IR Testing

[clematis432]

Hi,
When IR testing a circuit where voltage sensitive devices cannot be easily removed, and using test method 2 as per GN3, where they advise connecting line & neutral together and then testing to earth from this connection. Is there any reason not to just test between line & earth and then from neutral to earth ?
I,m probably missing something as usual but can,t see the reason for joining line & neutral together.
Thanks.

 

[telectrix]

you join L and E to avoid any possibility of applying the test voltage across a sensitive load. as they are shorted, they are at the same potential.

 

[IQ Electrical]

You can test at a reduced test voltage ie. 250V DC so as not to activate the voltage dependant resistor of the surge protection device. (1 MOhm still applies)

You join L+N together to prevent a potential difference across sensitive devices such as passive sensors and control gear etc.