Main bonding value

[Mr.Black]

Hi all,

just took main protective bond (10 mm) to water pipe which is of the old lead type.

Main bond length is about 4 meters.

Cross bonded to rads and sink(utility sink)

Then did R2(using 2.5mm) to pipes under the kitch sink.

Reading was 0.10 ohms.

regs say max allowed value is 0.05.

This reading seems a bit high.Anyone got any reasons for this(plumbers joints,lead pipe,or 2.5 R2 lead) and would it be acceptable.

Need to know as Napit assessment is due on the start of June...............

 

[ezzzekiel]

possibly resis of test leads or poor connection,can you see the run throuhout its length? theres no value to mark up, just prove continuity exists

 

[m4tty]

possibly resis of test leads or poor connection,can you see the run throuhout its length? theres no value to mark up, just prove continuity exists

tbh I thought 0.05 was the limit too? Cheers

 

[chris gray]

0.05 is the limit, but you dont have to give a value.
when you did your continuity reading did you deduct the resistance of your 2.5 test lead?
also you shouldnt be teminating onto lead piping mate

 

[Deleted member 9648]

There is no requirement for contnuity between the main bond at the stop**** and pipework/sink in a kitchen ,so it can be open circuit and still comply with the regs......cant see why you are testing it.As long as your main bond is on the consumers side of the stop**** and before any branch pipework,thats all that matters.
The 0.05 ohms is continuity between the MET and main bond position.

 

[Guest123]

Agree with wirepuller....the 0.05 value is for the resistance of the actual bonding conductor from the MET to the earth clamp.

 

[Mr.Black]

Cheers fellas, i know what i've done......school boy error.....Didn't subtract the resistance of the R2 lead..

With the assasisnation sorry i mean assessment coming up i'm thinking way to much into things.

 

[ezzzekiel]

possibly resis of test leads

damn im good - lol