continuity

[scott 123]

Cables in con unit suggest bonding to gas and water.but I can't find connection..is there a way i can I test for it

 

[Richard Burns]

Not with surety.
All you can say is that the connections are not available for testing (however they should be available for testing, but are often boxed in)
Even if you test continuity from the MET to the nearest point of entry of the metallic service you will very likely get a low reading as there will be interconnections from boilers, etc that will give a low reading so it cannot be proved there is bonding present without being able to test the end to end continuity of the bonding cable.
However if you test continuity and you get a high reading then you can almost certainly say there is no bonding or it not connected.

 

[Andy78]

EDIT: beaten to it

 

[overskilled]

Check between met and gas /water pipe itself?

 

[Pete999]

Cables in con unit suggest bonding to gas and water.but I can't find connection..is there a way i can I test for it

https://www.youtube.com/watch?v=rnvNfI__kYU

 

[malcolmsanford]

Overskilled that is what Richard pointed out even doing a R2 test there is a good chance that you will get some sort of reading if there is metal work throughout the installation, by picking up parallel paths.

If you don't get a reading of any kind then I would do an IR test with the MET to confirm that there is no potential

 

[scott 123]

What reading would I be looking for on an IR test

 

[malcolmsanford]

greater than 23Kohm result and the metal work is not classed as an Extraneous conductive part

I think it is still in GN 8 it certainly was in the green one

 

[overskilled]

Overskilled that is what Richard pointed out even doing a R2 test there is a good chance that you will get some sort of reading if there is metal work throughout the installation, by picking up parallel paths.

If you don't get a reading of any kind then I would do an IR test with the MET to confirm that there is no potential

Wasn't a reply when I hit post. Consider entry retracted

 

[Guest77]

Not with surety.
All you can say is that the connections are not available for testing (however they should be available for testing, but are often boxed in)
Even if you test continuity from the MET to the nearest point of entry of the metallic service you will very likely get a low reading as there will be interconnections from boilers, etc that will give a low reading so it cannot be proved there is bonding present without being able to test the end to end continuity of the bonding cable.
However if you test continuity and you get a high reading then you can almost certainly say there is no bonding or it not connected.

Agree with this 100%

 

[HappyHippyDad]

Not with surety.
All you can say is that the connections are not available for testing (however they should be available for testing, but are often boxed in)
Even if you test continuity from the MET to the nearest point of entry of the metallic service you will very likely get a low reading as there will be interconnections from boilers, etc that will give a low reading so it cannot be proved there is bonding present without being able to test the end to end continuity of the bonding cable.
However if you test continuity and you get a high reading then you can almost certainly say there is no bonding or it not connected.

Would you ever use the 0.05Ω suggestion Richard in GN3 to confirm a bonding connection if the bonding clamps are unable to be found?

 

[davesparks]

Would you ever use the 0.05Ω suggestion Richard in GN3 to confirm a bonding connection if the bonding clamps are unable to be found?

That figure is suggested for the resistance of the connection to the part being bonded only, not the bonding cable. Ie you test between the cable terminal of the earthing clamp and the pipe it is attached to and this should have minimal resistance with 0.05 being the suggested guideline maximum

 

[Pete999]

That figure is suggested for the resistance of the connection to the part being bonded only, not the bonding cable. Ie you test between the cable terminal of the earthing clamp and the pipe it is attached to and this should have minimal resistance with 0.05 being the suggested guideline maximum

Are you sure about that? I think the ruling is that the recommendation is that the main bonding' resistance should be 0.05 Ohms, anything greater then you should look into increasing the CSA of your main bonding conductor. The figure of 23Mohm relates to the resistance of any extraneous metal work measured from a known earth, anything less then that makes it an extraneous part and thus should be bonded.

 

[telectrix]

sorry pete, dave is correct.

 

[Pete999]

sorry pete, dave is correct.

https://www.youtube.com/watch?v=rnvNfI Check this vid out or am I miss understanding it seems quite clear to me