Compressors Mantenance

[Mikeyeats]

Any pointers are appreciated. My old mechanic is no longer with us he use to say "mike you can pay me now or pay me much more later" I usually drained the tank every 6 months very rarely changed oil or did any real maintenance.
I am installing an old Webster 80 gallon tank 5 HP 3phase in a new location. It used for air nail guns every thing is 3/4" hard plumbed. The pressure regulator was functioning ( 80lb - 125lb max) prior to my move and I would like to move the pressure up to 150lb max. The electrician may have goofed up or not really understand the protection relay I had installed after The motor burnt out due to running on 2 phases overnight. I seems to start when I press the start button and will shut down at 125lb. but will not restart when it hit the 80 lb. minimum seems like the pressure relay has 4 terminals and only two wires go to the Protection box? I will have to call the electrician back more $$$

 

[Den N Ms]

Mikeyeats,It sounds like the cylinder head pressure relief (unloader) is not working.If it was working it should start at even 125.lbs.Then you could set the cutin to 80 lbs - 125 lbs and cutout pressure to 150 lbs.That is if it has a tank rating is for 150 lbs or more and a pop off valve of 155-160 lbs.Some pop off valves are adjustable so the pop off pressure could be adjusted to a higher pressure. Change oil monthly (if it is regular compressor use #30wt non detergent motor oil,weekly and check or replace air filter, monthly to.Drain the tank weekly and check belts when you check the oil.

 

[GarryinNC]

Two wires from the pressure switch are all that is required for the magnetic starter. It just completes the circuit for the magnetic coil to pull in. All of the motor amperage goes through the contacts of the magnetic starter. Motor protection is built in the starter box also.

Garry

 

[Steve@Advance]

Sounds like the electrician didn't wire it properly.

The starter he used is wired for a start/stop station. The push button needs to be replaced with a toggle switch, something that remains closed until it's time to shut down the compressor. The pressure switch is then wired in series with the toggle switch.

You need to look at the overload heaters, be sure they are matched to the full load amps of the motor at the voltage you are running. Some overload relays don't have replaceable heaters, but an adjustment dial to set the FLA trip point. Be sure that is also wired in series with the control switch to protect the motor.

If you raise the pressure to 150, be sure to check the motor amps. That may be too much for the motor to handle. A smaller motor pulley may be needed.

As for maintenance, now would be a good time to check all the unload components (if equipped), pull the valves, inspect the plates, discs, springs, housings, and decarbon them. Check the belts. Replace the air filter element. Change the oil, use synthetic reciprocating compressor oil. Synthetic works very well in old recip compressors as for preventing carbon in the valves. You don't want to use detergent oil, it will carbon worse.

 

[hd6gtom]

Sounds like you need a new pressure switch, you can get them from NAPA or any plumbing repair shop. There are different switches for different air cut out pressures. Probably put a couple of dozen on the first few years we had the tire shop, then we found commercial duty switches and I can't remember replacing 1 after we started using them.

 

[Mikeyeats]

(quoted from post at 19:34:54 05/02/17) Mikeyeats,It sounds like the cylinder head pressure relief (unloader) is not working.If it was working it should start at even 125.lbs.Then you could set the cutin to 80 lbs - 125 lbs and cutout pressure to 150 lbs.That is if it has a tank rating is for 150 lbs or more and a pop off valve of 155-160 lbs.Some pop off valves are adjustable so the pop off pressure could be adjusted to a higher pressure. Change oil monthly (if it is regular compressor use #30wt non detergent motor oil,weekly and check or replace air filter, monthly to.Drain the tank weekly and check belts when you check the oil.

You Guys are very knowledge able I will definitely get on top of this.
Thank you!
Mike