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Old 03-01-17, 05:28 PM   #24
oil pan 4
Land owner
Join Date: Nov 2012
Location: NM
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Turns out the cheapest most effective way to reduce start up inrush was sitting in front of me the whole time.
I put the gocart clutch on my 2.5hp 2pole compressor. I knew it was going to need a smaller belt. The cart clutch is a 3.2 inch pulley and the solid pulley I had on there was a 4 inch. I had a slightly smaller belt, but it wasn't small enough.
The original belt was way too big and I didn't have enough adjustment built in to my design to take out the slack, the next size smaller belt was just too small with the motor adjusted all the way in. I finely got around to taking both belts to the store and selecting a size between the 2.

The results are that the motor which had a start up inrush of 45 amps is now down to 23 amps with the smaller clutch pulley.
Now if I welded on a bigger pulley added mass and lowered the mechanical advantage the motor has on the compressor even further with a bigger pulley it might peak at 25 amps.
Still down 20 amps from the original inrush is amazing.
I may even be able to use resistor start to further lower inrush if needed.
But I'm replacing this 2.5hp 2pole motor with a 2hp 4pole and electromagnetic clutch. They're already on the way.
I should say the magnetic clutch is already here, just waiting on the motor.
The end?
No not even close I still have a 3 phase 4pole motor on an ABB drive to get going and the 4pole electromagnetic clutch to make happen.
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