squirrel cage blower

[Bricklayer]

I found a box of 10 of these bad boys in my friends barn when we were cleaning it out. Looks like it will work on my evaporator I'm building. Dosnt have any cfm ratings on it or any stamps with motor info on it for that matter. It has 2 black wires and 1 green wire. Any ideas on how I should wire it. Can I run it variable speed on a dimmer switch?

[maple maniac65]

I found a box of 10 of these bad boys in my friends barn when we were cleaning it out. Looks like it will work on my evaporator I'm building. Dosnt have any cfm ratings on it or any stamps with motor info on it for that matter. It has 2 black wires and 1 green wire. Any ideas on how I should wire it. Can I run it variable speed on a dimmer switch?

If you have 10 of them why not run it on a dimmer switch. If it doesn't work you have nine more

[Bricklayer]

I don't have 10 of them. I'm sure I can grab another one if need be but I only took one. I'm assuming with the two black wires. If I screw up the wiring it will spin in reverse. Right?

[Biz]

Green is probably earth ground so black wires are power. AC motors will only run in one direction.

[Bricklayer]

So is it a Crap shoot which one is the proper hot wire? Will I blow the motor?

[sugarsand]

Do the black have any markings on them?

[1arch]

If the motor is rated 120 volts polarity is not an issue and as mentioned direction will not reverse. It is even possible it is 240.
If by chance it is a DC motor and 120 volts is applied to it you'll know pretty quick by the extreme speed followed by a bit of smoke.

[Bricklayer]

No. Just black

[Bricklayer]

Went and found one in the box with a stamp on the motor. And the fan assembly is made by torin.

[Bricklayer]

Better picture

[Ontario Ian]

120volts. green is probably ground and blacks are hot and neutral. that's how I would try it.

[maple flats]

What size evaporator are you building? At 1/30 HP that won't push enough air if the evaporator is very big. It should be OK for one up to maybe 2x4, possibly slightly larger for under fire air.

[Bricklayer]

2x6 is size of evaporator I'm building

[CharlieVT]

The black wires will be the line power. Polarity won't matter. Green is ground.
I wouldn't hesitate to just hook it up to bench test, but if you want to test the wiring, using a VOM set to resistance check for a continuity check would do it.
The green wire should be continous with the fan and motor housing.
The black wires will be continuous with eachother but not with the green wire.

I'd suggest going back to your friend's barn and grabbing a second blower. Take a look at the blower image in Bascom's online catalog. Two motors:

https://www.bascommaple.com/category/forced_draft_units/

Having too much air and then throttling it back with a speed control or intake control gives you more fire control than having not quite enough blower.

I'd use a blower control like this:
http://www.zoro.com/fantech-speed-control-115v-5-amp-wc-15/i/G4735367/?gclid=Cj0KEQjwqZKxBRDBkNmLt9DejNgBEiQAq8XWPmTsHBc 38hfXicqekTOjUiYVe4_1IQzluqgsV8Y7IGkaAivj8P8HAQ&gclsrc=aw.ds

You could even hook up two blowers to one speed controller as long as you don't exceed the amperage rating of the controller.

Or you could build a mechanical damper to restrict the blowers intake.

[maple flats]

Based on the output of 2 similar blowers and comparing the amps vs CFM, That likely moves about 100 CFM @ 0.0 static pressure (no back pressure). I base that on comparing the Dayton 4c443 and 4c446 blowers. The 4c443 uses .95A and moves 70 CFM @ 0.0 SP while the 4c446 uses 1.54A at o SP. Both are on 115V. If there is a back pressure the 4c446 drops to 114 CFM at .5" SP, which is not much back pressure.
For a 2x6, if you can get another blower, you may want to run them in tandom. Then, to adjust the flow, just attach a flat metal cover over the air inlet, using just 1 screw. Adjust the screw tension so the cover can be moved, but stays where you set it. Then you will have full adjustability up to the fans' potential.

[Bricklayer]

I put a plug on it and it works good nice and quiet, I will go get another one and do as you said any pictures exist of the damper you are talking about I kind of understand that but cant picture it. and when I bring it into the arch should I connect it to a manifold under the gratesor just have it blow in from under the fire?

[CharlieVT]

The intake of the blower is a circular opening. Find a circular disk of metal (I've seen the top of a large tin can used) that is slightly larger than the intake opening on the blower. Using one sheet metal screw, attach the metal disk over the blower intake so that it completely covers the intake. If you pivot the metal cover on the sheet metal screw it will create a cresent shaped opening. The more you pivot the metal cover, the bigger the opening and more air.

