Help Please Low Insulation Resistance

[gregi]

Hi all, new to the forum, so please be kind. I have just had an electrician in to add 2 sockets. before he started work he carried out an insulation test on the socket ring, and informed me that the readings were too low. less than 0.2 on phase/neutral, phase/earth and neutral / earth.? He told me that this was too low, and advised me to get the system tested. He didn't charge for his time so i tend to believe him, Can anybody advise what need to happen, and if there is anything I can check out as money is tight??

thanks in advance

 

[andy]

less than 0.2.... shud go band when connected to mains?

 

[plugwash]

he didn't give units

0.2 megohms was perhaps what was meant?

 

[Lectrician]

He may have seen your install visually and felt a quick check was needed first to ensure all was ok......which it looks like it isnt.

Do you live in a cottage?? Any damp anywhere??

0.5Mohm is the passable limit, but this must still be looked at as suspect.

 

[Lectrician]

He may, of course, have a new meter, and new testing 'skills', but forgot to unplug everything, isolate all 'fixed' equipment on the ring (or missed one), and may of even forgot to seperate N, E and L at the fuseboard from all other circuits.

 

[gregi]

lectrician -He may, of course, have a new meter, and new testing 'skills', but forgot to unplug everything, isolate all 'fixed' equipment on the ring (or missed one), and may of even forgot to seperate N, E and L at the fuseboard from all other circuits.

Hi thanks for your responses - firstly sorry - he wrote down the results - it was .2 mohms. He showed me the test , the guy took out the neutrals and earth and put them in connectors - the reds he left connected. I have an old re-wirable fuse type fuse box. He then tested each bit and showed the results. What do you mean by fixed equipment? he did go round and un plug everything, even disconnected the security light. what might he have missed?

The house ring is one fuse for both floors if this helps?

 

[Damocles]

Did he test the other circuits, and if so were they ok or also showing the same problem?

Fixed equipment means anything which is wired directly into the power and so does not have a plug. Might mean cookers, water heaters, fans. Possibly washing machines or suchlike under the worktop in the kitchen. Garbage crucncher under the sink? Outside lamp running from a spur switch connected to the ring? power to the shed? bathroom heater? shouldn't be, but shower; or power shower?

If you switch off just the ring (switch off box, remove fuse, turn back on) then see if there is anything now not working which you did not realise before was connected to it.

It can be quite hard to remember everything you have got connected. Maybe even forgot a socket somewhere. Many electrical devices might cause this result if they were connected.

 

[gregi]

Thanks all for your responses, I have looked around and think that I may have missed a few things that were still connected. However these are the Boiler (FCU) and alarm (FCU).
Just for my interest whats the best way of dissconnecting them so the test can be carried out

 

[supersparks]

Thanks all for your responses, I have looked around and think that I may have missed a few things that were still connected. However these are the Boiler (FCU) and alarm (FCU).
Just for my interest whats the best way of dissconnecting them so the test can be carried out

the best test to do would be phase(live)+neutral - cpc(earth) this way you wont need to disconnect anything if its wired properly