I'm wondering if metal halide fixtures with pulse start lamps are nonlinear loads. This will determine if I need to derate the service conductors and panel feeders to 80 percent due to 4 wires in a conduit (NEC 310.15 B2 and B4).

Steve

Yes it is, as is discharge lighting in general.

Yes

thanks.

Dare I say No?

Are these electronic ballasts?

The cuts I just checked were magnetic.

hey engy all magataic and electronic ballast do make non liner load so no matter what type the ballast it will make that effect and cant expect to be better than magatic ballast if you read the volts and current ratio it is not the same as indscent or liner loads are and some ballast manufacter will put it in called ballast factor it is hard for me to explain that meaning but scott35 or other members can make a chart to show how it can affect it

merci marc