Someone will probably post a picture. I don't use that kind of damper.

As far as a manifold, I think that depends on the kind of grates you have. If you have grates with lots of openings, you may get uneven distribution of the Air Under Fire (AUF). In that case a manifold would probably help to even out the fire.

I have grates that limit air flow and my AUF blower just enters the back of the arch under the grates. The air flow is pretty well distributed by the grates. I suspect that many folks who have added their own AUF do not have a manifold for the blower.

[Bricklayer]

When the duct enters the arch should I bring it to centre of the grates and 90 it up? I'm using 2" angle turned upwards. I've heard that's better and helps insulate the grates from warping.

[maple flats]

With that type of blower it is generally just blown in under the grates, either from the front or rear. Some even blow it from a side. Adding a duct system can help a little.
I blow in high pressure air (AUF, HP) and for that I blow into a 4" stove pipe, laid on the floor under the grates. In that I have 3 rows of 5/16" holes, one top center, and a row on each side aimed toward to outer edge of the grates. I don't think that or 2 of those would blow hard enough pressure to keep the air holes open with ash falling under the grates. With HP air, I only need to remove ash about 2-3x a season. At this time HP air would not be in the cards for you, the blower would cost too much, until you get a larger rig and start to grow your operation. At that time AUF and AOF increases efficiency but at the expense of a pricey HP blower, not just a bigger squirrel cage blower.

[Bricklayer]

Thanks for the info. I might eventually try auf/aof but I'm sure it will be a few years away. I've only got 100 taps. Am going to try the 2 blowers in tandem. See how it goes. I have a tinsmith I know building me a duct for the two. With dampers installed.

[wiam]

It is easier on the blower to put a damper on the intake instead of in the duct after.

[maple flats]

Absolutely correct.
When I was in the OWB business back in the 80's & 90's I bought Dayton blowers that had the tear drop inlet damper on them, I see they are not sold that way now. Easy to make, and better than buying a rheostat or whatever for adjusting the RPM's. You could also just have the tin shop cut a round circle about 1" larger than the inlet hole, using galv. ranging from about 14-18 ga. Thinner gets bent too easily.

[sugarsand]

On our previous evaporator, the blower was controlled by the swinging cover over the intake. Fan speed would increase as the hole was covered more to a point. The motor seemed to run faster under more load. Our present arch, we put twin blowers that operate with one motor with a long shaft. These blowers wont work by restricting the air opening, we wired them to a two speed switch(high,off and low). What made the other blowers speed up when restricted?

Sugarsand

[CharlieVT]

On our previous evaporator, the blower was controlled by the swinging cover over the intake. Fan speed would increase as the hole was covered more to a point. The motor seemed to run faster under more load...what made the...blowers speed up when restricted?

Your premise that you are increasing the load with increasing the damper approaching full closure is incorrect. At some point, by reducing the intake further, you are decreasing the load on the fan blades.
With air entering the fan, the blades experience a load, having to push air molecules out the exhaust duct as they are replaced by air molecules entering. If you block the inlet, the fan blades will experience less load and therefore the motor will speed up. At some point with no new air entering the fan, the air molecules inside the fan housing are spinning around with the fan blade, being churned essentially, rather that being blown out the exhaust duct. As the air trapped in the blower housing gets up to the speed of the fan, it takes less effort for the motor to keep that air spinning around. The air churning around inside the housing has momentum and the fan has less work to do to keep it moving around in a circle. This is contrasted with slow moving air that enters the fan when the damper is open; that slow moving air has to be accelerated by the fan and pushed out the exhaust duct, the fan has more load under these conditions.

Note that under conditions where you are restricting the intake, you are moving less air even though the motor and attached fan may be turning faster.

[lpakiz]

For what it's worth, the same thing happens when you put your hand over the suction hose of your shop vac. The motor speeds up, because it has less air to move, thus less load. If you hooked up an amp gauge, the amps drawn would decrease.
Many centrifugal water pumps react the same way. This does not hold true for positive displacement water pumps, tho.

[sugarsand]

Got it, that makes sence now.

[Super Sapper]

Do not restrict the suction side of a water pump, it will cause cavitation and ruin the pump. Restricting the discharge of a centrifugal pump reduces the work load and amps needed but do not do this with a positive displacement (high pressure) or it can blow up.