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Discussion Starter #1
Hello everyone,
I purchased a 5hp 80 gal Saylor Beall air compressor that needed rebuilt. It is finished now and I'm having trouble wiring it up. I have a schematic of what I'm trying to accomplish but I have added a few more things like a start/stop switch and hour meter. I have pics of everything I'm using so if anyone could help I would tremendously appreciate it! The motor is a Dayton 5hp 208-230V 25.5-24.0A single phase.
Thanks,




 

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A start-stop will require another relay with a 240 volt coil and different pushbuttons.

A basic on-off will need a single pole single throw switch. A basic light switch mounted in a single gang handy box will work. It simply connects in series with one of the pressure switch wires.

The hour meter will need to be 240 volts and it connects in parallel with the starter coil.

Rob
 

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If you don't understand controls and the type of contactor with coil you require, you shouldn't be installing this yourself.

Your wiring must be sized 1.25 X 28 (5hp SF 230V) = 35A (#10AWG Minimum)

The (possibly I'm CEC not NEC) up to 70A (2.5 X 28A) breaker you will use to protect the compressor will not properly protect the control wiring, so you may still require a control wiring transformer on top of everything you've already purchased, or just possibly fuse down on that wiring. Your hour meter is 120V yet your compressor is 240V, so you'll need to still provide yourself with a neutral to your setup.

As far as your control wiring is concerned, a basic switch in series with your pressure switch would be easier than what you have for start stop, provided your contactor has a 120V coil.

Anyways, be careful how you proceed with this project. You could be installing major code violations and a dangerous end product if not careful.
 

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Discussion Starter #4
Thanks guys,
OK, I found this diagram. It's a lot better explanation. Now I just need to wire the C400GK1 switch and hour meter into this.

 

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The hour meter won't work. You don't have a neutral for 120 volts. If you had a 240 volt hour meter you would connect it across T1 T3 where the motor is connected.
For a start stop switch I would just use a double pole 240 volt toggle on/off switch across the line from the breaker.
 
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