Subject: Dimming HID Lamps ?

From: [email-masked] (Chris Young)
Date: Wed, 6 Sep 1995 14:13:45 GMT

I am wondering if anyone has experience dimming metal halide lamps.
The application would ideally vary the light output with the occupancy of
the area. It is my understanding that there is a product by Wild/Keene (sp?)
that provides various programmable light levels. Any contacts with this
company or experience with similar applications would be appreciated.
Thanks,
Chris

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From: [email-masked] (ZARNOTT)
Date: 7 Sep 1995 20:02:56 -0400

I would contact some of the people at Lithonia Lighting about dimming HID
lamps.  

Your application sounds reasonable.  Expect to dim the lights only 30% to
50% with the occupany sensor and expect a noticable color shift.  For
non-clerical areas like warehouses...this is a good use of the current
technology.  You must weigh the costs and benefits.

Mike Zarnott
Business Development Resource
(800) 842-7608

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From: [email-masked] (Ilumenator)
Date: 7 Sep 1995 21:09:06 -0400

In response to Chris Young's inquiry about dimming metal halide lamps,
several manufacturers offer this capability. I personally have had
experience with both WideLite and Cooper.  The technology is limited at
best, but is useful in warehouses and other areas where the color shift
won't be objectionable.  You may find the cost to be rather prohibitive,
though.

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From: [email-masked] (John Fulton)
Date: Sat, 9 Sep 1995 03:18:17 GMT

In message <[email-masked]> - [email-masked] (Ilumenator)
 writes:
:>
:>In response to Chris Young's inquiry about dimming metal halide lamps,
:>several manufacturers offer this capability. I personally have had
:>experience with both WideLite and Cooper.  The technology is limited at
:>best, but is useful in warehouses and other areas where the color shift
:>won't be objectionable.  You may find the cost to be rather prohibitive,
:>though.

My best advice is don't!!

But if you must one of the two level switching systems
is by far the bect to use.

The lamp operating poins (Voltage and current) are quite
critical for proper colour, and lamp life.  A variable
dimming system is unlikely to be satisfactory in most
applications where dimming is required.

I have recently deleted dimming from a large contract
that had specified dimming for Metal Halide lamps.

/*  John ER Fulton - Ngaio - Wellington - NEW ZEALAND
/*  Phone / FAX +64 4 479 2043