Converting 3 Phase compressor to 1 Phase - Wiring Help Please

[SSINNOVATIONS]

Hi,

I was wondering if anyone can help me figure out how to wire a 1 phase motor on my compressor. It is an ingersoll rand T30 that came with a 3-phase 5hp motor. I have purchased a used single phase but am totally confused on the wiring. The compressor has a pressure switch and a magnetic starter attached. Any help would be greatly appreciated@@

 

[rockwithjason]

follow the bottom wiring diagram on the cover. your motor only has two leads and they connect to the load side of the over load relay. if the pressure switch and such worked before the change out then don't mess with it. you will have to add the jumper in the diagram that connects the a phase terminal on the load side of the overload relay to the b phase terminal on the line side of the contactor

 

[A_Pmech]

To begin with, that starter and overload will not support a 5HP single-phase motor.

You'll have to purchase a new starter. A NEMA size 1-1/2 or size 2 should work.

Being that it is only 5HP, you may be able to use a pressure switch alone if the motor has built-in thermal overload protection. I believe 5HP rated pressure switches are available.

 

[SSINNOVATIONS]

Being that it is only 5HP, you may be able to use a pressure switch alone if the motor has built-in thermal overload protection. I believe 5HP rated pressure switches are available.

If I understand you correctly I can eliminate the mag starter and wire directly to an appropriate pressure switch? Will this one work? http://www.ebay.com/itm/ingersoll-r...ultDomain_0&hash=item27c43addc3#ht_500wt_1202 It appears to be rated for 5HP.

Thank you so much for the help here guys, I really appreciate it!

 

[A_Pmech]

If that switch is rated for 5HP single-phase then yes, that should do the trick.

 

[SSINNOVATIONS]

So I found a pressure switch that can handle single phase 5hp but it's about the same price as a new mag starter for the unit.

If I purchase a new starter can I reuse the existing pressure switch? The switch is a square D with 2-pole HP rating of 2hp at 230v single phase.

 

[Norcal]

So I found a pressure switch that can handle single phase 5hp but it's about the same price as a new mag starter for the unit.

If I purchase a new starter can I reuse the existing pressure switch? The switch is a square D with 2-pole HP rating of 2hp at 230v single phase.

W/ a mag starter, all the pressure switch is seeing is the load of the coil of the starter, it's a non issue.

 

[SSINNOVATIONS]

Perfect! Thank you!!

 

[1500hd]

You could also remove just the overload and use only the contactor if it rated for a 5hp motor. This is if the 1 phase motor as a built in thermal overload.