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Topic Title: New comer
Topic Summary: Some advice needed
Created On: 03 December 2017 01:58 PM
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 03 December 2017 01:58 PM
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JamesR32

Posts: 3
Joined: 03 December 2017

New to this site, looking for advice on a fault I found late Friday on an empty property.

Two boards, one split load. with an MCB off, i have 230v between and on 2/3 others with MCB off i have 109v and 112v and one has 188volts. Split load board does not trip.

House is empty, back next week to find. Wondered if anyone else has had this? May save me some time and frustration.

<any thanks guys

Edited: 04 December 2017 at 06:46 PM by JamesR32
 04 December 2017 06:47 PM
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JamesR32

Posts: 3
Joined: 03 December 2017

bump
 04 December 2017 10:38 PM
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AJJewsbury

Posts: 16095
Joined: 13 August 2003

Are you using a high impedance (i.e. electronic) voltmeter? If so it might just be capacitive coupling between circuits - quite common on a.c. systems, especially where everything is switched off. (Same underlying cause as low energy lamps flickering when switched off).

Or it might be cable damage or damp causing leakage between circuits, or even error in wiring (bridging two circuits that are meant to be separate.

If the voltage disappears when even a small load is connected between between the suspect L and N then it's probably just capacitive coupling and quite normal and harmless. Do be careful however - if it is one of the other causes, it could be quite dangerous. If the voltage (measured L-PE) disappears with the main switch open and insulation tests between circuits (L-L) show clear, it's again likely to be just capacitive coupling.

- Andy.
 05 December 2017 04:52 PM
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mapj1

Posts: 9689
Joined: 22 July 2004

Agree with the above. It may not be a real fault - you only need a few micro-amps to register a voltage on a modern DVM - in that sense the old test lamps may have been old hat, but had a lot going for them.
If nothing trips, why were you called in ? is there a real fault, or reports of tingles or anything ?
If it really makes no sense, it is also worth checking if the earthing arrangements are sound, if need be checking voltages between house CPC and a true ground from outside, such as a temporary earth electrode in the form of a garden fork or a long screwdriver in the lawn


M.

-------------------------
regards Mike
 06 December 2017 07:27 PM
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JamesR32

Posts: 3
Joined: 03 December 2017

Fluke T5-1000 tester being used.

We were called in as the customer has just purchased the property and upgrading lighting through out. We are back hopefully this week so will take all on board and see what I can find. Only reason I asked is the different voltage between mcbs as stated above.

Cheers guys, appreciate you taking the time to respond.

JR
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