Need help building compressor

[JimLL]

I don't know if this group prefers long or short initial posts. I'll try for something in between...

I have 3 pieces - a "5 hp" two-lung compressor and a "5 hp" 2 capacitor motor from Harbor Freight and a big Champion TUV458 tank with "tatters" of controls left on it. The compressor and motor are missing, leaving whacked off armored cable leads dangling. It was once the primary compressor in a small garage.

My problem is that I can't find wiring diagrams for the setup. I can barely remember when I wasn't building something with motors, but this my first foray into the world of contactors/starters, altho I know their purpose, etc.

Surprisingly (to me) the motor leads are only 12 gauge. The wires to the pressure switch are 14 gauge and there is an additional cable from the top of the controller with 14 gauge leads. Line power?? 14 gauge?

The starter is:
GOULD A203B SIZE 0 ENCLOSED MOTOR STARTER W TRANSFORMER
* 20 AMP MAX OPEN / 18 AMP MAX ENCLOSED
* COIL - 120 V 60 Hz 110 V 50 Hz
* PRIMARY - 240 / 230 / 220 - 480 / 460 / 440
* SECONDARY - 120 / 115 / 110
ENCLOSURE - NEMA TYPE 1 ( INDOOR )

I pretty much "get" the general layout, but I'm totally lost how, in detail, to properly wire (rewire) this thing, assuming what I have will actually work.

I'd appreciate any directions or questions about it.

TIA

JimL

 

[Charles (in GA)]

What is the amp draw on the HF 5 hp motor? It may be low enough (probably not really a true 5 hp) that you can dispense with the motor starter, and switch the motor off a good pressure switch.

Charles

 

[Warrenator]

Get yourself a pressure switch off ebay, go down to a place where you can see properly setup 5 hp compressor and note the pressure relief line going to the pressure switch via a check valve mounted to the tank. Try hooking it all up temporarily with a v-belt and whatever pulleys you have, if the motor stalls or has a hard time you can switch to a smaller pulley on the compressor. Don't pump up the tank too high without a gauge and pressure relief valve and a means of auto shutoff.

Don't forget a pressure relief valve, make sure it matches your tank pressure for safety.

Compressors and tanks come in 2 stage high pressure (maybe 175 psi in the tank) and single stage lower pressure (maybe 125 psi in the tank) Make sure you use switches, pressure relief valves, and regulator to match your components since you are mixing and matching compressor and tank and switches.

I agree with the above poster, you can probably skip the magnetic starter. Not all 5 HP motors have them.

 

[JimLL]

What is the amp draw on the HF 5 hp motor?

Charles

Thanks. It doesn't show amps directly. It says 3.1KW. I guess at 230 VAC, even single phase, that would be within pressure switch range and OK at 12 gauge. One converter put it at under 14 amps.

What do you make of the "5 HP" label on the compressor itself? I certainly wouldn't put a 2 HP motor on it, but otherwise...

I still don't understand using a starter and 14 gauge on the old line wiring. Perhaps with 3 phase, but there is only red and black on it.

JimLL

 

[djd99]

Thanks. It doesn't show amps directly. It says 3.1KW. I guess at 230 VAC, even single phase, that would be within pressure switch range and OK at 12 gauge. One converter put it at under 14 amps.

What do you make of the "5 HP" label on the compressor itself? I certainly wouldn't put a 2 HP motor on it, but otherwise...

I still don't understand using a starter and 14 gauge on the old line wiring. Perhaps with 3 phase, but there is only red and black on it.

JimLL

Here's another question what size is the diameter of the shaft coming out of the 5hp? This really makes a difference in how many hp your motor really is, most likely being a hf 5hp it's not truely a 5hp witch would not require a magnetic starter. Just buy a 20 amp switch from home depot.

Those 5hp motors from hf is more like a 3hp with a 5hp label. Now if you can find a farm duty 5hp with a 1 1/8 shaft now you have a motor that requires a magnetic starter.

 

[JimLL]

Those 5hp motors from hf is more like a 3hp with a 5hp label. Now if you can find a farm duty 5hp with a 1 1/8 shaft now you have a motor that requires a magnetic starter.

One converter puts the HP figure at 4.1 HP, based on the 3.1KW label. The shaft is 5/8 inch. Of course the issue in matching is pulley size. But I doubt the Chinese put a lot of stock in any need for bigger shafts. The motor is labeled as being for a compressor and says "continuous duty" whatever that actually means. And I suspect 4 HP will be enough to do the job, since it won't get a lot of use in any event.

Another question I wonder about it is something that looks like a regulator. It has three 1/8 inch connections (one top, one bottom and one side) and an adjuster of some kind teed on the same port as the top one. All are disconnected.

JimLL

 

[JimLL]

It seems I have heard about some kind of valve that unloads the compressor for easier starting. What would I call them if I looked for one?

 

[Kev442]

Unloader. Usually part of the pressure switch. Small diameter line ending in a tiny spring loaded valve. When the pressure switch kicks off, a meter lever pushes the unloader valve in and re leaves the cylinder pressure.

 

[JimLL]

Unloader. Usually part of the pressure switch. Small diameter line ending in a tiny spring loaded valve. When the pressure switch kicks off, a meter lever pushes the unloader valve in and re leaves the cylinder pressure.

I take it, then, I have to be sure there is a rather large check valve between the compressor and the tank?

JimLL

 

[Kev442]

Yep. That is usually on the end of the copper line stuck into the tank. I got my check valve from CH direct and my pressure switch w/unloader 125 psi off epay.