Insulation test between 2 different circuits

[Jimmyb]

Hi scratching my head alittle today as of why when I test between two different circuit I was getting 55 meg ohms on L and N and 1700ohm on E.

It is a horse stables and I can see one cable goto the the right hand side stables and the other stays in the left side stables, I thought it might of been a ring final as it was on 32amp MCB so tested it and found no continuity on L & N and 1700ohm on E hence the insulation test.

The owner says there is only wire going across to the other stables and its one I can see as he had to dig the trench to put it in for the last sparky, it was only a two way board before but he was told that when he upgraded the board he could split the circuit so to have left and right hand side stable sockets which is what I was going to do but found the above.

What im I missing here ?????

 

[Farmelectrics]

Further investigation is it two radials test point to point ie socket to socket you'll soon find problem are things still plugged in hence low reading

 

[PEG]

Is that between CPC's of both circuits? Are all or any items fed by these disconnected? Tin roofs,cladding,drinkers? As ever,the more information,the better mate. Have followed these round stables and found 3Kw IR heater panels or 7.5Kw showers glued to the ends...or even sneaky spurs with single sockets on the end,hidden in lockers so liveries can do a quick mane clip,stable owners non the wiser...

 

[R G]

Am I reading this right , there are 2 radial circuits and your getting an I/R reading between each circuit the lower reading on the earth between the 2 circuits ,
I can see why that may be happening , I think this is through the fabric off the building especially if its very damp , the higher reading between Lives and neutrals to earth is also associated with this , for Rcd protection I would use a single Rcd to cover both circuits in this case but on separate circuits as 2 radials , have you unplugged all equipment and is this still happening , it could also be leakage through an appliance...

I take it the continuity of the cps is the 1700 ohms , but you still have 55M ohms I/R between L&N to earth ,

 

[Farmelectrics]

First job I would do would be to identify each and every socket spur on each circuit

 

[Jimmyb]

I have made sure because there are only two sockets on the right hand side and have checked to see if any extra sockets have been taken.

PEG - Yes that's between the two circuits and yes all disconnected

RAY - Yes everything is unplugged, buildings are 5meters apart and yes there the readings.

FARMELECTRICS - That's the 1st thing I did

 

[R G]

Deleted

 

[MDJ]

Hi scratching my head alittle today as of why when I test between two different circuit I was getting 55 meg ohms on L and N and 1700ohm on E.

It is a horse stables and I can see one cable goto the the right hand side stables and the other stays in the left side stables, I thought it might of been a ring final as it was on 32amp MCB so tested it and found no continuity on L & N and 1700ohm on E hence the insulation test.

The owner says there is only wire going across to the other stables and its one I can see as he had to dig the trench to put it in for the last sparky, it was only a two way board before but he was told that when he upgraded the board he could split the circuit so to have left and right hand side stable sockets which is what I was going to do but found the above.

What im I missing here ?????

Something between your ears

 

[baldsparkies]

Earth = Ground, anything connected to ground ie building structure ect, how about socket types ie metalclad screwed to the biuldings frame or even to damp blockwork. ect ect ect.

Unless the cables cpc is completely isolated from every possible ground source your gonna pick something up.