Insulation resistance testing on 230v equipment

[lyledunn]

Just as a matter of interest, when testing equipment with smpsu and filtering equipment, can an insulation resistance test at 500v from a PAT tester cause damage? PAT tester links phase and neutral and tests between these 2 conductors and earth.

 

[gjones33]

Yes

Regards,
G

 

[kvkev]

It is ususally not appropriate to test smpsu and filters at 500 v, because as already advised it can cause damage, and would also fail the test. Other circuits such as the power save mode on some computer monitors use a bridge of 4 x 330 ohm resistors which will return a value of 0.3 to 0.4 Mohm form a tied line neutral to earth test.
It is more reasonable to skip the insulation resistance test and perform a functional earth leakage measurement. This value (U.K) should be less than 3.5 miliamps.

Regards,

KVKEV

 

[electricpete]

what's smpsu? what's pat?

 

[kvkev]

smpsu- switched mode power supply unit.
PAT - Portable Appliance Test

Regards,

kvkev