plug in to. He mustn't of had a plastic one to hand or a drill or screws either.

I put in every cable so I know none were pulled or stretched, I made every connection so I could be sure they were all tightened just right, I cut every tail so they are not too short or too long. I spent my childhood being taught to build control panels for factories but seeing as I didn't want to be a sparks I didn't. I have minimal experience in domestic wiring but I'm not a total novice when it comes to making electrical connections.
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I used to have one, seeing as i had no use for it i let it go.

there's always a use for everything. even mothers-in-law.

 

[Risteard]

The installation probably isn't neutralised. Incidentally that is a UK-style DB and not configured to comply with the National Wiring Rules.

 

[davesparks]

I appreciate the risk of disconnecting the earth however I was the only person at risk and was aware of what i was and was not touching.

The logical process was to establish which earth wire was the source of the live voltage, I had anticipated finding 1 then simply testing along the cable till I found the faulty section and then replace it.

Being the only person at risk does not make it any better, that just implies that no one else was there to phone the ambulance when it knocks you out cold.

You clearly were not aware of what you were doing as you did not isolate the installation before disconnecting the earth rod.

That is not a logical fault finding process, that is looking for a fault based on an assumption that a fault is there, but not actually confirming that a fault exists to start with.

 

[snowhead]

there's always a use for everything. even mothers-in-law.

..................Door Stop ??

 

[Lignarius]

The installation probably isn't neutralised. Incidentally that is a UK-style DB and not configured to comply with the National Wiring Rules.

I had wondered if there would be a difference.
Could you clarify what you mean by neutralised?

 

[davesparks]

I had wondered if there would be a difference.
Could you clarify what you mean by neutralised?

Neutralising is one of the basic provisions for electrical safety in the Irish wiring regulations. It is the system by which a TNCS supply has it's PEN referenced to earth on the consumers side of the ownership boundary.

Unfortunately I don't know the details of the requirements to be able to explain it, I only know the general requirement for neutralising, purpose of it and theory behind it.

 

[Risteard]

Neutralising is one of the basic provisions for electrical safety in the Irish wiring regulations. It is the system by which a TNCS supply has it's PEN referenced to earth on the consumers side of the ownership boundary.

Unfortunately I don't know the details of the requirements to be able to explain it, I only know the general requirement for neutralising, purpose of it and theory behind it.

You've done well @davesparks - neutralising is where the DSO's PEN conductor is connected to the MET by the main protective conductor (also referred to as the neutralising link), which is subsequently connected to the Earth electrode via an Earthing conductor.

I've been at two properties in the last fortnight which weren't neutralised - both of them had been that way for years. One of them I was able to rectify as it had a new style cut-out whereby I could connect the conductor. The other had an old internal sealed meter (the DSO used to neutralise at the meter) and therefore required an emergency call to the ESB. They sorted it within a couple of hours after I fitted a main protective conductor ready to connect.

Almost all installations within the State are TN-C-S (although there are a very few TT installations left in rural areas - but practically none. Certainly much less than 1%).

I also don't see any main equipotential bonding present (although it's hard to be sure what's connected to what from a photo of course).

 

[richy3333]

Wow, just wow

 

[Lignarius]

You've done well @davesparks - neutralising is where the DSO's PEN conductor is connected to the MET by the main protective conductor (also referred to as the neutralising link), which is subsequently connected to the Earth electrode via an Earthing conductor.

I've been at two properties in the last fortnight which weren't neutralised - both of them had been that way for years. One of them I was able to rectify as it had a new style cut-out whereby I could connect the conductor. The other had an old internal sealed meter (the DSO used to neutralise at the meter) and therefore required an emergency call to the ESB. They sorted it within a couple of hours after I fitted a main protective conductor ready to connect.

Almost all installations within the State are TN-C-S (although there are a very few TT installations left in rural areas - but practically none. Certainly much less than 1%).

I also don't see any main equipotential bonding present (although it's hard to be sure what's connected to what from a photo of course).

Thanks for getting back to me, obviously this is beyond me but I'd like to understand so I can have it rectified.

Currently the meter only has 2 tails; the Live and the neutral, I have set up the board in the same way as the previous was, the only difference being it was earthed to the plumbing, as all my plumbing, sinks, baths, etc. are all plastic or composite, its also plastic out to the property boundary, I fitted an earth rod. from what you are describing you suggest my supply should be TN-C-S which if I have understood it the DSO neutral doubles as the earth ie the PEN? I do not have a neutralising link between the MET and the neutral or the meter, nor did the previous board which was retrofitted around 25 years ago.

Would this not effectively make the bonded metalwork in a house effectively the same as the neutral? I realise this should not be an issue as it is effectively earth but still.

Is the inclusion of a rod an issue or if it does need a neutralising link does the rod interfere or would it be permissible to retain as an added safety measure.

The Meter is 1956 its all sealed so would need ESB to do anything there. Its an overhead supply.

 

[davesparks]

You've done well @davesparks - neutralising is where the DSO's PEN conductor is connected to the MET by the main protective conductor (also referred to as the neutralising link), which is subsequently connected to the Earth electrode via an Earthing conductor.

I know more than I let on, I just didn't want to post something that leads to the OP having a go at anything else.

 

[Risteard]

I know more than I let on, I just didn't want to post something that leads to the OP having a go at anything else.

