220 Volt Metal Halide light circut

Thread Starter


Joined Nov 10, 2015
Hi, I have a shop with 5 parking lot lights and two of them have quit working. Today I disconnected the last light on the line by taking out the ballast and the ignitor for the metal halide bulb and directly connecting the socket to the line in preparation for a LED light to be installed. I do not have the LED bulbs yet just getting ready.

After bypassing the ballast and ignitor I turned the lights on and I could see via an amp meter that I was pulling about 3 amps less per 120 volt leg than before. The system was only running 3 amps per leg vs around 6 amps per leg before. That suggests to me that the old ballast or ingitor was using a lot of power trying to light that old or defective bulb or I have a component failure.

After 5 to 10 minutes all the lights went out and I had no amperage draw on either 120 volt leg. I noticed that this system had no neutral wire connected from the timer to the breaker box so I connected the neutral wire to the neutral bus bar and tried the system again. Now I have 11 amps on 1 leg and 11 amps on the neutral and zero on the 2nd 120 volt leg. I have the 3 original lights that worked before working again.

One of the 3 remaining lights that work must have a failing ignitor as it usually take about 5 to 10 minutes longer than the others for that bulb to light. I can't figure out why the system worked without a neutral for several minutes before quitting. Could the slow starting bulb/ignitor/ballast cause this? I am looking for advice on why the system is so different before with no power draw on one line and a high amperage reading on the other. I understand the load is imbalanced but my question is why did that happen after just hard wiring the last light on the line directly to the socket and bypassing the old stuff. The other question is it safe to run it until I figure out what happened?

Current system is using GE 400U multi vapor bulbs wired with 2 hots and a neutral coming into the building. I am looking to switch it all out for LED lights. Anyone have a recommendation on what and where to buy some LEDs replacements?

Thank you for any theories and help.