I've got a real head scratcher here. I work at a hospital that I can not name. My co-worker replaced a ballast with a new one and it was hissing at him. I brought another new ballast up and installed it. No hissing until I pushed all the wire back in. Grabbed the ballast by the wires and noticed the hissing was it arcing to the housing of the light. This is where my confusion starts. I check the voltage from hot to neutral; 277v. I check voltage from the neutral to the housing of the ballast; any where from OL to 0 to 800+volts. We had to change another one right across the hall and its doing the exact same thing. It was reading 700+ volts just having one lead on the housing and the other wasn't touching anything; thats where it went from confusion to a blown mind. The lights are hooked up in parallel with the old ones being t12 and the two new ones are going to be t8's; I wouldnt think this matters but trying to give enough info.
Again Im getting these high readings coming off the HOUSING of the ballast not the outputs.
How is this possible?
Now I am try to understand what you are try to do this .,,
if you are reading line to neutral connection that I do expect 277 which I know it is typical .,
But try to read the secondary ( lamp side ) connection the voltage will be much higher and the HZ will be way up the sky the conventail tester will not able read it very well which you should be aware with electronic ballast the old school mag ballast are easy to dealt with it.
What model the ballast that is installed in there? once we know which one it will be much easier to deal with it.
Ghost voltage is causing the readings since you say only one lead is connected.
As for the hissing some of the newer ballasts use push connections at the ballasts even for the factory wires and they are crap, causing what you said all fine till folding up wires.
Look and see if it has this type of connection at the base of the ballast.
Since it is not possible to have 700 real volts on a light fitting,
Then I would say your meter is picking up hash/radiation from the ballasts,
And if it's not perfectly symetrical than the meter will miss- interprate it
And give you some pretty wild results,
Just like a meter with a low battery can do !
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