High Zs values

[Ajax123]

Just had a installation condition report done on my house in prep for selling it. It's an old installation, possibly thirty years plus with newer bits that I did in the late 90's. It showed up some high Zs results on the living room sockets which are on the same circuit that the dining room and hall ways are on yet they vwere fine. Is there a common fault that can cause this?? The results were higher than 1999. Can the Zs value be affected by stuff that is plugged in eg a phone charger that I now know has dodgy cable??

By the way I'm not an electrician so will be getting a man in to sort it out. Just curious to know what can cause problem on just a part of a curcuit

 

[Octopus]

Hum... was the circuit a ring circuit? was it tested end to end?

Not enough info except to suggest you get a spark to sort it......

 

[HandySparks]

If it's just some of the sockets affected, it might be just poor electrical contact between plug and socket due to tarnishing/corrosion or low contact pressure.

Or it might be a poor connection between wire and socket, depending on the circuit configuration.

Edit: see post No.5. A bit of tarnishing isn't going to increase the Zs to >1999 ohms.

 

[Richard Burns]

If your sockets are normally working OK from your point of view then a value of >1999Ω (the maximum range of the meter) for the Zs indicates that the sockets are not earthed.
This should not be possible if the end to end results of the ring were OK and other sockets on the ring had a good Zs.
This is possible if the earth for the ring is not continuous and it is also possible if the ring is interconnected so that there are two rings crossing each other.Θ

 

[HandySparks]

If your sockets are normally working OK from your point of view then a value of >1999Ω (the maximum range of the meter) for the Zs indicates that the sockets are not earthed.

Good point, I'd forgotten about the 1999 value when I replied.

 

[Octopus]

Back to the OP - what code did the inspector give this?

 

[Ajax123]

Hum... was the circuit a ring circuit? was it tested end to end?

Not enough info except to suggest you get a spark to sort it......

It's sort of pàrt of a ring main but one of the other problems they found was that the ring main is broken. No wasn't tted end to end. He just plugged in his gizmo box thing and it beeped and sàid 1999. He tried a second ocket in the living room and it did the same. When he tried one in the dinig room which is on the same these it as fine àt 0.6 I think.

 

[telectrix]

looks like you have a broken cpc. apart from the rfc not being intact. further investigation by a competent electrician is the next step.

 

[Ajax123]

Back to the OP - what code did the inspector give this?

When you say code are you talking about the c1 c2 c3 thing. It was a c2.

 

[Ajax123]

looks like you have a broken cpc. apart from the rfc not being intact. further investigation by a competent electrician is the next step.

Yes indeed. What's a CPC and a rfc.

 

[telectrix]

cpc is c ircuit protective conductor ( earth wire to the uninitiated) and rfc is ring final circuit.

 

[Octopus]

Could you scan and upload the cert? Obviously remove the testers details..... Could be interesting to read. How long was the tester in your house? And how much did you pay?

 

[Ajax123]

Could you scan and upload the cert? Obviously remove the testers details..... Could be interesting to read. How long was the tester in your house? And how much did you pay?

He was here most of the day. Not sure on price as my buyer paid but think it was £650. 33 notes including 5 knackered sockets, no earth on oil line, new RCD consumer unit needed, broken ring main and the high Zs values. Not sure how to scasn and post the cert as its 15 pages but will have a go. Some c3 Somme c2 and a couple of c1.

 

[Octopus]

He was here most of the day. Not sure on price as my buyer paid but think it was £650. 33 notes including 5 knackered sockets, no earth on oil line, new RCD consumer unit needed, broken ring main and the high Zs values. Not sure how to scasn and post the cert as its 15 pages but will have a go. Some c3 Somme c2 and a couple of c1.

£650 for an EICR, do you own a small castle?

15 pages, what were the C1's ?

 

[Ajax123]

£650 for an EICR, do you own a small castle?

15 pages, what were the C1's ?

Lol... It's a big old victoriàn villa. 5 beds. But typo £350 not £650.…... C1 s were a couple of dàmaged sockets and one is incorrectly wired according to his little test gismo.

 

[Octopus]

Lol... It's a big old victoriàn villa. 5 beds. But typo £350 not £650.…... C1 s were a couple of dàmaged sockets and one is incorrectly wired according to his little test gismo.

Damaged sockets are not C1 unless exposed live copper is present

 

[Ajax123]

Damaged sockets are not C1 unless exposed live copper is present

I thought it was hàrsh especially when the front on one of the consumer units is cràcked and this wàs a c2. Oh well.....