Electric air compressor and generator

[mad welder 4]

I found the simplest, cheapest, one step, fairly idiot proof method to reduce starting amps on a 2 pole motor.
I was at tractor supply and found a 5/8 shaft, 3.2 inch go cart clutch on the clearance rack for $25 and figured why the hell not.
So I bought it and today I stuck that go cart clutch on my 2.5 horse 2 pole motor. It had 3.5 inch pulley, the go cart clutch is 3.2 inches, close enough.
The go cart clutch lowed starting amps from 47 amps to 24 amps. Which is very close to what the motor draws when unbelted from the compressor.

It looks like these go cart clutches are normally $50 to $60. So I was wrong about the simplest way to reduce starting amps being a 4 pole motor. Because a decent 2hp 4 pole motor is $200 to $300.

[MinnesotaDave]

If I understand correctly, the gocart clutch lets the motor "get going" and maybe even slips a little upon engagement - this lets the motor actually start spinning a decent speed before it has to drive the air pump.

Sounds like an excellent solution with no electronic time delay required.

I wonder how many starts the clutch will allow before maintenance is needed?

[mad welder 4]

I know the go cart clutch will last a long time even in a go cart application where kids will ride the clutch a lot to reduce speed, burning the paint off the clutch.
Even after 3 compressor starts back to back the clutch wasn't even starting to warm up.
I think the service time would be better measured in years rather than number of motor starts.

[MinnesotaDave]

Sounds like a great solution to me - nice job!

[mad welder 4]

I tried another combination.
I took my 2hp 4 pole motor which just happened to have a foot plate and C face, put a dayton electromagnetic clutch on it.
When I run the motor up to speed and apply power to the clutch with the motor going full speed the motor only surges up to 7 amps.

The go cart clutch works really well, but it adds 10 to 20% to your free spin starting amps.
The electromagnetic clutch allows for true free spin starting.
So my 2hp 4 pole powered compressor with electromagnetic clutch will have the same or less starting amps than my 1hp 4 pole compressor with go cart clutch.

I think just the go cart clutch will tame the start up on most air compressor and generator combos and you will be fine running just a compressor off your generator.
But if you want to run more stuff off your generator along with the air compressor or a second air compressor more advanced soft starting will be needed.

[Farmerboy]

is the compressor on 120 volt or 240 volt, running on a generator it is best to have the set up on 240 so both sides of the generator are pulling it not just one side of it,

putting a constant run unloader on the air compressor will help as the motor can run continuous and the unloader will pop on and off to fill the tank, once it is started it will only pull the run amps, as the motor will keep running, and not start and stop,

or go with a gas engine air compressor, and problem is solved,

[mla2ofus]

I like the setup I made to run the compressor off the Wisconsin crankshaft on my old Hobart. It supplies all the air I need for the air hammer and needle gun.
Mike

[mad welder 4]

All my 1hp and larger air compressors are 240v now.
I am making my electric air compressors generator friendly as a backup to my 5hp gasoline air compressor in case it breaks down or for when I need more air than it can provide.

They have magnetic motor starters and I'm going to add a time off delay so the compressor motor doesn't go from full amps at shut off to zero. I can set the time off delay for up to a minute so during times of heavy use the motor may not turn off.
This pneumatic unloader reduces generator surging.

[buck]

if you put a small tank inline before your main tank, then a bleeder valve on the small tank, when the compressor stops the little tank will bleed off so that on restart, it will start to a zero pressure state, you will need a check valve between the small tank and master tank, on lots of the older compressors the check valve is already in there, youre just basically making the bled line larger in volumn,, buck

[mad welder 4]

I have an electronic unloader solenoid and a long heat exchanger tube before the check valve.

[mad welder 4]

Over a year later and both setups, the electromagnetic clutch and go cart clutch are still working perfectly.

[Oscar]

pics!