Earth fault

luem · Apr 21, 2011

I have a house on an estate of 8 houses in Cyprus. The houses are modern and the electrics a good standard. The electricity to the houses is supplied alternately on 2 of the phases, the 3rd phase being reserved for street lighting. Each house has a box outside in which is the meter, 80amp fuse and a 63 amp DP isolator switch. Inside the house is a consumer unit housing the MCBs and a 63 amp RCCD (all Hager). My RCCD trips out for no apparent reason, at random times. The wiring from the CU onwards has been checked and there is no earth fault. I think the cause is an earth fault in one of the houses on the same phase. Could this be so? (I'm not an electrician!!) If it is, could I safely replace the RCCD with a 63 amp DP isolator switch? I have one outside socket and that is in an IP56 enclosure with an RCCD built in.

pushrod · Apr 21, 2011

luem said:
Thanks for that Pushrod. I had heard that the RCD can get flaky. How could I test it to find out.

You're right about Karsiyaka; we're on the seaside of the main road.

really need an rcd tester that is going to set you back a lot of cash - my multi tester cost me about £650 - they're not cheap! BTW should have said earlier if you do want to just try the swap a 30mA, 80A rcd will be more robust than the 63A version and will probs cost an extra £10.

luem · Apr 22, 2011

pushrod said:
really need an rcd tester that is going to set you back a lot of cash - my multi tester cost me about £650 - they're not cheap! BTW should have said earlier if you do want to just try the swap a 30mA, 80A rcd will be more robust than the 63A version and will probs cost an extra £10.

.

Thanks I'll try that. I am right aren't I - it should be 30mA and not 300 milliamps?

pushrod · Apr 22, 2011

luem said:
What's a front ender? and shouldn't they be 30mA? What do you mean by value of device? Remeber I'm not a spark, just a thick lawyer!!!
Just realized what you mean - yes I think the RCCD is rated at 300 milliamp, it's a Hager

The place we stay at is a new build (about 6 years old) and it has an ordinary 30mA Hager rcd in, with most of the mcbs protected by the single rcd - wouldn't be surprised if yours is the same, especially if it is under the same plastic cover as the mcbs . If you have anyone out there who can check for you it would certainly be useful.

Engineer54 · Apr 22, 2011

I hope your not so thick a lawyer, to have purchased a property on disputed land?? hahaha!!!

I would make the effort to employ a good electrician, to undertake any testing of your installation, and for him to convert your CU/DB. How long have you had your house?? Is it still under any form of warranty, ....or is that a rather silly question?? Get that electrician to give you a report on your properties electrical installation, if it's very bad, you maybe able to get the developer to pay for the RCBOs (he said ...tongue in cheek!!! lol!!) Also check if RCBOs are not as cheap in your neck of the woods as they are in mine, they may even be cheaper over there ....lol!!!

luem · Apr 22, 2011

pushrod said:
The place we stay at is a new build (about 6 years old) and it has an ordinary 30mA Hager rcd in, with most of the mcbs protected by the single rcd - wouldn't be surprised if yours is the same, especially if it is under the same plastic cover as the mcbs . If you have anyone out there who can check for you it would certainly be useful.

Sounds exactly the same! 6 years old 10 way non split Hager CU, hager MCBs and RCD

luem · Apr 22, 2011

Engineer54 said:
I hope your not so thick a lawyer, to have purchased a property on disputed land?? hahaha!!!

I would make the effort to employ a good electrician, to undertake any testing of your installation, and for him to convert your CU/DB. How long have you had your house?? Is it still under any form of warranty, ....or is that a rather silly question?? Get that electrician to give you a report on your properties electrical installation, if it's very bad, you maybe able to get the developer to pay for the RCBOs (he said ...tongue in cheek!!! lol!!) Also check if RCBOs are not as cheap in your neck of the woods as they are in mine, they may even be cheaper over there ....lol!!!

Disputed Land?! Round Larnaca and Limassol maybe, but not here!!! RCBOs in UK lot more expensive, and even more in TRNC

pushrod · Apr 22, 2011

Engineer54 said:
I hope your not so thick a lawyer, to have purchased a property on disputed land?? hahaha!!!

I would make the effort to employ a good electrician, to undertake any testing of your installation, and for him to convert your CU/DB. How long have you had your house?? Is it still under any form of warranty, ....or is that a rather silly question?? Get that electrician to give you a report on your properties electrical installation, if it's very bad, you maybe able to get the developer to pay for the RCBOs (he said ...tongue in cheek!!! lol!!) Also check if RCBOs are not as cheap in your neck of the woods as they are in mine, they may even be cheaper over there ....lol!!!

TBH engineer i've seen quite a few new builds on the turkish side and the standards are fine - most with 16th rather than 17th edition boards, mind that is hardly surprising - it is the old property that is scary.

Engineer54 · Apr 22, 2011

pushrod said:
TBH engineer i've seen quite a few new builds on the turkish side and the standards are fine - most with 16th rather than 17th edition boards, mind that is hardly surprising - it is the old property that is scary.

I know what you mean, but the Cyp's will always make things look nice on the surface, it's only when you start digging around deeper, that the anomalies start appearing!!!....lol!!!

The old properties are much easier to see what's lurking, ....electrically speaking, nowhere to hide the cock-ups!!! I'd be more worried about the place falling down on my head ...lol!!!

MarkieSparkie · Apr 22, 2011

i=p/u said:
testing the leakage on your earth system, what instrument would you use again as i forget, im thinking clampmeter but i reckon the range on this isnt low enough??? just a quickie

A special type of clamp meter i=p/u, it has very sensitive mA current ranges, typically at 0.01mA resolution and usually has additional filtering to reduce the effect of harmonics/noise from the measured value, as well as a maximum value hold switch.