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DIY Harbor Freight Air Filter

You said this: "Getting the plane up to the desired speed required for flight (from 0mph) requires much more torque than maintaining that speed through the air. So load is decreased because the motor doesn’t need to work as hard just to overcome the drag/ friction of flight."

I was talking about air density at sea level vs. density at altitude. Something I deal with in my career. When air is denser, it creates more load on the propeller or turbine. I'm not talking about skin friction of the aircraft or any other drag losses, just the air pump (aka propeller or turbine).
 
First of all you are comparing a jet engine to an electric motor. Not the same thing. If you were a teacher, you should be fired.
Air is not always the load lol. Load is resistance to the motor. If the motor is pumping air as an output then yes, resistance in the air or restrictions to receiving air would increase the load. Sound like you need to do more research on this subject. Let me know when you have done that. I would love to continue this conversation then. ✌️
 
We are talking about types of air pumps, and your comment about firing me is not helpful. A turbine and propeller are types of air pumps. Regarding squirrel cage fans, restricting the air creates a partial vacuum condition. Fans in a vacuum spin really fast because the air load has been removed, and the motor no longer has a resistance load on it. Less air = less load = lower amperage requirements.
 
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I’m talking about an electric motor’s response to changes. If the motor is driving a fan and air flow is the desired output then when the air is restricted, the motor will react by increasing its speed which in turn increases the load on the motor. Btw, you were the one who brought up the teacher comment. If you don’t like my response, then maybe try not bringing it into the conversation.
 
If you decrease the load on a motor the RPM speeds up and amp draw goes down because the motor is receiving the same voltage. You might as well be arguing the Earth is flat at this point. Given I have provided all the links that you need to learn some basic principals, you are either unteachable, or you are trolling. Just realize that since I provided all of the links and actual testing and data from experts, you are no longer arguing with me, you are arguing that you are right and the experts are all wrong.
 
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Straight from the link.

The formulas indicate that an increase in power due to an increase in the service load requires a proportionate rise in the torque so it can match the load. This increased torque draws a bigger electrical current into the motor.

You argue the same voltage, but it’s amperage that is increasing. Lol you are fundamentally missing this. It’s all good bro. But this is not rocket science. Lol
 
You are missing the fact that restricting the air is reducing the load not increasing it. And amperage does increase with load, as you mentioned, but I mentioned voltage because that stays constant unless you are running a VFD.
 
You are reading too far into it. I’m talking about an electric motor’s physical reaction to changing conditions. The motor wants to spin at the designed rate of speed ALWAYS. If the motors job is to move a fan that pushes air molecules, you restrict air flow and you effectively increase the pressure inside that system. The motor has to work harder to over come the increased pressure in order to spin at the same rate of speed it was designed to. To increase the rate of speed, the motor draws in more amps to compensate for the air pressure increase. This is how a motor gets burned up.
Take this information to any subject matter experts you confer with. I really can’t break it down any further than that. You can either chose to believe it or not.
 
You actually wrote this: "If the motors job is to move a fan that pushes air molecules, you restrict air flow and you effectively increase the pressure inside that system."

That violates physics. It decreases pressure by creating a partial vacuum. The motor works less hard, RPM goes up proportionally to the decreasing load, amperage draw goes down. Because it has less air molecules to move, there is less drag on the fan. That's the facts Jack.

You actually want me to choose to accept your conspiracy theory on how electric fans work even after you viewed all those links from experts? That's not only naive, but delusional. I'm a man of science, not speculation.

An old saying comes to mind here, "You can lead a horse to water, but you can't make them drink". Best of luck with your critical thinking skills.
 
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You say less air molecules to move... but that is not true with a motor and fan. Remember it wants to spin at the same speed it was designed for. Same amount of air molecules.. just harder to move because you need more flow to get the same reaction. Restricting a motor in any way shape or form just makes it push harder and draw in more amps to overcome that resistance. Unless there is some sort of control device to regulate that. Remember the electric motor by itself always wants to move as fast as it is designed to. So there is never a case of moving less molecules unless you are controlling the motor with something such as a VFD.
 
Oh shit, decreasing is correct. Stupid statement there by me. Yes, it must compensate for the decrease in pressure. Good catch!
 
So wrong. You are clearly not visiting those links I provided. Your mind is closed. Repeating the same fallacies over and over does not make them come true. Some of the stuff you say is right like '"Restricting a motor in any way shape or form just makes it push harder and draw in more amps to overcome that resistance." That is true. But your understanding of starving a fan of air is complete fallacy and opposite of what really occurs.

Here's the science in a nutshell. Read carefully: When a squirrel fan is completely unrestricted to flow, it is under the most resistance because it has the most amount of air to move. When it is fully restricted, it has the least resistance because it has the least amount of air to move. The motor has a harder time running the fan when it has the most air, and an easy time when it has the least air. I know it's totally counterintuitive, but it's true. Whether or not you choose to accept facts is up to you.
 
Yeah, not yet. Been typing and doing shit here at the same time. My bad bro. I will visit the links today. I understand what you are saying. It makes sense I know more about electric motors than I do about fluid dynamics. I don’t build rockets. Lol
Thanks for this conversation. I have learned a lot today. Hope We didn’t piss each other off too much. I would Like to continue talking on here after I read the links. I enjoy this type of banter. Sometime too much my wife says. Lol
 
I actually come from a maintenance background. I know a dirty filter makes the motor work harder and costs more in electric bills.
 
And if that’s the case... the pressure causes the motor to spin faster than designed you get a current back flow. And your motor becomes a Generator creating amperage, burning up the components.
 
I saw/read the links. Seems like the blower was designed for 9amps and was operating at 16 amps while unrestricted. This is conclusive of what you were saying. But the blower is designed to be restricted and not run unrestricted. That’s why I said unless it was designed to operate this way. Seems like it was designed specifically for restricted flow. Which is exactly what I was asking about in the beginning. Read comment #3.5 the answer to that statement is that the blower is designed for restricted flow. Confirms everything you posted plus eliminated my original concern.
 
Yeah. Seems like these motors were designed to drop amps on restricted flow. That is not the case with all motors though. Some are designed to maintain air flow and on those types, restriction to air flow causes that type of motor to over work and burn in an effort trying to maintain the proper air flow.
 
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The load drops, so the amps drop. Because all motors draw amps in direct relation to the load placed on them. The higher the load the higher the draw in amps. An unloaded motor will run at very low amps, and then when you stick it in gear, it will draw a bunch of amps. Those same principals work the same with a blower motor, but the air is the load, not gears or pulleys. You remove the air, you remove the load, and the motor has a real easy time of it.
 
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