Failed resistance test

[woodbutcher32]

Evening all, during a recent electrical survey my
small terraced house failed on a lighting resistance test
(came up 0.6 when im told it should be at least 2)
can somebody please give me some pointers on how i can test this and possible causes?
Cheers in advance.

 

[GLENNSPARK]

I take it all loads on this circuit were removed prior to the test...including any smokes/heats etc?.........

 

[woodbutcher32]

Cheers for the reply Glenn, Im a joiner by trade
so you'll have to bare with me, there are no smoke
detectors or heaters on the system, the system isn't
looped either if that helps!?

 

[Octopus]

Cheers for the reply Glenn, Im a joiner by trade
so you'll have to bare with me, there are no smoke
detectors or heaters on the system, the system isn't
looped either if that helps!?

Forgive me for asking this but do you think you have sufficient experience and knowledge to do testing, if you're looking for pointers for what may cause a low IR?

 

[GLENNSPARK]

its a minimum of 1 meg n all. Unles that is your testing the lot at once (at the tails) in which case its 2 meg. Any less than that you test each circuit seperately to avoid parrallel resistances. If though it still comes in at between 2 meg and 1 meg....i woulod recommend to the client that the cable insulation is on its way out and the install (or parts of it) are due for replacement..........

 

[GLENNSPARK]

Table 2.2 p(38) guidance note three...........

 

[GLENNSPARK]

you test at the board between all conductors on that circuit remembering to test strappers in both directions..........

 

[Des 56]

What came up as 0.6 ?

There are three readings live-neutral, live-earth and neutral earth
The test may even have been done with the live and neutral connected together, because lamps/transformers /dimmers etc couldn't be removed or someone couldn't be arsed to do so

Do you have external lights ?
Were electronic devices dis connected before the testing took place ?
Was the lighting test done as an independant test seperated from other circuits ?


The single only figure that you gave seems to indicate a jointed live and neutral which was tested to earth

If so it should state that it was done with this method on the certificate
If this 0.6 was for the three columns of results,it may be unreliable being so exact

 

[telectrix]

it could even be due to a bit of damp. does need further investigation though, as it could be a potential breakdown of insulation.

 

[woodbutcher32]

The test result was (ne) the spark said he will start to investigate at £50
An hour, naturally im a little worried at what the total cost could eventually
be!
I realise its very hard to put a time scale on it but can anybody have a stab at
a ballpark figure!?

 

[netblindpaul]

woodbutcher,
Where are you located?
It is impossible to put a ball park figure on things, without knowing more about the install & circuit.

 

[Paul.M]

How old is the install? Was all the loads (bulbs) taken out if not did they do the correct L+N to earth? Who is going to test this for you again?

 

[Paul.M]

The test result was (ne) the spark said he will start to investigate at £50
An hour, naturally im a little worried at what the total cost could eventually
be!
I realise its very hard to put a time scale on it but can anybody have a stab at
a ballpark figure!?

£50 p/h to fault find in a house is steep for a house, maybe the first hour then a reduced rate. Post up your area and let the real sparks on here sort it out for you without being done over.

 

[netblindpaul]

paul.m
The rate depends mate, what if the OP is in the middle of Central London with the congestion charge and other increased overheads to consider?

 

[telectrix]

without london overheads, £50 an hour is a bit steep. nay, a lot steep. £20-£30 is more like .