Re: Electronic Ballasts from Grainger

>I know that I want a 4 tube ballast that will work with T8 tubes, but I also
>want it to work for my current T12 tubes.  The prices are really nice, with
>none of the 4 tube ballasts over $60, and most of them not over $45.  I'm
>looking at the following parts:

An electronic ballast won't work with both T8 and T12 lamps. You have to
get a T8 ballast for T8 lamps and a T12 ballast for T12 lamps. It's
important to match the ballast correctly to the lamp or you get less light,
shorter lamp life, and higher energy consumption.

>BLST-(4)FO32T8, 120V     75% LIGHT OUTPUT
>4/17-40W RH BLST 120V    I assume this is a reduced harmonic ballast too.
>4/34-40W R/S BLST 120V   4 LAMP 34-40W 120V T-12 RAPID START BALLAST

I have a Grainger catalog--paper version. In the chapter on fluorescent
ballasts are Advance and Magnetek rapid start, parallel electronic
ballasts. Look for four lamps with high power factor. Unfortunately, I
can't find numbers that match those you got from the online catalog. The
Magnetek four-lamp I use for T8s is Grainger Stock No. 3V957.

>What I'm not certain of is that any or all of these are electronic ballasts,
>and what the reduced harmonic means or the 75% light output means.

Don't see the 75% info in my catalog so can't comment. Don't worry about
harmonic distortion. Unless you're running an office building with hundreds
of ballasts, it's not going to matter.

>Some of the ballasts were marked as dimming
>ballasts.  Do they just kill one light at a time or do they actually dim a fl

They actually dim all the lamps hooked up to it, and are more expensive as
a result. You can probably find a timer and photo sensor (for even more
money) and set up your dimming ballast so it delivers gradually more light
in the morning and gradually less light in the evening. That's what the
more advanced office lighting design does, especially for fluorescent
lights near windows.

Greg. Tong
San Francisco, CA, USA
gtong at sirius_com

"Every infinity is composed of only two halves."