O.T. 4 Speed 110v Motor Question.

I want to use this motor for a filter, questions are.
Install sheet says turn control knob fully clockwise,if desired low speed is not achieved adjust the switch till it gives you desired low speed, what is the low speed of this motor supposed to be ?
Then rotate switch counter clockwise to it will give you the max speed, what is the max speed? 1100 RPM?
And how slow can this motor be run before you cook it?
Its wired exactly like the photo. Motor Control Switch is rated for 10 amps.
Also the control switch is warm when I run it, is this normal?
Thanks

redlee said:

I want to use this motor for a filter, questions are.
Install sheet says turn control knob fully clockwise,if desired low speed is not achieved adjust the switch till it gives you desired low speed, what is the low speed of this motor supposed to be ?
Then rotate switch counter clockwise to it will give you the max speed, what is the max speed? 1100 RPM?
And how slow can this motor be run before you cook it?
Its wired exactly like the photo. Motor Control Switch is rated for 10 amps.
Also the control switch is warm when I run it, is this normal?
ThanksView attachment 216004View attachment 216005View attachment 216006

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The only ones I've used like it have been on kitchen downdraft exhaust fans.

If Emerson's pubs are not explanatory, try Grainger's for the Dayton they are sure to have as a replacement for Emerson et al.

And yes, most variable controls get "at least" warmish.

If your filtering air/dust, this one or a dozen similar should do.

If liquids, I tend to use 12 VDC pump/motor combos for adjustable, 1-P, single fixed-speed and valving otherwise. Simplifies life a tad.

Ive tried to find specs, but it eludes me.

Notice that it is an "air over" motor. That means it was made for fan applications, where the fan would cool it. if there is no fan, it may have to be de-rated to a lower power for long term operation.

It also appears to be a PSC motor, possibly intended to find its own speed against a varying load, such as a fan or a pump. If the load is not varying with speed, it may not have the speeds you think you will get.

Its installed in a squirrel cage fan, Im using it for a dust filter connected to a Motor Control Switch.
Speed is controlled via the switch. I can turn the switch down and bring the motor almost to 0 RPM.
Im trying to find the slowest speed the motor will handle so I can adjust the switch accordingly.

Are you using a switch to the different windings, or are you using a triac type motor control? It sounds as if you may be using the motor control.

The motor control will make the motor go probably as low as the trigger circuit in the control will let you go.

If you used the 4 switched speed wires on the motor, you would get 4 "fixed" speeds.

Either way you will still have the potential cooling problem at or near full speed.

redlee said:

Its installed in a squirrel cage fan, Im using it for a dust filter connected to a Motor Control Switch.
Speed is controlled via the switch. I can turn the switch down and bring the motor almost to 0 RPM.
Im trying to find the slowest speed the motor will handle so I can adjust the switch accordingly.

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Pointless exercise.

The squirrel-cage blower effectiveness drops-off to useless well before your motor goes too slow. The makers mated motor & blower-wheel size and geometry that worked economically for "many" sizes and applications. Select the most appropriate size and features for your needs. Run it as designed and supplied - "factory" settings. Go do something more important.

It was not their first rodeo by several ten of millions of units, so it is baffling that you expect to know or discover something they have missed, lo the past 150-odd years.

I had this kind of situation with an air conditioner. The unit was originally installed in a locomotive with air through the evaporator from a fan elsewhere. I mounted a squirrel cage blower salvaged from a furnace and controlled it with a Variac, nice variable amplitude real AC. I could set the airflow anywhere I wanted it, from barely turning to full speed. For a given power setting, the speed would rise until drag equaled torque. Get a Variac rated for the max amps and set it to whatever suits you. Even at the lowest speed, where the current is lowest and so is the airflow, there will still be enough air to dissipate the reduced heat.

Bill

Monarchist said:

Pointless exercise.



It was not their first rodeo by several ten of millions of units, so it is baffling that you expect to know or discover something they have missed, lo the past 150-odd years.

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Not trying to ! Just looking for some input from people in the know about how slow I can turn this motor-fan assy. without frying it.
Ive tried looking it up - cant find it. Not trying to reinvent the wheel, just looking for info. Thats it.

redlee said:

Not trying to ! Just looking for some input from people in the know about how slow I can turn this motor-fan assy. without frying it.
Ive tried looking it up - cant find it. Not trying to reinvent the wheel, just looking for info. Thats it.

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Looking up thermistor cut-out temp values commonly stocked as repair parts, plus use of a temp probe or sensing "gun", a few man-days worth of screwing about, and you can FIND a number.

But "why"?

The "examples" for what must be considered when a motor (AC OR DC) must be run really slow already appear all around us.

- one is high "pole" count ceiling fans. Low power for their size, they can dissipate heat well, too.

- another is "gearmotors". Can't run the motor slow enough, gear it down, right in the same housing.

- and then there are motors that may have to sit at or near "stall" for long hours to hold tension for some process as if they were an infinite spring or such, then ramp-up to high speed to move the load.

Here we find "blower duty" motors, with a second motor running fast perched atop them and forcing serious amounts of cooling air through the primary motor.

Trying to get the performance or benefits of any of those common and long, long, proven solutions from an ORDINARY motor and marginal controller is the part I called "pointless".

Most especially on an extractor, filter, collector, "mover" of dust or such where the dynamics of the "fluid" flow are not linear, either.

One of the more useful approaches, BTW, can be found on the "variable power" residential vacuum cleaners (ours are Samsung).

A slide control right in the handgrip adjusts motor speed // vacuum strength so it can do a "heavy" pickup task - or be turned-down to where it won't try to ingest and choke on thin curtains.

