(Mike) wrote in
m:

Can anyone provide guidance on how large a timer I need for a 400W
metal halide grow lamp? The vendor suggested a 15 amp grounded
outlet, the stated he likes 20 amps ones. However, I recently ran
across some nice, grounded 10 amp, outdoor timers ( Intermatic . On
the side they list capcaity as 1200 amps R Resistive or 1200 amps
Tungsten. I know that Metal halides are different, but do I really
need a 15 amp timer or will these 10 amp ones work?

Thanks
Mike

A 10 amp timer will work for a while but it isn't designed for an
inductive load like a ballast which is basicly a transformer. Every time
the timer switches off the ballast acts something like the spark coil in
you car causing an arc across the contacts which eventually distroys them.
A 20 amp plug in timer will last longer but 95% of plug in timers aren't
designed for incuctive loads.
I couldn't find a web sight that had a good picture of what you shuld use
but I found one on ebay. note this is a dual voltage unit and you'll only
need a single 115/120 volt unit.

I've run my fluoresent lights (36-40 watt tubes or 1440 watts) for over ten
years with no problems.


http://cgi.ebay.com/ws/eBayISAPI.dll...ategory=42 89
7

Hope this helps
dusty