Air compressor Motor

[RUSTY50]

Hi Fellas
I bought a 5hp compressor head from HF. I bought a 5hp 3 phase Motor off ebay. Do I need a magnetic starter for the motor or do I need anything or will it start when the pressure switch points close. Can any one help me out with this. Thanks RUSTY

[HayZee518]

A 5 hp motor draws about 15 amps on startup and drops to around 8 running. a magnetic starter with overload protection is necessary. the pressure switch connects into the coil that operates the starter. do you need a connection diagram for this?

[HayZee518]

Is your installation at a residence? at a business? do you have three phase power available? What follows is a connection diagram of a three phase magnetic starter on a three phase line. The motor will need three overload heaters for the magnetic starter. take the nameplate current and look on the cover of the magnetic. you will see a range of amperages. get three overloads as close to the nameplate current without going excessively over. This is to protect your motor should there be a bad bearing or something that might slow your motor down without burning up the motor. this magnetic is used at line voltages so be careful. most industrial starters now used - use a separate control circuit at either 24 volts or 120 volts ac.

[RUSTY50]

It is in my garage at home all I have is 220. 2 big wires on the main breaker and a common. ........RUSTY

[RUSTY50]

I'm not sure what you mean by 3 phase wiring in my house. The compressor is in my garage. My Main breaker box only has 2 large wires coming in to the main breaker and a common. I have 220 in my garage.

[RUSTY50]

Originally Posted by HayZee518

Is your installation at a residence? at a business? do you have three phase power available? What follows is a connection diagram of a three phase magnetic starter on a three phase line. The motor will need three overload heaters for the magnetic starter. take the nameplate current and look on the cover of the magnetic. you will see a range of amperages. get three overloads as close to the nameplate current without going excessively over. This is to protect your motor should there be a bad bearing or something that might slow your motor down without burning up the motor. this magnetic is used at line voltages so be careful. most industrial starters now used - use a separate control circuit at either 24 volts or 120 volts ac.

The compressor is in my garage at home. I have 220 in my garage. I'm not sure I know what you mean by three phase. I have two large wires (hot) coming into the main breaker and a common. RUSTY

[HayZee518]

OK, being your compressor is at home and you stated your bought a THREE PHASE MOTOR, normal service for a house is SINGLE PHASE. A single phase motor has four wires whereas a three phase motor has nine wires in the motor junction box. Give me all the motor data on the motor nameplate. i.e. volts, amps, frame no, hp, phase, insulation code etc. (how can I explain this easily......?) OK, your electric range at home runs on single phase AC, your electric dryer runs on single phase AC. A three phase AC motor will not run on SINGLE PHASE AC because it is missing one additional phase. If you bought a SINGLE PHASE motor from EBay then there'd be no problem. Jeez I wish this chat progrma was working - get back to me HayZee.

[HayZee518]

OK you said you got two fat black wires and a bare twisted ground coming off your service entrance. If you had three phase you'd have three fat black wires and a twisted bare ground.

[RUSTY50]

Originally Posted by HayZee518

OK, being your compressor is at home and you stated your bought a THREE PHASE MOTOR, normal service for a house is SINGLE PHASE. A single phase motor has four wires whereas a three phase motor has nine wires in the motor junction box. Give me all the motor data on the motor nameplate. i.e. volts, amps, frame no, hp, phase, insulation code etc. (how can I explain this easily......?) OK, your electric range at home runs on single phase AC, your electric dryer runs on single phase AC. A three phase AC motor will not run on SINGLE PHASE AC because it is missing one additional phase. If you bought a SINGLE PHASE motor from EBay then there'd be no problem. Jeez I wish this chat progrma was working - get back to me HayZee.

I don't know how to put pics on this site yet so here is the motor site. U.S. MOTORS (EMERSON MOTOR CO.) catalog #D5E2D Model# AD77 It says it will run on 220. ........RUSTY

[HayZee518]

Rusty I went to the Emerson site and brought up the specs on the motor. They are:
Catalog Number: D5E2D Model: AD77
Hp: 5 Phase: 3 Volts: 208-230/460 HZ: 60/50
RPM: 1760 Amps: 14-13.4/6.7
Insul Class: F SF: 1.15 SFA: 16-15/7.5
Max Ambient: 40 NEMA Frame: 184T Encl: DP Code: J
Shaft End Bearing: 6206-2Z-J/C3 Opp End Bearing: 6205-2Z-J/C3
NEMA Nom Eff: 87.5 Thermally Protected: N/A Type: FD
Because you are in a residential house, three phase power is NOT supplied to you. You have just purchased a big expensive boo-boo! To have three phase power at your house you would need to purchase a three phase converter which could run about a thousand dollars.