No matter what brand is on those, you can bet that there was a bit of engineering and testing invested in getting them to do the do and...... last a while, too!



You can embark on some fractional exercise at reinventing some subset of all that wheel, "alone, and in the dark", as they say.

Cheaper to respect what that motor & control maker shipped as best they dared do without creating a warranty-coverage monster... then seek some other combo more appropriate to your needs as-built if that isn't a good enough match. No shortage of choices. You aren't the first entity with a need.

If your using a squirrel cage, I would use step pulleys rather then a speed control. As others have said, the squirrel cage won't do anything at half motor rpm

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and

I am not a motor expert, but from what I can see, you have a motor that is built as a four speed device. It has one common wire (white) and four different colored wires, ONE for each of the four speeds. It is intended to be run with a single pole, four pole (five poles for off) switch which connects only ONE of those four speed control wires to the line at a time. Thus the full, 115 VAC is applied to one of the four wires for the selected speed.

The motor speed control that you are showing is intended to be used with a motor that has only ONE native speed: only ONE wire connection arrangement, not four.

I do not know if they can be made to work together, but these two devices (motor and speed control) are not intended to be used together. The motor should have a simple switch to control it's speed while the controller you have should have a single speed motor. That was the intent of the designers. As I said, I am not an expert in this so I can't say if they can be made to work together. But you do have some genuine concerns. The motor could overheat. Possible something else could go wrong. I just don't know. If I had that motor, I would look for a four speed, motor control SWITCH. That switch would have five positions: Off, Low, MedLow, MedHi, and High. It would have five wires or terminals. And it would be rated for service with a motor of 1/3 Hp and 115 VAC. Take that speed control back or save it for another project.

Oh, on that speed control, when you can read the righted instructions you see that warm fins are a normal operating condition.

There is an old rule of thumb in electricity/electronics: if you can put your hand on it and keep it there, then it is not too hot. I have found this to be accurate over many generations of experience.

True, side story about that. I once had to use that rule of thumb on a power transistor in a power supply. I thought it was getting too hot so I put my thumb on it. I quickly had to pull it back and it left a finger print in the solder coated exterior of that transistor. I quickly turned it off, found, and fixed the problem. But my thumb print remained in the solder coating on the transistor, which was still OK and gave many more years of service. That "Rule of Thumb", literally worked. And my thumb was sore, but not badly burned.

What EPAIII said. "Purchasing Agent expertise" will do as well as Engineering on these critters.

Just browse Grainger/Zorro and find many of each. Read the specs and intended application data.

EPAIII said:

There is an old rule of thumb in electricity/electronics: if you can put your hand on it and keep it there, then it is not too hot. I have found this to be accurate over many generations of experience.

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As with any "rule of thumb" there are odd exceptions.

Y'know that "old copper penny" red-brown coloured Copper Oxide so desireable on a brushed motor's commutator?

Happens to have just the right combination of lubricity and electrical conductivity to provide the best and longest brush life as well as keeping the motor running sweetly.

And.. it forms best and lasts longest only in a narrow range of temps about 10 to 25 degrees ABOVE the boiling point of water.

Or so sayeth Reliance and their research lab. At 300 + VDC on my motors, I'm inclined to just take their word for that..

As usual, a simple question is flogged to death. The only circumstance where he is likely to overload the motor is using the blower without ducting supplying back pressure. Running at lower voltage will not cause a problem and his motor doesn't have a commutator. Get a Variac and quit worrying.

Bill

9100 said:

As usual, a simple question is flogged to death. The only circumstance where he is likely to overload the motor is using the blower without ducting supplying back pressure. Running at lower voltage will not cause a problem and his motor doesn't have a commutator. Get a Variac and quit worrying.

Bill

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Not their usual gig, but the local fire department went door to door a few months back. Handed us each a sheet of paper explaining that it was an ordinary attic vent fan motor running too slow from wear, neglect, and accumulated debris that had been found to be the cause of the fire that burnt-up our neighbour's home, and that the rest of us should check our ones.

Months on, they are done hauling away debris, but not done with the rebuild.

"Impedance protected" isn't alway good enough.

I have a Variac.

I don't use it for these motors.

Worry is not always a bad thing.

We do not, for example, know whether the material the OP is pushing around and filtering is flammable or inert...

I want to just make a simple box with air filters to filter fine wood dust from my shop air that my dust collector misses.
I looked up Variac Transformers and from what I see they can be adjusted down to zero also.
Thanks for all the advice, Im going with a single speed motor.

redlee said:

fine wood dust from my shop air that my dust collector misses.

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In general, not only flammable, sometimes explosively so, wood dust can be.

If you are only chasing what a proper dust collector has MISSED, you may not have a lot of risk.

I cheated. Bought two of these, used, and at a small fraction of their new price, from another PM member as he was downsizing a shop:

https://www.microaironline.com/media/L2244.pdf

Read the specs. Motor has two speeds only.

Check the filter prices. What you are trying to do is not all that easy to do really WELL, but neither is it terribly costly to get real improvement. Go Ogle "shop air filter". There are MANY smaller units on the market.

I don't NEED the full capability of my two, so plan to "cheat" a bit more and only partially populate the first-line filter housings. Given they'll take a common size of the same ones used for home HVAC, stacked "up to" four-deep, the annual filter cost is minimal.

If you want to protect the shop air quality more effectively? Go to the source of the dust. Perhaps a second dust collector ELSE clever hose & ducting to more places so fewer particles escape at-source and you don't HAVE to chase the "escapees" as hard.