Hopefully I've not been too specific with my answer!
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Thanks for getting back to me, obviously this is beyond me but I'd like to understand so I can have it rectified.

Without getting into specifics, the electrode (rod) is mandatory. You MUST have it. It's not optional. But the installation still MUST be neutralised. (Assuming it's not a TT installation - but I can nearly bet my savings that it isn't. TT installations are INCREDIBLY rare within the State and generally are older (or perhaps heritage) installations which haven't been upgraded. That said, even most ancient installations within rural areas (certainly most if not all of Donegal) are TN-C-S.)

I would suggest that you get a REC on board. You can find one on the RECI website at www.reci.ie or www.safeelectric.ie

I presume you are aware of the scope of Restricted Electric Works - it is a criminal offence for these to be carried out by anyone other than a Registered Electrical Contractor (REC).

What part of the country are you in?

 

[Lignarius]

Hopefully I've not been too specific with my answer!
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Without getting into specifics, the electrode (rod) is mandatory. You MUST have it. It's not optional. But the installation still MUST be neutralised. (Assuming it's not a TT installation - but I can nearly bet my savings that it isn't. TT installations are INCREDIBLY rare within the State and generally are older (or perhaps heritage) installations which haven't been upgraded. That said, even most ancient installations within rural areas (certainly most if not all of Donegal) are TN-C-S.)

I would suggest that you get a REC on board. You can find one on the RECI website at www.reci.ie or www.safeelectric.ie

I presume you are aware of the scope of Restricted Electric Works - it is a criminal offence for these to be carried out by anyone other than a Registered Electrical Contractor (REC).

What part of the country are you in?

Hopefully I've not been too specific with my answer!
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Without getting into specifics, the electrode (rod) is mandatory. You MUST have it. It's not optional. But the installation still MUST be neutralised. (Assuming it's not a TT installation - but I can nearly bet my savings that it isn't. TT installations are INCREDIBLY rare within the State and generally are older (or perhaps heritage) installations which haven't been upgraded. That said, even most ancient installations within rural areas (certainly most if not all of Donegal) are TN-C-S.)

I would suggest that you get a REC on board. You can find one on the RECI website at www.reci.ie or www.safeelectric.ie

I presume you are aware of the scope of Restricted Electric Works - it is a criminal offence for these to be carried out by anyone other than a Registered Electrical Contractor (REC).

What part of the country are you in?

Im in west Dublin.

I was planning to get a sparks to test and rectify anything thats needed. As I understood it I thought the legal aspect was limited to tampering with ESB equipment and breaking their seals.

Im from Donegal though, assuming from your post that your up that directIon.

 

[Risteard]

Im in west Dublin.

I was planning to get a sparks to test and rectify anything thats needed. As I understood it I thought the legal aspect was limited to tampering with ESB equipment and breaking their seals.

Im from Donegal though, assuming from your post that your up that directIon.

Yes I'm in Derry, although a significant proportion of my work (if not the majority) is in Donegal. I'm in Limerick today though doing some lighting maintenance for a retail outlet. Cork tomorrow, Dundrum (Dublin) on Friday.

Legally it's not simply tampering with ESB equipment - in fact almost all work within the private home is covered by Restricted Electrical Works. (Visit Electrical Services in Derry & Donegal - Walsh Electrical Services - https://www.walshelectrical.ie/electrical-services.html#restricted-works for further details.)

 

[Lignarius]

Yes I'm in Derry, although a significant proportion of my work (if not the majority) is in Donegal. I'm in Limerick today though doing some lighting maintenance for a retail outlet. Cork tomorrow, Dundrum (Dublin) on Friday.

Legally it's not simply tampering with ESB equipment - in fact almost all work within the private home is covered by Restricted Electrical Works. (Visit Electrical Services in Derry & Donegal - Walsh Electrical Services - https://www.walshelectrical.ie/electrical-services.html#restricted-works for further details.)

wow I’ve just been reading, it’s pretty much any domestic electrical work!
bit late now though!

Regarding immediate risk, the installation is earthed, all metallic components are bonded, the circuits are all fairly simple, connections are all good. I assume it’s safe while I await testing. It’s 9 simple circuits with appropriately sized breakers on 2 RCDs with a 2 pole isolation switch, Aside from neutralising and testing what am I likely to need an REC to do? What kind of cost would I expect to pay?

 

[Scifen]

Always thought my house back home was a TT earthing arrangement and not a TN-C-S didn't know the pen to Earth was on the owner side of installation, does this mean for every TN-C-S in Ireland needs an earth rod installed for neutralizing I always assumed it was a TT because of that. You Learn something new everyday learning this trade.

 

[pc1966]

TT installations are INCREDIBLY rare within the State and generally are older (or perhaps heritage) installations which haven't been upgraded. That said, even most ancient installations within rural areas (certainly most if not all of Donegal) are TN-C-S.)

Out of curiosity, is the TN-C-S more or less mandatory in the republic?

Here you would normally use the DNO (supplier) earth if, as mostly, they provide one. Generally we were mostly TN-S, but moving to TN-C-S whenever systems are replaced, etc. But you could decided you want TT and put in a rod and up-front RCD, etc.

Also do you have any issues with PEN open faults causing outdoor shock risk for car chargers, etc, or is the "every property must have Earth rods" policy doing enough to keep the stray volts down in the event of a DNO cable fault?