I want to wire a single phase 5 hp motor to 220v in the breaker box?

Question

i just don't know how the wires are supposed to run from the breaker box to the pressure switch. how thick the wire needs to be, and how the proper way to pass inspection is. when i had it wired up to the box the motor just bogged down after it built up so much pressure and then shut off. can anyone help without having to hire an electrician?

Answer 1

You mention passing inspection. What did your inspector say? If it is really a 5hp motor (not a marketing 'hp' a lot of appliances have), you'll need at least 8 AWG wire. If you are going a long distance you might need larger for voltage drop. That is a good size motor, and where I am the power company would want to know about it. What size breaker did you connect with to start?

Answer 2

If this is a single phase motor, you will need to have a capacitor wired in as well - unless it is already built into the motor.

5HP motor should consume about 20 amps at 220 volts. Upon startup, it can spike 2 to 3 times of peak current for very brief moment.

The exact wire size depends on the distance you must travel. It'll probably be around 10 or 12 guage. It could be more, depending on the exact installation requirements. The wire size changes by variety of factors beyond simple current requirements.

We are talking about heavy current here. I suggest you hire a qualified electrician to set this up for you. You'll also need to supply the ground, and depending on code, you'll also need a quick disconnect by the motor.

If this is a water pump type usage, the pressure switch is supposed to cut-off the current when reaching the rated pressure. If the motor is bogging down before this point, you have a problem. If the motor is going beyond this point and bogging down, you have it miswired.

Answer 3

I'd recommend contacting the manufacture of the motor to see what they would suggest. or go to the manufacture's website and look up the specs of the motor and see what is recommended there. best bet is always goto the source first if you're not wanting to hire an electrician.

Answer 4

i don't know