Generator won't power compressor....ideas?

[Boeing]

Steve,
Just so I'm clear here....I'm sure that there is a wiring diag on the wiring plate. It MAY be for 3 wires though, it's an older unit. With 4 wires I'm guessing that black is power, red is power, white will remain neutral and ground is ground.....
Now, you said that the added capacitor would go on the SAME banonets that the existing capacitor is on? BOTH...capacitors wired together? I do not remove the orig one? thanks

 

[Soundguy]

wired together as in parallel ( not series ), as in adding capacity.

that's why it would be a starting 'AID' capacitor. ie.. helper.

 

[Qapla]

Keep in mind that they call them a "hard start" capacitor for a reason. I would try to relieve the pressure from the head while in start mode before I sent additional "kick" to the motor. It just seems to me that if the compressor work fine from household power it does not need the added "hard start". What it needs is "relief" while in start mode.

 

[Soundguy]

would be eay to rig a manual unload for 0 start pressure...

 

[jenkinsph]

Steve,
Just so I'm clear here....I'm sure that there is a wiring diag on the wiring plate. It MAY be for 3 wires though, it's an older unit. With 4 wires I'm guessing that black is power, red is power, white will remain neutral and ground is ground.....

I don't think you need the white nuetral wire on an electric motor if wired for 240v. If it were an appliance with 120 and 240v circuits you would need it. You will need a ground and two hot wires. You will need to change up the existing wiring of the motor leads inside the junction box too.

 

[chim]

here.. i'll throw a bone.. root mean square is .707 of peak..

e=IR
P=IE

those are dc measurements and don't take into account for inductance vs resistance.. but it's 'horseshoes and thermonukes close'

and under 'perfect' non real worl conditions that don't take into account fractional losses.. a hp = 746w

the math puts it very close from there.. a 4hp peak listing drops you into somewhere in the 2.8 range...
convert to w = 2088
derive current = 17.4a

a very realistic #

I appreciate the bone and your patience, but your approach is totally bogus. The 17.4A is certainly not "very close" at nearly 8% off the target. As soon as I see someone posting on a non-electrical forum and throwing out terms they picked up at an adult ed evening course instead of real numbers that work, the flags go up. I don't know your background, but it doesn't appear to be in power. Don't feel badly. I couldn't design a pair of earbuds without more schooling.

 

[Boeing]

I'm getting there.....Steve, if I don't NEED the white neutral (which will be in the 10/3 wire from the 4 plug generator)....I can just clip it or cap it and connect the black/red and ground, RIGHT?
And.....unloading from Soundguy...."easy to rig a manual unload".....give me a suggestion. This is a belt driven unit. I wish I could rig a clutch or belt idler like auto Air Conditioners use??? I like the long coiled tube idea that was suggested early in this post; but now that I think about it, it would need a one way check valve at the tank or the tube would have the same backpressure that the tank has......hummm?

 

[DarkBlack]

I'm enjoying all this too I think one poster is confusing BS peak hp ratings with peak sine wave voltage-not the same.
Just think, elec motor are so predictable that they ae allowed to publish power based on the fuel they consume...electricity. Imagine if it was done that way with combustion engines. Instead of cheating with locked rotor amps, they would be putting in oversized jets in the carbs to run richer, so they could advertise more HP, based on fuel consumption. I'm surprised nobody engaged me on the mention of rotor slip? Go buy a "cummins tool sale" motorized tool that runs slow and heats up in seconds, and you'll have yourself an introduction into slip and why it matters.

 

[Qapla]

... I like the long coiled tube idea that was suggested early in this post; but now that I think about it, it would need a one way check valve at the tank or the tube would have the same backpressure that the tank has...

The compressor should have some sort of check valve built in (perhaps part of the relief valve) or the air would leak back/out of the head every time it turns off.

 

[Boeing]

Wouldn't that Compressor check valve be in the compressor itself PRIOR to the copper tube that was to be lengthened....per suggestion? Once the air is pushed out of the compressor it goes thru the copper line and into the tank. I can't see how LENGTHENING this tube will help anything without de-pressurizing that tube. What am I missing?