low M-ohm

[jonthesparks]

doing an Ins resistance test across all circuits at the CU with load bridged out( L-N shorted ) I have a low reading - 1.03M ohm . after investigation found this low reading goes once the boiler spur is isolated .
any one had similar results ?
this is not the first time ive had appliances give low readings , fridge and extract fan also gave low readings on different properties
any idea why ?

 

[telectrix]

any appliance with an electronic pcb is liable to give low IR readings. unless you have too many on an RCD< it's not likely to cause tripping problems.

 

[AndyL]

doing an Ins resistance test across all circuits at the CU with load bridged out( L-N shorted ) I have a low reading - 1.03M ohm . after investigation found this low reading goes once the boiler spur is isolated .
any one had similar results ?
this is not the first time ive had appliances give low readings , fridge and extract fan also gave low readings on different properties
any idea why ?

Is this for an EICR or fault finding?

 

[Deleted member 72666]

Why not disconnect all loads and test properly?

 

[Octopus]

I do hope he's not doing a CU change!

L&N to earth tests seem to be the norm now but don't really give a realistic picture!

 

[Edd]

doing an Ins resistance test across all circuits at the CU with load bridged out( L-N shorted ) I have a low reading - 1.03M ohm . after investigation found this low reading goes once the boiler spur is isolated .
any one had similar results ?
this is not the first time ive had appliances give low readings , fridge and extract fan also gave low readings on different properties
any idea why ?

remember your only testing the installation up to the fused spurs, this is something that should be mentioned on the test cert. all items after that should be disconnected.. Nothing like sending 500v into a boiler PCB...