Earth Rod - Advice please!

[FatAlan]

Why not just get the DNO to provide a TNCS connection? I'm on at TT system and my Ze was too high. DNO came out and connected up to head to give a TNCS connection. I was advised to disconnect the earth rod as it could result in nuisance tripping.

 

[bigspark17]

They may not always provide a pme facility, how could an earth electrode cause nuisance tripping?? This is why DNO opreatives should stay meter side of installations.

 

[Wilko]

Why not just get the DNO to provide a TNCS connection? I'm on at TT system and my Ze was too high. DNO came out and connected up to head to give a TNCS connection. I was advised to disconnect the earth rod as it could result in nuisance tripping.

Hi Alan - just interested in them advising you to bin the rod, how could it cause nuisance tripping do you reckon?

 

[Midwest]

Why not just get the DNO to provide a TNCS connection? I'm on at TT system and my Ze was too high. DNO came out and connected up to head to give a TNCS connection. I was advised to disconnect the earth rod as it could result in nuisance tripping.

Should of left it in, you might be putting it back in a few years time

 

[FatAlan]

Funnily enough I haven't touched the existing rod and have had no problems with any tripping

 

[FatAlan]

Hi Wilko. Wish I'd asked for more info on the nuisance tripping. No explanation was given.

 

[telectrix]

Hi Wilko. Wish I'd asked for more info on the nuisance tripping. No explanation was given.

that's because there isn'one that will hold water.

 

[westward10]

The rod doesn't cause nuisance tripping this is just the earthing facility, nuisance tripping can occur whatever the earthing system.

 

[telectrix]

even if there isn't one.

 

[FatAlan]

Must admit, thinking about it. The only explanation would be that there would have to be an existing very minor fault to earth that prior to connecting to PME was not large enough to trip the RCD. Does that Logic stack up?

 

[telectrix]

no because a RCD (30mA) requires <8k ohms earth leakage to trip. even the worst wet string earth rod would give less than that.

 

[FatAlan]

Ok. So that rules that one out.

 

[HandySparks]

Only situation I can think of is if the original rod was attached to a voltage operated ELCB.

 

[telectrix]

Only situation I can think of is if the original rod was attached to a voltage operated ELCB.

which said elcb should have been binned ages past.

 

[Wilko]

When the DNO earth is in good repair its well below 1 Ohm. So, how keeping a rod in parallel with it could make new trips just doesn't seem plausible. Like you, I'm ahead of the standards with a local special in parallel. I just would have loved to hear his waffle

 

[Dave OCD]

It's obvious, if the rod was sticking out of the ground too much any nuisances who came to your door in the dark could trip over it, so sound advice from the DNO chap !

 

[FatAlan]

To be honest the rod is now situated under a very thorny rose busy and therefore too much of a nusance to remove.

 

[alasdairp]

I'm new to this and just trying to work out how I post a pic.
House is semi-detached in street near to city centre.

I am slightly surprised that near Gloucester city centre the electricity distribution network is not PME (T-N-C-S) with the Earth connection being supplied with the network supply to the house. I wonder if there was a problem with that and the Earth Rod was a dodgy relatively quick fix to lower Ze rather than getting the DNO in to sort their problem. Check if your neighbours all have Earth Rods. If you need one, they will also need one. If they don't have them, then I would ask for a second opinion. You could check with Western Power Distribution on 0845 601 5972 and ask them if your house should need a separate earth rod. If there is a PME system then you should normally not also have an Earth rod as it can lead to stray currents in the network and elevated magnetic fields in your house.

 

[davesparks]

If there is a PME system then you should normally not also have an Earth rod as it can lead to stray currents in the network and elevated magnetic fields in your house.

PME already has an earth rod installed along the distributing main every 40m or less, and at the end of the main. How would an earth rod connected to an installation's MET create a problem that all those other earth rods don't?
Not to mention the bonding of extraneous parts which could be connecting a much bigger earth electrode to the installation.

 

[ppuch1]

in response to the aesthetics of the small "besa" box type Earth Pit (if you can call it that) I am in the process of trying to find a better method and materials for Earth Rod installation, from bigger rod size to the machine man enough to install them in the ground. So far I have only come across two types of Earth pit in this country (not including the Concrete ones) and they are wildly different in size one very good one that is made is normally reserved for commercial installations as its way too big for the purpose of domestic installations (although i have used it previously if space allows) and the other is as already shown in this persons post. Recently It took me 1.5 hours to hammer in an additional 1.2m rod into stony ground in Cornwall (on top of one already in place using a coupling) and this is the norm for most parts here. I must have hit a particularly hard rock but all the same it does beg the question about the health and welfare of Electricians and upper arm/elbow injuries. As for tooling to do the job, i'm not sure if spending £400-500 on a jack hammer that's only used periodically is a good investment. Personally I think the guy did a reasonably good job of the Earth Rod installation as in the picture, maybe we can be more judgmental if we saw some other parts of the rewire.