Not long ago, I made a shop fan from squirrel cage fan out of a
residential air handler. Last weekend was particularly hot, and I had
the fan running most of the day. When I went out to turn it off, the
fan was running but there was a puddle of oil underneath it. Now, or
course, it won't start. I assume the capacitor blew up or leaked.

Can a fan such as this be used for continuous use, or is it only suited
for on and off operation, as occurs in the normal cycling of an air
conditioning unit? Was this just the capacitor's time to go? If I
replace the capacitor, am I just throwing money away?

Gary Brady
Austin, TX

Gary Brady wrote:

Not long ago, I made a shop fan from squirrel cage fan out of a
residential air handler. Last weekend was particularly hot, and I had
the fan running most of the day. When I went out to turn it off, the
fan was running but there was a puddle of oil underneath it. Now, or
course, it won't start. I assume the capacitor blew up or leaked.

Can a fan such as this be used for continuous use, or is it only suited
for on and off operation, as occurs in the normal cycling of an air
conditioning unit? Was this just the capacitor's time to go? If I
replace the capacitor, am I just throwing money away?

Don't know exactly what you mean by "residential air handler", but the
blower motor in a lot of home furnaces - including mine - runs 24/365.

I'd try a new capacitor.

Tove

Tove Momerathsson wrote:

Gary Brady wrote:

Not long ago, I made a shop fan from squirrel cage fan out of a
residential air handler. Last weekend was particularly hot, and I had
the fan running most of the day. When I went out to turn it off, the
fan was running but there was a puddle of oil underneath it. Now, or
course, it won't start. I assume the capacitor blew up or leaked.

Can a fan such as this be used for continuous use, or is it only suited
for on and off operation, as occurs in the normal cycling of an air
conditioning unit? Was this just the capacitor's time to go? If I
replace the capacitor, am I just throwing money away?


Don't know exactly what you mean by "residential air handler", but the
blower motor in a lot of home furnaces - including mine - runs 24/365.

I'd try a new capacitor.

Second that, and while your hands are dirty see if there's any oil
reservoirs that might benefit from lube, if that motor doesn't have
sealed ball beatings.

I know my home's air handler motors use sleeve bearings, I had to press
a new bearing in one motor last year when I didn't think about oiling it
and it started squealing. The shaft didn't look perfect either, but it's
made it so far.

Out of sight, out of mind.

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

On Sat, 10 Sep 2005 19:39:14 GMT, Gary Brady
wrote:

Not long ago, I made a shop fan from squirrel cage fan out of a
residential air handler. Last weekend was particularly hot, and I had
the fan running most of the day. When I went out to turn it off, the
fan was running but there was a puddle of oil underneath it. Now, or
course, it won't start. I assume the capacitor blew up or leaked.

Can a fan such as this be used for continuous use, or is it only suited
for on and off operation, as occurs in the normal cycling of an air
conditioning unit? Was this just the capacitor's time to go? If I
replace the capacitor, am I just throwing money away?


The biggest mistake most people make when making one of these the
first time is that they fail to put a restriction in the outlet. These
fans are designed to run into a restricted outlet (the coils, and
ducting of the system). If you run one wide open on the outlet without
the restriction it tends to overload the motor since there's to much
air moving over the squirrel cage.


Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook/index.htm

I found this out when testing one of these blowers. It overheated unless the
airflow was restricted. I expected the motor load to decrease when the inlet
was restricted but was surprised that restricting the outlet had the same
effect.
Don Young
"Wayne Cook" wrote in message
...
On Sat, 10 Sep 2005 19:39:14 GMT, Gary Brady
wrote:

Not long ago, I made a shop fan from squirrel cage fan out of a
residential air handler. Last weekend was particularly hot, and I had
the fan running most of the day. When I went out to turn it off, the
fan was running but there was a puddle of oil underneath it. Now, or
course, it won't start. I assume the capacitor blew up or leaked.

Can a fan such as this be used for continuous use, or is it only suited
for on and off operation, as occurs in the normal cycling of an air
conditioning unit? Was this just the capacitor's time to go? If I
replace the capacitor, am I just throwing money away?


The biggest mistake most people make when making one of these the
first time is that they fail to put a restriction in the outlet. These
fans are designed to run into a restricted outlet (the coils, and
ducting of the system). If you run one wide open on the outlet without
the restriction it tends to overload the motor since there's to much
air moving over the squirrel cage.


Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook/index.htm

Don Young wrote:
I found this out when testing one of these blowers. It overheated unless the
airflow was restricted. I expected the motor load to decrease when the inlet
was restricted but was surprised that restricting the outlet had the same
effect.
Don Young
"Wayne Cook" wrote in message
...

The biggest mistake most people make when making one of these the
first time is that they fail to put a restriction in the outlet. These
fans are designed to run into a restricted outlet (the coils, and
ducting of the system). If you run one wide open on the outlet without
the restriction it tends to overload the motor since there's to much
air moving over the squirrel cage.


Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook/index.htm


Thanks for the comments, guys. I noticed when I walked close to the
inlet, the noise from the blower changed somewhat. I'll try choking it
down a bit after the new capacitor. The fan motor, while wired up for a
single speed in the A/C handler, has four speeds. I wired it up through
a scrounged 4 position switch and now have four speeds. The highest
actually blows so hard that the fan moves backward on its rollers, so I
can't use the highest speed.


Gary Brady
Austin, TX