Metal Halide Starting Issues

[Variac200]

I have been at a lighting company not long and I have inherited a pending issue.
A 2000W metal halide fixture comes on when connected but when put off and even allowed to cool, it fails to come on.

My observations:
During initial start up, voltage across lamp sockets gradually builds from zero to 240v. But during times it fails to start, the voltage measured is about 400v.

Ballast specs: 2000w, 380v ( Lambada)
Capacitor: 50uF, 380v
Igniter: 2000W, 380v.

What could be possibly wrong?

 

[itsmoked]

Usually the bulb has failed. They only have about 15,000 hours in them. As they fail they need higher and higher voltages to produce less and less light. They cyclically extinguish when the voltage they need, rising with operation temperature, exceeds what the ballast can supply.

This can also overheat the ballast so it shuts off. The usual troubleshooting procedure is to replace the bulb. However you may want to consider replacing the head with LEDs.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Variac200]

Thanks for the response.
The fixture is fairly new. These problems happened just after installation.
What's the difference between a 2 terminal and 3 terminal igniter?