Well I have a box full of all kinds of muffin fans, some 120VAC and
others a mix of varous DC voltages, and installing a fan in a acrylic
enclosure would not incurr any additional $$, and can only be an
additional benefit since heat is a killer of electronics. I am just
thinking of how much space I need to allow around the enclosure I
make. I am sort of limited in space as to where it will be mounted,
and its certainly not the cleanest environment, so thats why I was
thinking adding a fan with filter for the internals in additon to
relying on the heatsink which will stick out the back of the
enclosure. I intend to make the lid sealed with a rubber gasket to
further keep chips etc out of it, so a typical electrical panel type
box would not be suitable. unless it wa a standard enclosure with no
knock outs etc that was designed to be totally water resistemnt.

My chassis is 2" high from the back plate, (not counting the heat sink
out the back as its not going to be included in the box) and measures
6.25" x 5.65" in size,. So do you think an enclosure with 1" space
all aroond the chassis itself would be ok? 8.25" x 7.65" x 3".

I am thinking of pulling air through the enclosures bottom through a
filter and directing the exhaust out and over the heat sink on the
back. Probably overkill but I want to ensure the controller has a
decent environement. Instalal insturctions are quite bland in mounting
it other than saying it needs to be in a place with no chance of dirt
and liquids getting on it........nothing in reagds to how much space
needs to be around it.


On Sat, 25 Feb 2006 10:10:40 -0700, "Al MacDonald"
wrote:
I bought a used DC controller off ebay for use with a 1.5hp 180v DC
permanent magnet Baldor, doing a retrofit on an old, cheap offshore BP
knockoff. The same controller could run a 90v DC motor and/or one with
field windings. Finally I can go slow enough! I was worried about metal
chips, etc. getting onto the controller but I was also worried about
cooling, as it didn't have an integral fan. I ended up mounting it in an
old steel electrical disconnect panel, which I put on the wall near the
input plug in.... well away from the mill and small chips (or dust in your
case).... and ran the motor power cable and low voltage control wires up to
the mill. I added an electronic tach also, so my control box on the mill
has start/stop, fwd/rev, variable speed pot, coolant switch and the tach
readout. The surface area of the metal box increases the heat sink
capability and I've had no problem with heat. I have a couple of VFDs good
up to 3hp that incorporate built-in fans already. The smaller hp models of
the same brand name don't have the fans.

al.

I recently bought a second new controller (off ebay) to run a duplicate
motor I have. It also has no cooling fan.
"~Roy~" wrote in message
. ..
I lucked up and found a source for KB Electronic DC controllers
locally that will sell to me wholesale. I had been going to buy one
controller in particular, that was already in an enclosure, but he
explained to me that I would be ahead in the long run buying another
model with the factory installed heatsink etc already on it, as it was
better than the ones yu could add a heat sink to as the components in
the chassis type had the items needing cooling already attached to the
heat sink, instead of just placing a heat sink against the enclosure
box itself.

So I bought the chassis type, but need to make a box for it. I plan on
making the box out of acrylic plastic, with the back of the box cutout
to allow heat sink to extend throuh outside of the box for cooling. Do
you think it would be a good idea to add perhaps a 1 1/2" muffin fan
or even a 3" muffin type fan to this acrylic box to pull air over the
internals that the box is now enclosing and duct it oput down and over
the heat sink? Or should I be able to just enclose the chassis and
have the heat sink exposed to ambient air for cooling? I do need to
enclose it as its going to be mounted in the lower section of my 20"
bandsaws base cabinet, which does get dust etc in it. I plan on
relocating the speed pot to the front of the saw for easy access just
like my old controller had..... HOw much space should I leave around
the chassis for air flow etc? I am driving a 1.5hp 107VAC 15 amp DC
motor.

Any suggestions appreciated.

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The original frugal ponder ! Koi-ahoi mates....


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( @ @ )
-----------oOOo(_)oOOo---------------


oooO
---------( )----Oooo----------------
\ ( ( )
\_) ) /
(_/
The original frugal ponder ! Koi-ahoi mates....