[Truelivewire]

We have wired up 30 lights on 3 different circuits and before we powered them up the client asked us to megger the lighting circuits. To my understanding you are not able to megger from line to neutral through the fixture as you will damage the ballast. One of the journeyman on the crew pointed out that if you megger with the line and neutral together and to ground that you will not damage the ballast be because there is no potential between ballast leads. Does anyone out there have experience with this?

 

[backstay]

We have wired up 30 lights on 3 different circuits and before we powered them up the client asked us to megger the lighting circuits. To my understanding you are not able to megger from line to neutral through the fixture as you will damage the ballast. One of the journeyman on the crew pointed out that if you megger with the line and neutral together and to ground that you will not damage the ballast be because there is no potential between ballast leads. Does anyone out there have experience with this?

I would do as the client wishes after he signs off on the damage waiver to the ballasts. Think how much you will make replacing them. Or you could pull the disco to the ballasts and meg away. I would charge for this if it wasn't in the original scope of work.

 

[EcHoMaN]

 

[EcHoMaN]

 

[macmikeman]

Echoman has it right. You are counting on the ballast to be perfectly insulating if you try the method you described to meg the circuit conductors. The ballast components are not well enough insulated from the ballast casing or grounding method on the circuit board to withstand high voltage impress. Even with a plastic case ballast.

 

[Marcus]

We have wired up 30 lights on 3 different circuits and before we powered them up the client asked us to megger the lighting circuits. To my understanding you are not able to megger from line to neutral through the fixture as you will damage the ballast. One of the journeyman on the crew pointed out that if you megger with the line and neutral together and to ground that you will not damage the ballast be because there is no potential between ballast leads. Does anyone out there have experience with this?

This is how I have always done it, or just megger line - earth. Problem with meggering L-N, even at rated voltage, is you'll probably end up with a dead short from the circuit load or electronics in the circuit.