How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Mike Your Own Question
Mike, Master Electrician
Category: Electrical
Satisfied Customers: 1425
Experience:  Licensed Master Electrician - OnQ Certified Data Voice Audio Video Installer
Type Your Electrical Question Here...
Mike is online now
A new question is answered every 9 seconds

I need a quick help on wiring an electric motor (compressor)

Customer Question

I need a quick help on wiring an electric motor (compressor) to a starter. I have a Baldor 5 hp single phase motor, and a Dayton IEC 2UXW6 starter. And of course 220v at the wall, and a Lefoo LF10-1H pressure controller.
Right now I have the leads from the pressure switch wired to the starter at T1 and T2. And leads going to L1 and L2 from the 220v power source (not plugged up, obviously). It appears that the switch for the starter is on A2, so that part is fine.
1) I'm not sure what to do with A1. There's a green wire attached at the A1 label on the starter. It has a connector on the other end. There's a red wire zip tied to that one, connectors on both ends. Right now I have the A1 green going to T1. And the red simply jumpering L2 to T2. But that is just a guess on my part, and could be way off.
2) I planned to run the pressure switch from off the starter, and the motor from there. Is this correct, or is the A1 for running the pressure switch perhaps?
220v source --> L1, L2
T1, T2 --> pressure switch line terminal
pressure switch motor terminal --> motor
3) Just to double-check the Baldor motor. 5hp single phase 220v. There is a yellow fat wire, and a blue fat one. Yellow is 4, I'm assuming blue is 1 (can't find a label on it). Red is 8, black is 5. From the diagram it appears that I just connect 8 and 1 together with one lead from the 220v, and 5 and 4 with the other lead. I don't need this reversing, as it's for a compressor. Is this correct?
Much appreciate the help . . .
Submitted: 11 months ago.
Category: Electrical
Customer: replied 11 months ago.
I can take photos of the wiring diagrams on the motor and the starter if that helps. I just don't understand the one for the starter.
Customer: replied 11 months ago.
If this is too detailed for a basic answer, let me know and I'll upgrade it to "detailed" and pay.
Expert:  Steven Parent replied 11 months ago.

Hi there, thanks for choosing Just Answer. My name is ***** ***** will be happy to assist with your electrical questions.

Is the voltage of the coil 240V ? Would you like a toggle switch to control the compressor? Or just always have it run just through the pressure switch? I will attach a wiring diagram for you. Let me know how you make out.

Customer: replied 11 months ago.
Thanks very much, Steve. The diagram helps considerably. And I see that it includes running the pressure switch off of A1-A2 rather than in series after the starter as I had originally thought to do. My pressure switch does have a toggle on it, so no need for an external toggle - but thanks for the suggestion. I'm working on it now, and will get back to you . . . .
Customer: replied 11 months ago.
Here's a diagram of how I have the hookup working right now, based on your diagram. Can you give this a quick lookover and tell me if I've mistaken something?
Customer: replied 11 months ago.
Oops, mistake in my drawing, let me correct it and resend
Customer: replied 11 months ago.
No, no mistake - I just had to doublecheck the NO switch setup. I appreciate the help, and a quick lookover, and then I'll be all set if I've understood this correctly.
Expert:  Steven Parent replied 11 months ago.

Does your pressure switch on/off switch have terminals for external wiring?

Customer: replied 11 months ago.
No, it doesn't. Just the on / off switch with a lever that lifts the terminals when disengaged
Customer: replied 11 months ago.
If you'd recommend an external switch, I can certainly put on in.
Expert:  Steven Parent replied 11 months ago.

Is it just opening the contacts between LINE and MOTOR ? Or there are 2 terminals on the switch that it is operating?

Customer: replied 11 months ago.
opening between LINE and MOTOR. There are two terminals for each, for wiring normally without a starter - i.e. for the hot leads on 220v or hot and neutral on 110v. I'm not sure if that is what you're referring to . . .
Customer: replied 11 months ago.
In the photo, the top two terminals are LINE, and the bottom two are MOTOR. The brass lever on the left is what disconnects.
Expert:  Steven Parent replied 11 months ago.

Ok, thanks for the photo. So then the wiring between the ON/OFF switch and the N/O contact that you have in your drawing is not required. The switch will break contact and not allow the starter to pull in unless it is in the ON position and there is low pressure. Wire it up as such, and you will be good to go.