Question Wiring a new compressor

[Dogman]

dogman-

yes, you can run a 3 phase motor on single (two phase) power. You need a phase converter. But for the compressor that starts and stops constantly, its not going to be much help, easy or cheap to build an automatic starter circuit. Look in the sticky on this page for designs. I have built a couple and like the fitch williams design.

transformers, phase converters and vfd - practical machinist - largest manufacturing technology forum on the web

how big a compressor motor?

You realize that to southern engineer any of these things, you are going to be spending some money, and probably as much as it would cost you to either run wire or run systems piping or hose to get it to there.

5 hp, And I know what your saying about the rewire the shop. I have a guy coming today to give me a price.

Here's what Im dealing with.

 

[DaveBen]

Technically there isn't. It is either single (one) phase or three phase. I understand how this works, but I am not sure I could explain it. If you have two phases, they MUST be 180° out of phase with each other which would cancel each other out. 360° divided by 2 = 180° out of phase. The 60 cycle sign waves would cancel each other out. 360° divided by 3 = 120 phase shift and this does not cancel out the other sign waves. Clear as mud.

Dave

 

[Dogman]

Technically there isn't. It is either single (one) phase or three phase. I understand how this works, but I am not sure I could explain it. If you have two phases, they MUST be 180° out of phase with each other which would cancel each other out. 360° divided by 2 = 180° out of phase. The 60 cycle sign waves would cancel each other out. 360° divided by 3 = 120 phase shift and this does not cancel out the other sign waves. Clear as mud.

Dave

OK now my head hurts.....

 

[Dogman]

Lets try it this way.... streight from the big power box.

phase 1 phase 2 phase 3 neutral ground
Leg (1) leg(2) leg (3)
120 V 240 V 120 V
all three total 480 V

 

[rammertide07]

Could you just change the motor that is on it?

 

[dpantazis]

If you have two phases, they MUST be 180° out of phase with each other which would cancel each other out. 360° divided by 2 = 180° out of phase.

that is not really correct.

with single phase service from the pole, you get 2 legs of 110V power that are 2 out of the 3 in the 360, or 120 degrees apart, not 180.

think about it. that is how/why we can combine neutrals.

 

[dpantazis]

Could you just change the motor that is on it?

$300-$600 for the motor and another $150 on the controls. its not worth it. by the time you get done swapping out the motor and the controls to single phase, you are going to drop as much if not more to pull the circuit.

 

[DaveBen]

that is not really correct.

with single phase service from the pole, you get 2 legs of 110V power that are 2 out of the 3 in the 360, or 120 degrees apart, not 180.

think about it. that is how/why we can combine neutrals.

Your math is not correct, either. But I know what you are talking about and you are right. You have the "Y" with the center neutral and each leg is 120° out of phase from the first one. End of this worthless topic. Do as dpantnzis says and get a new motor.

Dave

 

[JLDickmon]

you need a phase converter.

hop in your speeder, and run in to Tashi Station to get one..
watch the Sand People, and don't forget to swing by Obi-Wan's place on the way back..

Have those droids on the South Ridge before noon, or there'll be hell to pay..

 

[rammertide07]

$300-$600 for the motor and another $150 on the controls. its not worth it. by the time you get done swapping out the motor and the controls to single phase, you are going to drop as much if not more to pull the circuit.

Oh...yea I wasn't thinking lol. I'm use tripping over motors in the shop floor.