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- Jul 29, 2014
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A friend GAVE me an Ingersoll Rand T30 air compressor, so I installed it outside of the shop, with a local disconnect box and another box for the magnetic starter. There is a small leak that causes it to cycle once a day or so, and one day I'll take the time to track this down...but for now I've been shutting it off when I'm not in the shop, or on the phone, or just not in the mood. This involves going outside, ducking under a shed roof, and reaching back (in the dark ) to throw the disconnect switch, then reverse steps the next day to turn it on.
So I built a very simple remote control system to allow me to turn the compressor either "OFF", or to "RUN", where like normal, it will manage itself based on air pressure. With winter and hopefully some rains coming, this seems like a good idea.
To do that, I just added a low voltage relay to interrupt the pressure switch input to the mag starter. The pressure switch is a normally closed switch that opens when the pressure reaches the upper limit. If the pressure switch line is open, the compressor thinks it's full and will stay off until you remotely switch the low voltage coil back to "RUN", whence it operates normally. I set it up so the un-energized state of the relay opens the pressure switch line (STOP). stopping the compressor, and the energized state (RUN) actively connects. It's low voltage of course so I can run long wires to the switch without hazard.
There is a 220VAC to 12VDC power supply, a relay with a 12VDC coil and contacts that are rated at 250VAC at 10 amps. What makes this interesting is the low cost of all the parts. The power supply is, get this, $3.85 post paid from China, the relay is about the same, but the DIN relay socket is also about that much, and the OFF/RUN switch is about the same. So maybe $16 for parts.
The pressure switch lines are brought out of the mag starter box to the main disconnect box, where the power supply, relay and socket are located. The remote switch controls the relay coil current.
Here are some shots of the components. If anybody is interested, I can show a simple wiring diagram of this.
So I built a very simple remote control system to allow me to turn the compressor either "OFF", or to "RUN", where like normal, it will manage itself based on air pressure. With winter and hopefully some rains coming, this seems like a good idea.
To do that, I just added a low voltage relay to interrupt the pressure switch input to the mag starter. The pressure switch is a normally closed switch that opens when the pressure reaches the upper limit. If the pressure switch line is open, the compressor thinks it's full and will stay off until you remotely switch the low voltage coil back to "RUN", whence it operates normally. I set it up so the un-energized state of the relay opens the pressure switch line (STOP). stopping the compressor, and the energized state (RUN) actively connects. It's low voltage of course so I can run long wires to the switch without hazard.
There is a 220VAC to 12VDC power supply, a relay with a 12VDC coil and contacts that are rated at 250VAC at 10 amps. What makes this interesting is the low cost of all the parts. The power supply is, get this, $3.85 post paid from China, the relay is about the same, but the DIN relay socket is also about that much, and the OFF/RUN switch is about the same. So maybe $16 for parts.
The pressure switch lines are brought out of the mag starter box to the main disconnect box, where the power supply, relay and socket are located. The remote switch controls the relay coil current.
Here are some shots of the components. If anybody is interested, I can show a simple wiring diagram of this.