Motor temperature rise


New member
I see discussions about cooling the cyclone motor. In fact, the air going through the cyclone is very effective at cooling the motor.

Our system has a box around the top of the cyclone with 2" of noise abatement insulation on the inside. The cone of the cyclone is exposed. See the attached photo. The filters are in a separate noise abatement box at ceiling height. The air in vented, at the right in the photo, up through the dropped ceiling. We chose this configuration because we were very limited in floor space.

The temperature rise at the case of the motor is a few degrees after running for 10 minutes of so. When the cyclone is shut off the motor case temperature rises a few degrees more since the inside of the motor is hotter than the case and the heat flows out through the case.

If the cyclone is used for extended periods the room temperature of the shop increases because of all the motors which are running. Thus warmer air is flowing in from the ducts and the motor temperature goes up a few more degrees. The maximum motor temperature rise we have seen after repeated long term uses is about 10 degrees.

The noise level of the system is about 78db to 80db measured by the table saw about 10 feet from the cyclone. I can provide more information if someone is interested.



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I getting ready to insulate my cyclone in a small closet that will be easy to disassemble.
What type of insulation & frame work did you use?
Have you installed the filters sideways/horizontal?
Looks like a nice install in a tight space.
Installing cyclone

Installing cyclone

How you install depends very much on how much space you have. In our case, we have limited space. (It is a woodworking shop in a retirement community with a fair number of users.)

The best approach, to get minimum noise, is to enclose the whole machine including the filter. Since we didn't have much space, we mounted the filter horizontally close to the ceiling.

We also made an enclosure around the top part of the cyclone.

The enclosures were made of two layers of 3/4" MDF with a commercial sound proofing glue between the layers. Then we added two inches of sound proofing material on the inside of the boxes.

I will post some photos, drawings and noise measurements later. I will have to look for this information.

The air that goes through the cyclone doesn't directly cool the motor. The motor sits above the sealed impeller chamber. If the motor itself is completely enclosed without a flow of fresh air around the motor, the motor will experience a rise in temperature.

I'm not saying that the motor will trip off due to high temperature, but the inability to cool is a problem. I seem to recall very early Forum posting that talks about the use of bathroom exhaust fans to draw cooler air around the motor and exhaust it outside or into the shop.

My closet design has the motor exposed in the closet, with upper and lower air baffles. The idea is that as air leaves the filter stack, the closet becomes pressurized. Air can escape near the ceiling or the floor of the closet. The path of the air is at least 16 feet in either direction. The air flow is 60/40. 60 % of the air escapes through the ceiling baffle. The idea there is that 60% of the air will push the hottest air in the closet around the exposed motor and vent up. The 40% exit near the floor allows for some mixing of the air. It is all theory at this point. Some day I'll have the Myth Busters over to test some of my theories.

I have pictures in the gallery under Mark Ferraro.


The blower motor is mounted on a metal disk. The bottom side of the disk is exposed to the air flowing through the blower. The heat flows from the motor to the metal disk and is cooled by the air moving past. The metal disk acts as a heat sink like you sometimes see inside computers.

This is very effective. The blower moves a tremendous amount of air past the metal disk. I measured the motor temperature rise of our completely enclosed system. (I used an electronic thermometer. A cable connected the temperature probe on the motor to the control box outside.) The temperate rose a few degrees within the first few minutes and then leveled off. I have it written down in the shop, but it was small, less than 10 degrees if I remember correctly.

Other ways of cooling would be very ineffective compared to what the blower air does.

When the cyclone is stopped the temperature went up a few more degrees due the heat stored in the motor. It was no longer being cooled by the airflow.

I don't doubt your results.

I'm just having trouble visualizing the air flow. If the exhaust from the filters flows past the motor on the way to exiting back into your shop or to the outside, I can believe that airflow is helping to cool the motor.

I'm no engineer so I have no opinion on the concept that your metal disk acts like a heat sink. To act like a heat sink I believe the metal disk would have to be in direct contact with the metal housing of the motor and there would have to be a temperature differential for heat to travel from the hot motor to the cooler air surrounding the motor assembly.

It would be interesting to know at what temperature the motor trips its thermal protection circuit breaker.
Is it ok to install the filters horizontally like VermontDale did? I hadn't considered that orientation before.
To be certain, you might want to contact Wynn Environmental directly and ask them. I would think that they will say that it is okay as long as you seal the connections -- I've seen them mounted in series or side-by-side in vertical mode, and horizontally. Here is a link to their Cyclone filter webpage; their address and phone number is at the bottom of this webpage.
My motor was over heating and would trip the reset button. To avoid this problem I put a box fan on the floor of the dust closet and aimed it up. I use a remote switch to turn the box fan on when I turn on the DC. Problem solved.