Eicr

[joehat]

So the guidelines are to test,inspect 100% of bonding, if you see bonding in cu but can't see to test, just been to one and it was under the floor, would u class this as satisfactory or unsatisfactory, or just put at n/v and limitation?

 

[Octopus]

Did you do a continuity test?

 

[joehat]

Did you do a continuity test?

Yes but it was 1.56ohms and I think the bonding is under the floor, so I did it on the nearest incoming tap, what would you do?

 

[Octopus]

Yes but it was 1.56ohms and I think the bonding is under the floor, so I did it on the nearest incoming tap, what would you do?

hum... continuity is 1.56 ohms, suggest a C2 then

 

[davesparks]

Yes but it was 1.56ohms and I think the bonding is under the floor, so I did it on the nearest incoming tap, what would you do?

You need to make an assessment of whether that is acceptable or not.
Is the bonding connection accessible? Is the impedance you measured right for the estimated length of the bonding conductor? Does the pipe work test out as an extraneous part? Did you disconnect all parallel paths before testing?

 

[joehat]

You need to make an assessment of whether that is acceptable or not.
Is the bonding connection accessible? Is the impedance you measured right for the estimated length of the bonding conductor? Does the pipe work test out as an extraneous part? Did you disconnect all parallel paths before testing?

Theirs no specified max, just as low as possible!!

I've had one install where the put s plastic fitting after the incoming water pipe

 

[davesparks]

Theirs no specified max, just as low as possible!!

I've had one install where the put s plastic fitting after the incoming water pipe

I never said there was, but it's easy enough to work out roughly what it should be for estimated length of the bonding conductor.

What has the plastic fitting got to do with it?

 

[Flanders]

1.56 sounds like a parallel earth path to me probley from the boiler or emersion heater

 

[HappyHippyDad]

I think this is a good question. What is a good figure? This question has been asked before and the answer is their isn't a given figure. I don't see how you can 'estimate' a length for the bonding if you can't find the incoming water supply. If you can then that's a different matter and you could then estimate from the known resistance figures for a 10mm conductor. But if you could see where it enters the house in order to make an estimate then you'd be able to test to see anyway if adequately bonded by using the 0.05ohms suggestion in GN8 (measuring between known earth and pipe), so I'm guessing Jo can't find where it comes in?

If you can't find the stopcock or where the water enters the house and can't find the bonding, then I would put it down as further investigation required as its a pretty important aspect to put down as NV.

 

[davesparks]

I think this is a good question. What is a good figure? This question has been asked before and the answer is their isn't a given figure. I don't see how you can 'estimate' a length for the bonding if you can't find the incoming water supply. If you can then that's a different matter and you could then estimate from the known resistance figures for a 10mm conductor. But if you could see where it enters the house in order to make an estimate then you'd be able to test to see anyway if adequately bonded by using the 0.05ohms suggestion in GN8 (measuring between known earth and pipe), so I'm guessing Jo can't find where it comes in?

If you can't find the stopcock or where the water enters the house and can't find the bonding, then I would put it down as further investigation required as its a pretty important aspect to put down as NV.

You can have a pretty good idea of how long a cable would need to be to get from the CU to the furthest corner of a house and use that as a basis. Or just say that a 50m run would be around 0.1ohms so anything much more than that is likely to not be a main bond.
The 0.05 ohm suggestion in gn8 is between the bonding clamp terminal and the pipe being bonded, not between a known earth and a pipe.

You are right it's an important thing to not verify, and in a house there is very little excuse not to look for it. There's not that many different places where you can hide a stopcock in a house!

 

[NDG Elecs]

There's not that many different places where you can hide a stopcock in a house!

I wish you were 100% right there Dave!! I've had a right couple of pigs in the last five years..

A 25m long bonding conductor should be approx 0.08 for 6mm and 0.05 for 10mm....a 25m run would cover a lot of domestic properties quite easily. Get those leads zeroed!! And get past any oxidation on the pipework if you can't see the 951 clamp. 1.56 ohms on a 'normal' sized house sounds like a parallel path to me. I got 0.19 ohms through approx 4m of gas pipework recently. The existing main bond had been cut and pulled out of the wall when I was renewing it.

 

[Flanders]

I wish you were 100% right there Dave!! I've had a right couple of pigs in the last five years..

A 25m long bonding conductor should be approx 0.08 for 6mm and 0.05 for 10mm....a 25m run would cover a lot of domestic properties quite easily. Get those leads zeroed!! And get past any oxidation on the pipework if you can't see the 951 clamp. 1.56 ohms on a 'normal' sized house sounds like a parallel path to me. I got 0.19 ohms through approx 4m of gas pipework recently. The existing main bond had been cut and pulled out of the wall when I was renewing it.

SNAP (post 8):yes:

 

[Octopus]

Thing is that this is an EICR. I would give it a C2 and FI on the report. Send invoice and report and move on.