insulation test on sensitive equiptment

[scottnomie]

just want someone to check me here

ive a lighting circuit with a 12v transfomer (fan), about 8 high..ish fluorescents and a bathroom with pir controlled ballast fluorescents approx 6 if i remember


now to insulation test, is it easy as joining the live and neutral together at the dist. box and test between them and earth, other than that its a heck of alot of disconnecting!!
would the pir handle it?

i've never needed to use this method, an i dont fully quite understand how it wont blow a ballast, or electronics?

thanks

 

[MarkieSparkie]

Yes, test IR with L-N joined, as the L-N are shorted the electronic circuitry will not see a potential difference, the only proviso is, if there any functional earths (e.g. RCBOs and telecoms equipment) these will need to be disconnected. Note on the paperwork that IR test carried out L-N joined.
You will only need to remove lamps, bypass PIR sensor and isolate the fan and it's transformer, if the previous test reveals low insulation <2M Ohms, when you will need to carry out a full IR test, between live conductors and between each live conductor and earth.

 

[Marvo]

If it's a standard ballast it should survive an IR test with the L+N connected together. If the ballasts are addressable with serial comms such as DALI then the comms system might use 0v earth referencing in which case any IR test even with the L+N connectec will cause damage. Same goes for some EPOS systems. I would refer to manufacturers data sheets for advice on insulation testing.

 

[scottnomie]

brilliant! see to that with a bit more confidence now!!

 

[Deleted member 9648]

Yes, test IR with L-N joined, as the L-N are shorted the electronic circuitry will not see a potential difference, the only proviso is, if there any functional earths (e.g. RCBOs and telecoms equipment) these will need to be disconnected. You will only need to remove lamps, bypass PIR sensor and isolate the fan and it's transformer, if the previous test reveals low insulation <2M Ohms. Note on the paperwork that IR test carried out L-N joined.

Why remove lamps?

 

[telectrix]

only if testing L-N would he remove any lamps.

 

[Guest112]

what if the boards a mess and the neutrals are all out of sequence

 

[SimpleSimon]

what if the boards a mess and the neutrals are all out of sequence

Then he's gona have alot of fun doing some finger tracing in the board to match up.

Sent from my GT-I9100 using Tapatalk