Furnace blower into garage shop fan?

[Oren]

<http://s.ecrater.com/stores/136988/4b04f808b9c5f_136988n.jpg>

Thanks to everyone for the replies. The unit came from my home when I
had my entire HVAC unit replaced. I just removed the blower for use in
the garage. It worked fine - not a curbside picking.

I'll follow all the suggestions, measure amps, clean, cover the side,
etc....

Thanks again.

 

[Bob F]

I'm down with the above. If 25ft of 12 gauge is getting
hot, something isn't right. Assuming of course this is a
typical home furnace blower. They only typically run a
15 amp circuit to the furnace, which means 14 gauge
should be plenty.

I've never seen a home furnace fan that needed more than single digit amps.

 

[jcmil2]

I'm converting a HVAC furnace blower fan (c1997 model) into a garage shopfan. Salvage from my house. There are no markings, labels, etc., on the motor for information. I know nothing about the motor other than four speeds.Pic sample: (like this) <http://s.ecrater.com/stores/136988/4b04f808b9c5f_136988n.jpg> The black wire is high speed, the blue wire is low-high speed.The red and orange wires are high-low or low speed (have not yet connected/checked). The high speed (black) gets hot as does the extension cord plugs and the metal cowling. Putting bigger gauge cords on I still get heat on the cord, 12 gauge (25'). Same with the blue wire, but not as hot (metal cowling cool) or as much heat on the cord. My next try is the high-low speed,same 12 gauge extension cord (25'). Then try the other speed, low, on the same cord. The motor has a start capacitor; the motor runs fine. Heat on the cord is what I want to eliminate. Any thought on using the high speed without the heat problem? If I have to, I can settle for the lowest speed, butprefer the higher speed (desert hot garage). Ideas and help appreciated.

I have an old fan out of a Coleman furnace and these are the wires: red andorange coming out of the motor itself (used to go to a Molex plug) and a black and yellow coming out of a speed contol box but not otherwise connected to the motor (also used to go to the Molex plug.) Any clues on how to wire this dang thing up? Thanks...

 

[micky]

If I have to, I can settle for the lowest speed, but prefer the higher speed (desert hot garage). Ideas and help appreciated.

I have an old fan out of a Coleman furnace and these are the wires: red and orange coming out of the motor itself (used to go to a Molex plug) and a black and yellow coming out of a speed contol box but not otherwise connected to the motor (also used to go to the Molex plug.) Any clues on how to wire this dang thing up? Thanks...

You may be able to figure it out with an ohmmeter. Measure all
12 resistances, between every pair of wires. Make a table and write
them all down.

If none of measurements are infinite, assume there is one winding.
Find the highest resistance, and assume those two leads are each at
one end of the winding. Now these are *wind*ings, so the
resistance they show to a direct current ohmmeter is not the same as
the inductive impedance they show to alaternating current. The
latter includes the resistance but is higher.

So with a 110 volt a big fan motor might use 10 or more amps, and ...I
don't remember, maybe,... might show 10 or fewer ohms to the ohmeter.
That might be wrong -- you'll know when you measure it --, but I'll
assume 10 for the rest of the process. (I'm not going to try to
measure inducitve impedance, when most people, including me, only have
a resistance ohmmeter. )

So if the black and for example, yelllow, have 10 ohms between them,
what does the black have with the red and orange. Maybe 3 and 4.2.
And what does the yellow have between it and the red and orange.
Maybe 7 and 5.8. So that the total of the two segments, black to
red (3) and red to yellow (7) = 10. the resistance of the whole
thing***. See three stars below.

I don't want to connect the 110 volts across either 3 or 4.2 ohms. It
might burn out the wiring, and it's much more likely the complement of
those numbers is a usable resistance. So I'd rather connect the
voltage accors 5.8 ohms and 7 ohms (and 10 ohms) The only color that
will do this, as this story went, is Yellow. So try all three of
those pairs, yellow and orange, 5.8, yellow and red, ;7, and yellow
and black, 10, and that should give you slow, medium, and fast.

If it does, hook up a rotary switch of some sort to control your fan.


***If it doesn't work this way, if the numbers don't add up quite
close to 10, then maybe there are two or three windings. Let me know
if that's t he case and I'll t hink about what to measure next .

Even if colors are not standardized, I thought the number of windings
was, and I'll have to look at my furnace diagram to see how many
windings that motor has. Hmmm. Maybe it doesn't say. (It might just
have a circle for moter, I thought my fan made too much noise (ran
too fast) so despite the schematic, I connected the common wire to
each of the other two speeds. Unfortunately, they were even faster,
just as the diagram said they would be.

 

[Paul Drahn]

? If I have to, I can settle for the lowest speed, but prefer the higher speed (desert hot garage). Ideas and help appreciated.

I have an old fan out of a Coleman furnace and these are the wires: red and orange coming out of the motor itself (used to go to a Molex plug) and a black and yellow coming out of a speed contol box but not otherwise connected to the motor (also used to go to the Molex plug.) Any clues on how to wire this dang thing up? Thanks...

I have the schematic from our Coleman heat/cool system. We have a 1982
mfg. home, so probably the same fan you have.

First, the capacitor is not a starting capacitor. It is a phase shift
capacitor that is always in the circuit. It will wear out and may need
to be replace occasionally.

the orange wire is common.

The yellow wire is heating speed.

The black wire is cooling speed.

The red wire is low speed.

The blue wire is medium-high speed.

Several years ago I retrieved a similar fan from the metal recycle bin
at the local transfer station. I welded up a frame to hold it and added
two wheels to move it. I bought a rotary switch on Ebay that I modified
to control the speed by switching power to each of the speed control
wires. It has an open position between each speed selection, so no two
wires are powered at the same time.

If you don't have a blue wire, then your fan is three speed.

If the motor doesn't seem to start really fast, replace the capacitor.

Good luck.

Paul

 

[WBCarson]

Furnace from around 97 went out. Wired up the fan to a cord. Using the blue and white from the fan. Properly grounded.
Fan starts fine, blows fine, wires dont get hot but the motor does. Very hot.

Possible i could have wired it wrong? Seems to me if i did it wouldnt work.