Insulation resistance for periodics

[mst]

Hi,

Ive heard you can do a insulation resistance test by short the live and neutral together at the board, then tests to earth can be written as limited.

Sound right to you.? also how would you go about this?





EDIT Any views would be welcome

 

[Dippy]

Yes. When the circuit contains electronic devices which cannot be isolated, you have no other choice since the higher voltage applied during the test might cause damage.

As to how you go about it - it appears that you already answered your own question!

 

[Spark123]

Almost, the L-N (Live-Live) test will be limited. Needs to be recorded in the extent an limitations.

 

[mst]

Great thanks for the reply,

but... where do you short the live and neutral too.

Sounds silly but im on a mental block this week

Ive always done it the long way around which in fairness might be the best way!

 

[Spark123]

You need to disconnect phase conductor from the MCB etc, neutral from the neutral rail, connect the phase and neutral conductors together. IR test between the two conductors and earth.

 

[RF Lighting]

You connect the live and neutral together, and then test between L&N and EARTH.

This should only be done if it really is not possible to test L>E, L>N, and N>E

<edit> Pah!

 

[Taylortwocities]

Yes, you must disconnect neutral from earth to do this correctly on all circuits otherwise your neutral&live to earth reading will show as short circuit.

eg in TNC-S neutral=earth!