Testing a Conduit Earting System

[chloebear]

Hi All,
I have to carry out some work on an installation that has its earthing run as part of the metal conduit system. This raises a few questions apart from checking to ensure that the conduit, and therefore, the earthing is intact.
(1) using NICEIC paperwork, what do I record for the CPC size?
(2) Checking R1+R2 - what would be the best way to do this? as basically I have no R2 apart from the earthed conduit.
(3) whats the best way of carrying out Insulation Resistance Tests
(4) are there any further recomended tests to carry out for this type of installation

 

[andyb]

(1) Just write conduit or con
(2) Record R2, use a long lead for this
(3) Carry out insulation resistance as normal, just put your croc clip onto the conduit
(4) None really, just make sure all visible joints and connections are good.

 

[IQ Electrical]

Hi All,
I have to carry out some work on an installation that has its earthing run as part of the metal conduit system. This raises a few questions apart from checking to ensure that the conduit, and therefore, the earthing is intact.
(1) using NICEIC paperwork, what do I record for the CPC size?
(2) Checking R1+R2 - what would be the best way to do this? as basically I have no R2 apart from the earthed conduit.
(3) whats the best way of carrying out Insulation Resistance Tests
(4) are there any further recomended tests to carry out for this type of installation

Make sure that each accessory has a green/yellow fly lead linking it to the back box, this is a requirement where the containment system is the cpc.

 

[Deleted member 9648]

You can measure R1R2 in the normal way.....the R2 is the conduit instead of a copper wire,but the principal is the same.

 

[Kamikaze]

As all the others have said but if you want to be a NICEIC blue eyed boy use these figures for your cpc sizes.
Heavy gauge steel conduit to BS 4568 Part 1
16mm diameter= 64.4mm csa
20mm diameter= 82.6mm csa
25mm diameter= 105.4mm csa
32mm diameter= 137.3mm csa

Steel surface trunking to BS 4678 Part 1
50x50mm = 135mm csa
75x75mm = 243mm csa
100x20mm = 216mm csa
100x100mm = 324mm csa
150x100mm = 378mm csa

Pyro 500V light duty
2L1 = 5.4mm csa
2L1.5 = 6.3mm csa
2L2.5 = 8.2mm csa
2L4 = 10.7mm csa
3L1 = 6.7mm csa
3L1.5 = 7.8mm csa
3L2.5 = 9.5mm csa
4L1 = 7.7mm csa
4L1.5 = 9.1mm csa
4L2.5 = 11.3mm csa
7L1 = 10.2mm csa
7L1.5 = 11.8mm csa
7L2.5 = 15.4mm csa

 

[IQ Electrical]

They are figures that I'd use for design parameters but I wouldn't expect to see them entered on a test sheet, the NICEIC testing manual records the use of conduit as a cpc as 'con' on the cpc section of circuit details.

 

[Kamikaze]

They are figures that I'd use for design parameters but I wouldn't expect to see them entered on a test sheet, the NICEIC testing manual records the use of conduit as a cpc as 'con' on the cpc section of circuit details.

Very true and I agree. If you are using software such as Amtech then you would not be able to enter con, sheath, swa or such like. However, it is possible to use the drop down list and choose the equivalent size. The NICEIC prefer the use of software for validation purposes. It takes the human mistake element out of certification. We have given up using it because it is pants. You can’t beat using your own judgment.

 

[IQ Electrical]

Very true and I agree. If you are using software such as Amtech then you would not be able to enter con, sheath, swa or such like. However, it is possible to use the drop down list and choose the equivalent size. The NICEIC prefer the use of software for validation purposes. It takes the human mistake element out of certification. We have given up using it because it is pants. You can’t beat using your own judgment.

Every report/certificate that we complete is computer generated but purely because it looks so good next to some hand scrawled competitor's report!

Also, it allows us to send reports/certificates as .pdf files.

We never use the validation part of the software, I cast my beady eye over every result!

 

[Kamikaze]

What software do you use or do you have your own spread sheets?

 

[IQ Electrical]

We use formfill 9 by Castline