Noob to big boy compressors... seeking help

[toddjb]

Okay. After some research I found Type K Soft Copper sold by the foot from Plumbing supply. With that and a couple of fittings I ordered from them I'll have my discharge pipe made up for about $20 (It added up to $60 from the local big box with hard copper and fittings).

I'll work on setting up a 20amp service line on the wall, square away the electrical on the compressor while I await it's arrival, and I'll ponder how I want to install my air lines.

 

[icedoc]

Thanks Icedoc, this would require a full replacement of the pressure switch correct, like the example that Brendan gave above? There isn't an option to add an unloader to the PS?

Simple answer is yes. I'm sure if you got complicated with it you could rig up an electric unloader (solenoid type), but I don't see this being easier or cheaper than replacing the pressure switch.

It sounds like you are going the mag starter route, so you won't need that heavy duty pressure switch anyway. With the mag starter, the pressure switch current is minimal, unlike the switch you currently have, which is designed to handle the line current going to the motor. Your current switch can of course be used for lower current, if you decided to keep your pressure switch with the new mag starter.

If it were me, I would go new pressure switch with built-in unloader and add a mag starter. Tee in to your discharge line for the unloader and make sure you have a working pressure relief valve on the tank and in between compressor stages.

 

[toddjb]

Got it. Thanks, that's really helpful. I can be thick headed about stuff some times. My reluctance with replacing the pressure switch is that it's hard to believe they are of any quality for around $20. Ha. I have minimal faith in modern manufacturing. But I think you're right, I'll hook up one of my spare mag starters and replace the whole P.S. unit.

I have a relief valve on the tank and between the stages, so that's good to go, just need to order a pressure switch, tee, and line to adjoin them.

 

[motofool33]

Todd, i went through all of this with my T30 in this thread,

i ended up putting in a new check valve intank style, about 17$ northerntool carries them or i got mine off Ebay. the pressure switch i grabbed from northerntool just a standard switch with built in unloader i also have a 5hp motor with internal thermal protection. i did not use a mag starter for this setup, its working fine. I would use a mag starter with start/ stop and reset like the WEG ones that i just ordered for my new compressor. because i have no way to turn mine off except unplug it

i would be surprised if a 20amp breaker and service does not pop trying to run this compressor

http://www.garagejournal.com/forum/showthread.php?t=288765

 

[motofool33]

also if it was me i would order a pressure switch that has the ability to adjust cut in and out pressure. mine only adjusts cut out cant adjust cut in

 

[QuickRick]

Todd,

I have a I-R 5 hp comp that I have updated with a new pressure control, check valve, un-loader and 2 stage pump.

It is plumbed from the pump to tank with flared copper. It doesn't matter if you use a stock design only that you wire and plumb it right. My pressure control has worked without a magnetic starter for over 10 years without issues.

I have a similar pressure control, it is a Square D like yours. Mine has a built-in un-loader bleed port.

Provided you know what the motor amp draw is and your garage can support it (about 20 amps with my 5 hp-240 volt single phase motor) it will start and run perfectly. Mine automatically starts at 90 psi and stops at 125 psi.

I took photos of it all and have a wiring schematic as well. If I draw it all out including how I retrofitted my check valve, would you follow it? Let me know.

QR

p.s. I couldn't locate my I-R check valve to replace so I got a nice one off of Ebay. I like this check because it has a 1/4 inch port to locate your un-loader line. This line should drain the head pressure off but not the tank and this port facilitates that easily.

 

[MacMcMacmac]

That seems simple enough, Mac. So all I would need to do is mimic the example given (elbow in case -A , elbow in HP head - B, or somewhere below - C, and a tube connecting them)?

No, you would need the following parts inside the compressor to make it work:

Since you don't have that setup, you need to go with the pressure switch blowdown valve.

The flyweights mount to the end of the crank, and along with the spring, allow the pin 13 to move in and out as the pump starts and stops. The tiny o-ring on pin 13 seats when the flyweights move out and retracts the spring loaded piston. When the pump stops spinning, the spring over comes the flyweights, pushes the piston outwards and lifts the little o-ring off of its seat, allowing the high pressure air trapped between the pump and check valve to blow out of the line and into the crankcase. A lot of the better machines used a centrifugal unloader system like this.