Low IR readings on EICR

[DimSpark]

Hi all,

First post so sorry if its not on the correct forum.

I have just had an EICR carried out on a property i am looking to purchase. It was built in the mid 70's and had an extension in the 90's, 3 bed-semi.

The C/U is outdated and some of the sockets are not fitted correctly - no issues getting these replaced.

The strange (and concerning) thing are the IR readings. All of the lighting circuits are fine (500M) but the sockets (up and down), cooker and immersion all have identical readings of 0.3M (L/N, L/E and N/E) which is obviously well below the minimum allowed. It seems rather coincidental that all of the them would have identical readings and i wonder if these are actually accurate? 

I don't really want to spend any more money having this investigated further in-case i do not end up completing on the property for whatever reason, but at the same time i don't want to complete and then find serious issues that require some or all of the wiring to be replaced. 

Any suggestions on the best way forward?

Thanks in advance for any replies. 

 

[Manator]

I would doubt that they are accurate. One thing in common with those circuits that are showing low readings are elements attached to them. To get proper readings they must be disconnected from the appliance, the heating element would reduce the reading as would any connected neon.

 

[Sidney]

0.3MΩ would have me looking for neons on the circuits. At a guess the cooker and imersion circuits would have a neon on the switch plate to indicate the power being on. I would bypass these and test again.

As the results are the same across L/N, L/E and N/E I would guess the inspector had just tested one of these combinations and put the result down in all the boxes.

 

[steptoe]

if its not been rewired since it was built in the '70s I'd be wanting to factor in a rewire anyway,

get it done before you move in and you know it will be good for another number of years with no disruption to your living

will also be much cheaper in a vacant property

 

[Murdoch]

I would get those circuits retested once you have possession .............................. I think that the loads were still connected.

 

[DimSpark]

Yeah it does sound like things were not properly isolated before the test was run. Frustrating as I paid good money for the report and the reason for the report in the first place was because of the age of the wiring, so the IR tests were the most pertinent part. 

 

[Murdoch]

How much did you pay for the report?

 

[DimSpark]

It was £160 

 

[Murdoch]

How many circuits?

 

[DimSpark]

8 circuits 

 

[binky]

Hmmm, cookers and immersions don't tend to give problem readings. Being single cable, single connection points they tend not to fail test. Get another sparky. I would also be interested in knowing how old the current board is, it is highly unlike;y not to have been changed at least once over that time scale.

 

[Ardet R]

Welcome.

I would suggest that perhaps this was a global test on all those circuits at once and the single item of failure therefore shows up on all circuits.

The result for LN cannot be correct if all items were not disconnected from the circuits and the ones to earth are very unlikely to be correct if everything was disconnected, so there is an anomaly here.

There are numerous items that can generate that level of reading, connected electronics is a good one.

Normally, but not exclusively, a low IR result at the 1 - 2 level and <0.1 may be a damaged cable but intermediate levels would have me thinking about connected loads.

 

[SirKit Breaker]

I would be interested to know which test method was used. Did he do conductor to conductor, in which case it will see the connected loads, or did he do Lives joined together to CPC, in which case it would eliminate the loads and give a more accurate reading. I would also be interested to know if the connected equipment survived the test voltage, or was it just a chancer who tested at 250 and hoped for the best because he couldn't be bothered to do it properly.

 

[DimSpark]

In case anyone wanted to know the outcome of this one - I had a sparky round to take a more thorough look at the insulation results (not the same one that carried out the tests). He re-ran the tests and confirmed that they had been carried out by connecting all of the circuits and testing in one go (and suggested here). He ran the tests on each circuit and traced it to some external wiring for floor lights and a socket outside the front of the property. The low reading was coming from the RCD located outside for this circuit. Changed it and all is now fine  

Thanks to everyone for the replies. 

 

[Murdoch]

In case anyone wanted to know the outcome of this one - I had a sparky round to take a more thorough look at the insulation results (not the same one that carried out the tests). He re-ran the tests and confirmed that they had been carried out by connecting all of the circuits and testing in one go (and suggested here). He ran the tests on each circuit and traced it to some external wiring for floor lights and a socket outside the front of the property. The low reading was coming from the RCD located outside for this circuit. Changed it and all is now fine  

Thanks to everyone for the replies. 

Good man - funnily enough I nearly asked about RCD's in my earlier response.

Low IR readings like that are often caused by RCD's

 

[Evans Electric]

Good man - funnily enough I nearly asked about RCD's in my earlier response.

Yeah  Yeah   we believe you Murdo  :innocent    Of course you did .   :redcard

 

[Murdoch]

Yeah  Yeah   we believe you Murdo  :innocent    Of course you did .   :redcard

Honestly gov

i have done so much fault finding over recent years you know the readings to look out for ......

 

[ProDave]

Good man - funnily enough I nearly asked about RCD's in my earlier response.

Low IR readings like that are often caused by RCD's

Remember to disconnect that pesky little thin white wire.  :Applaud