New house, no main water bonding

[ash_s3]

Just been to a new house (5 years old) which had no main equipotential bonding to the incoming water. Gas was bonded with 10.0mm
Checked on original EIC and water service box was marked N/A
All pipe work inside the house is copper but the supply pipe is plastic up to main stop tap

Surely this isn't right?

 

[trev]

Correct, it is not right, the internal metal pipework should be bonded.
There's an unless figure but I can't remember what it is

 

[rich.250]

23000 ohms.

 

[trev]

I thought 22k but wasn't sure cheers Rich

 

[ash_s3]

I though it needs bonding unless ALL internal pipe work is plastic.
Might see if neighbors houses are the same.
I assumed there would be no issues with this property with it being so new.
Dual rcd board - check
gas bond - check
water bond - err... It must be here somewhere!

 

[rich.250]

Only need to bond a parallel path. Could be a section in plastic, best bet is to test it. If its over 23 000 doesn't require bonding.

 

[Richard Burns]

From OSG "There is no requirement to main bond and incoming service where the incoming service pipe and the pipework in the installation are both of plastic. where there is a plastic incoming service and a metal installation within a premises main bonding is recommended unless it is confirmed that any metal pipework within the building is not introducing an earth potential."

IF an IR test between MEt and the metal pipework give a value <22Kohm then the metal internal pipework should be bonded, if it is greater than that then there is no need to bond as it is not introducing an earth potential.

There is some variation in the IR figure depending on who you listen to but generally if it is not connected to earth then there is not need to bond plastic incomers.

 

[J&M Electrical]

So am i right in thinking that if the main feed, stop tap and (for arguments sake) 1st 6m of consumers pipe is plastic, but the rest is copper you bond your main bonding as soon as it changes to copper?

I have never actually worked on a property like that before so its new to me.

 

[trev]

Unless there's more than 22k ohms IR that's about the size of it

 

[ash_s3]

Right, so pipe work needs to be >22,000 ohms. Is this IR test carried out at 500v?

 

[rich.250]

I would carry out a continuity test. And if over 23k ohms then it does not need bonding. Taking this from a 'safe' touch current of 10mA.
230\0.01= 23,000 ohms

My opinion of the OSG is proving to be more true each time I hear stuff from it. I don't like it to say the least.

Yes if it's all plastic and you can see it is. Then it's pointless testing.
But if there's any copper id check as its your --- on the line if it ain't right.

 

[rich.250]

Continuity test.

 

[ash_s3]

Well it's all copper so needs testing.
Entire plumbing install is copper right up to the supply pipe.

 

[rich.250]

Yeh best get the tester out.

 

[ash_s3]

Will my tester test up to that value? Megger 1553