[labnetwork] LED cleanroom lights

[Robert M. HAMILTON]

Norman Bergen,

I can share some information about LED lights with the same form-factor as
T-series fluorescent lamps. I think it's a great idea trying LED's in a
cleanroom. The interruption and act of re-lamping far outweighs the cost of
conversion. Beside lamp failures there are ballast failures which cause
odors and can smoke. The heat load for a cleanroom will also be reduced. I
note there are even yellow LED's in a T-series form-factor; however, I have
no experience with their light profile and its affect on photoresists,
Also, most fluorescent light troughs in buildings are powered 277 Volts so
one must select the appropriate LED replacement lamp - they do come in 277
V:  https://www.americool.com/277Volt.htm

My experience replacing older F15T lamps is via my hobby and not from our
cleanroom. I hybridize plants and have a growth room for vitro growth.
Nothing sordid; Andean orchids, note dope!. The heat load of my upstairs
room during the summer is sometimes excessive so I decided to re-lamp the
shelves with LED's which has proved effective.

The cost of LED's ended only slightly more than buying replacements T15's
at Home Depot because I ordered them as a case of ten. The wiring in the
existing fixtures needed slight modification. The existing "tombstone"
(bi-pin sockets) were of the shunted variety. Tombstones come both shunted
and un-shunted. A classical Hg-type lamp requires shunted bi-pins because
the lamp is powered from each end. The LED replacements requires power
across the bi-pins at either end. Replacing the tombstones was a piece of
cake. Out out laziness, the ballasts were left in the fixtures; however,
they were disconnected. Bypassing them was quite simple.

So far, so good. I am pleased with the light output and reduced heat load.
I've had no failures in a year. I run lamps rated at 5500K CRI given a
plants need for blue light. LED replacements are available at 4000K and
3000K, color temperatures that are less harsh. I have recently seen some
lamps advertised as direct replacements without the need of any re-wiring;
however, I have no experience with these.

Regards,
Bob Hamilton


[image: Inline image 1]


Robert Hamilton
University of CA, Berkeley
Marvell NanoLab Equipment Manager
Rm 520 Sutardja Dai Hall, MC 1754
Berkeley, CA 94720
Phone 510-809-8618 (desk - preferred)
Mobile 510-325-7557 (my personal mobile)
E-mail preferred: bob at eecs.berkeley.edu
http://nanolab.berkeley.edu/



On Tue, Jan 31, 2017 at 9:50 AM, Bergren, Norman F. (Fed) <
norman.bergren at nist.gov> wrote:

> Hi,
>
> We would like to change out our cleanroom lighting (T5) 277v to LEDs.  Any
> suggestions on what to use? Does anyone have experience with a change out?
> I saw
> Carnegie Mellon  and University of Chicago’s new installation and they
> seemed well done.
>
> Thanks
>
> Norm
>
>
>
>
> ************************************
> Norman F. Bergren
> Boulder Micro-fabrication Facility
> 325 Broadway Mail Stop 817.03
> Boulder, CO 80305
> 303-497-5344 <(303)%20497-5344>
> bergren at nist.gov
>
>
>
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