I am running a 7500 Watt Onan Diesel generator, and a regular belt driven Puma compressor (smallish) with an induction motor (whatever that means). I have read that running a compressor on a generator can burn out the compressor motor.
The generator is from an RV and used to run 2 air conditioners at the same time, so I figured I was OK. You can hear the diesel rev up when the compressor kicks in, but it doesn’t seem to struggle starting it.
Am I OK here, or will I hurt the compressor?
BTW – thanks to BTers for the “pig” idea: my old compressor is now air storage – I can put up half a square of shingles before the compressor cycles – love it!
Replies
I did that for years Brian.
blue
Thanks for the reply - I really don't have another option fro a few months, so I'll be doing the same.
If the generator doesn't falter when the compressor kicks in and the compressor starts and runs smoothly, without struggling, your likely alright.
Generally in such arrangements the weak point is the extension cords and cord caps used. Use a high quality heavy gauge, #12 at least, extension cord that is as short as practical to keep the voltage drop and line losses to a minimum. Far better to run a longer air hose than a longer electrical cord. If you have a choice get one with robust and corrosion resistant prongs on the cord caps. Keep these connections clean and tight.
A general rule of thumb is to let the load run as continuously as possible for a time and to feel the cord and caps. An overloaded or stressed cord will be more than slightly warm. Similarly a cord cap going bad under load will tend to heat up under load.
Other than these few points, I assume mostly covered already, your likely doing OK.
On another thread a cord overheated and caught fire when the cord feeding the compressor was accidentally disconnected and then too quickly reconnected. The unloading valve on the compressor hadn't had time to drop the pressure in the pump cylinder so when the cord was reconnected the motor driving the pump had to start, a demanding task in itself, against the back pressure. This cause a very large current draw that damaged the cord caps and could have damaged the motor and cord itself.
To prevent this, and possible damage to the generator, if the compressor is disconnected let it stand idle for a minute or so. Don't be too quick to reconnect the power. This delay will allow time for the compressors unloading valve to function fully. Preventing this 'hard start' issue and saving wear and tear on the compressor motor, generator and cord.