resistance reading between neutral and earth

[Dan oh!]

I have a reading of 5ohms when checking resistance between neutral and earth, it's a TNCS installation. Is this a little low? I checked this after finding spurious readings on a central heating boiler, whilst doing preliminary electrical checks. Any help, anyone

 

[telectrix]

i'd say it was high. poor connections somewhere.

 

[Dan oh!]

What resistance would be expected? I know the neutral and earth join after the circuit board, back to the sub station, so resistance would be reasonably low, but this is quite a large industrial premises

 

[telectrix]

thought you were measuring at DB. if you're measuring a a point on a circuit, the reading will depend on the cable from the DB. even so you should find that Rn+R2 is equal to R1+R2.

 

[Guest123]

Are you talking insulation resistance or continuity??

 

[Deleted member 9648]

Dont get what you are trying to achieve....It's a TNCS so you would expect a low resistance between N-E anywhere on the system with N and E still connected...and if you are IR testing it would not be possible to register a reading of 5 ohms.

 

[Dan oh!]

Thx for yer help, I was being a nugget!