Help! Never seen this before!

[Steve93]

I am installing solar to a house and this is there main incoming. I can’t see an Earth anywhere but test ZS across L-N coming out at 0.20. Then with gas bond disconnected is 0.38! But we only have gas bonding. No other earth anywhere. Anyone had this?

 

[SparkyChick]

You say Zs across L-N...

What about the true Ze or Zdb?

Could be someone had converted it to TNCS without DNO.

What about a pic of the main earth terminal in the cu? And a wider shot showing all the incoming gear.

 

[Pete999]

I am installing solar to a house and this is there main incoming. I can’t see an Earth anywhere but test ZS across L-N coming out at 0.20. Then with gas bond disconnected is 0.38! But we only have gas bonding. No other earth anywhere. Anyone had this?

View attachment 44800

View attachment 44801

Top right hand side of Pic DP MCB with TWECC coming out at the bottom, looks damaged to me where it bends into the enclosure, or do I need to go to Specsavers?

 

[Steve93]

You say Zs across L-N...

What about the true Ze or Zdb?

Could be someone had converted it to TNCS without DNO.

What about a pic of the main earth terminal in the cu? And a wider shot showing all the incoming gear.

Sorry zdb is what I ment. Here is a full pic and there is no main earth terminal. The 6’m gas bond goes from db to the gas meter. There are a couple of dbs that there earths go back to this ‘main’ db. But this main db only has gas bond earth in it. Nothing else

 

[Andy78]

Top right hand side of Pic DP MCB with TWECC coming out at the bottom, looks damaged to me where it bends into the enclosure, or do I need to go to Specsavers?

It's a burry pic but I think that's a 100A DP isolator with red/black T&E passing through brown/blue shrouds of some sort.

 

[Pete999]

Sorry zdb is what I ment. Here is a full pic and there is no main earth terminal. The 6’m gas bond goes from db to the gas meter. There are a couple of dbs that there earths go back to this ‘main’ db. But this main db only has gas bond earth in it. Nothing else

View attachment 44802

View attachment 44803

Wassat blue jobby mid righhand of piccy?

 

[telectrix]

Top right hand side of Pic DP MCB with TWECC coming out at the bottom, looks damaged to me where it bends into the enclosure, or do I need to go to Specsavers?

looks like some cowboy has taken a T/E feed from that D/P switch and split the cores.

 

[Steve93]

It's a burry pic but I think that's a 100A DP isolator with red/black T&E passing through brown/blue shrouds of some sort.

Yes that’s right which was done by meter fitter. This could be a multitude of problems. But atm I neee to find an earth

 

[Pete999]

looks like some cowboy has taken a T/E feed from that D/P switch and split the cores.

Yes me also, wasn't sure

 

[Steve93]

Wassat blue jobby mid righhand of piccy?

That’s my new db I’m installing for solar taken the neutral out to drill hole for main tails.

 

[Pete999]

An earth rod outside direct to CU earthbar?

 

[Steve93]

An earth rod outside direct to CU earthbar?

Can’t see how tho as there is one 6mm earth in db which is gas bond

 

[Andy78]

Can’t see how tho as there is one 6mm earth in db which is gas bond

Could be a much smaller cable to the rod. Readings you are getting would not make me think rod though.

Supp bonding from cpc to pipework that is shared with next door's pipework that is bonded and connected to their PME ?

 

[Steve93]

Could be a much smaller cable to the rod. Readings you are getting would not make me think rod though.

Supp bonding from cpc to pipework that is shared with next door's pipework that is bonded and connected to their PME ?

It’s a old detached house which is a fair few meters away from neighbour. I am stumped atm

 

[Nigel]

Top right hand side of Pic DP MCB with TWECC coming out at the bottom, looks damaged to me where it bends into the enclosure, or do I need to go to Specsavers?

It is not a DP MCB and it is not what the op asked for help on......

 

[Nigel]

It’s a old detached house which is a fair few meters away from neighbour. I am stumped atm

So with the gas bond removed there is no other earths connected to the CU earth bar apart from the final circuit earths?

 

[Steve93]

Not that I can see no

 

[Nigel]

Not that I can see no

Surely you can see the whole of the earth bar? Is there another earth or not? Your answer seems unsure so just need to clarify.

 

[Steve93]

So with the gas bond removed there is no other earths connected to the CU earth bar apart from the final circuit earths?

Sorry that’s correct yes

 

[Steve93]

Surely you can see the whole of the earth bar? Is there another earth or not? Your answer seems unsure so just need to clarify.

There is no other earths

 

[Octopus]

Old properties often have earth's from random sockets to the incoming water ....

 

[Steve93]

Old properties often have earth's from random sockets to the incoming water ....

As I can’t find an Earth would you suggest earth rod? Although this zs at db reading is so low

 

[Nigel]

I think you need to disconnect earths one at a time and see how the Ze fluctuates and hopefully when you remove one the results will go up massively. This should then point you in the right direction to where the the earth is currently coming from.

I would not resort to an earth rod yet until you get to the bottom of the where the earth is coming from currently.

 

[davesparks]

That is a lead sheathed cable coming in which should be connected to the ISCO sealing chamber and other ISCO boxes.

Inspect and test the cover of the sealing chamber to see if it is connected to the lead sheath and then test it to see if it gives a good Ze.

 

[Steve93]

Just t

That is a lead sheathed cable coming in which should be connected to the ISCO sealing chamber and other ISCO boxes.

Inspect and test the cover of the sealing chamber to see if it is connected to the lead sheath and then test it to see if it gives a good Ze.

just tried that and it wouldn’t pick an Earth up from the casing

 

[davesparks]

Just t

just tried that and it wouldn’t pick an Earth up from the casing

That’s not good, I’d suggest speaking to the DNO, they like to replace cast iron cutouts

 

[davesparks]

This is a page from the 1940 WT Henley jointing manual showing how to install these cutouts. You can see the earthing wire which should connect to the screws on the top of the cutouts and front of the sealing chamber.

 

[Lucien Nunes]

Steve93, I agree with the others about checking the present earthing config although you might find it has been relying on the gas bond, and anything else providing a bit of continuity is purely by luck. The service cable almost certainly has a good earth on its sheath although it doesn't look like it was made off.

But what interests me is that ISCo service head. That was probably a 3-wire DC service originally, pos and neg lines with separate cutouts (in this case each with two fuses) and a neutral. These are very scarce now and if the DNO are called to replace it, I will happily send you some loot to give them a drink to leave it behind, and ship it to us for the museum. Please give me a shout if you go down that route!

 

[Steve93]

DNO don’t seem to care! They bassicly told me to put it on a TT system. They can send someone out to see if it can be changed to PME but that’s a 5 week waiting time.

 

[telectrix]

DNO don’t seem to care! They bassicly told me to put it on a TT system. They can send someone out to see if it can be changed to PME but that’s a 5 week waiting time.

DNO coming on a slow boat from China? that lead time is a disgrace.

 

[Pete999]

A pic of the gubbins in the CU might help!

 

[Deleted account]

What about a pic of the main earth terminal in the cu.

Still waiting for that pic....

 

[telectrix]

A pic of the gubbins in the CU might help!

wayayy too technical as it's way past beer o'clock.

 

[Pete999]

Still waiting for that pic....

Yeah whats's apnin OP get a grip will you

 

[Steve93]

I’ve explained. There are final circuits and one 6mm which goes to the gas bond only! Nothing else no main earth nothing. Just the earths from the circuits

 

[Deleted account]

Is the consumer unit metal. Is that bonded to earth via the casing. Need photos.

 

[DPG]

Not sure if anyone has thought of it, but we could do with photos.

 

[Pete999]

Not sure if anyone has thought of it, but we could do with photos.

Keep up Mate please

 

[Steve93]

It’s an old domino db. Plastic. I’m off site now and couldn’t keep turning power off to take pics inside.

 

[davesparks]

DNO don’t seem to care! They bassicly told me to put it on a TT system. They can send someone out to see if it can be changed to PME but that’s a 5 week waiting time.

Did you explain to them that there’s an unearthed cast iron cutout with open holes in the top exposing live parts?
The TT/PME answer sounds more like the standard response to asking for an earth connection rather than reporting this situation.

 

[Octopus]

Maybe seek the advice of your boss - I see you have trainee access.

 

[buzzlightyear]

the op needs to get DNO in to have a look at it ,if he is in doubt.
test at the cu and test for a earth on old DNO isolators . what's the betting their is a earth some where .ring up Scottish and south Elecs.

 

[b-spark]

I've seen it before, inside the cast iron isolators theirs a rewireable fuse, what your seeing is a split supply for another building aswell as yours. Back in the 50's it was also acceptable to use the gas as the earth. The meter fitter wants reporting, but it is upto the electrician to give a earth. is it a rural location?

 

[Steve93]

Did you explain to them that there’s an unearthed cast iron cutout with open holes in the top exposing live parts?
The TT/PME answer sounds more like the standard response to asking for an earth connection rather than reporting this situation.

Yes explained clear as day she just put me on hold and then went on to say they can send someone out in 5 weeks.

 

[Steve93]

Maybe seek the advice of your boss - I see you have trainee access.

Yes but something I’d rather find out for myself. He is well aware but I like to look into these things so I know for future reference etc.

 

[Steve93]

I've seen it before, inside the cast iron isolators theirs a rewireable fuse, what your seeing is a split supply for another building aswell as yours. Back in the 50's it was also acceptable to use the gas as the earth. The meter fitter wants reporting, but it is upto the electrician to give a earth. is it a rural location?

If that’s the case how come I can’t get any earth reading off the casing?

 

[buzzlightyear]

Yes explained clear as day she just put me on hold and then went on to say they can send someone out in 5 weeks.

tell them that you will wait a couple of months if they want .

 

[buzzlightyear]

Yes explained clear as day she just put me on hold and then went on to say they can send someone out in 5 weeks.

tell them that you will wait a couple of months if they want .

 

[Octopus]

Yes but something I’d rather find out for myself. He is well aware but I like to look into these things so I know for future reference etc.

I've given you a disagree because learning from experienced sparks is what a boss is for............

 

[Steve93]

I've seen it before, inside the cast iron isolators theirs a rewireable fuse, what your seeing is a split supply for another building aswell as yours. Back in the 50's it was also acceptable to use the gas as the earth. The meter fitter wants reporting, but it is upto the electrician to give a earth. is it a rural location?

If that’s the case how come I can’t get any earth reading off the casing?