Compressor Question

[Jim Guy]

My shop is inside my barn, my compressor is outside the shop but still inside the barn. (Keeping the noise down) Whenever the temp drops below 30 degrees and the compressor kicks on, it kicks a breaker. Before it does I can hear the compressor really laboring. My question is, should I be changing the oil in the compressor during the winter, or is this normal? We're in a really cold spell here is southern Ohio and I could have no air for several days.
Thanks,
Jim Guy

[Dave Bartley]

My reccomendation would be to wrap the compressor body with heat tape. In the long run it would be far less hassle.

You may also want to check the wire size and at the same time, check what amp load it is drawing when it kicks the breaker. Just for safety sake.

[Rob Russell]

Jim,

You've got an interesting problem. Changing oil to a multigrade or lower weight might sound good, but I'd check with the compressor manufacturer first. You also need to be careful about what type of oil you use (deterent vs. non-detergent). For example, a synthtic oil might sound like a good idea (Mobil 0-30 or 5-40, for example), but the manufacturer might say "No way" because of some reason we just aren't aware of. It's not really surprising that the startup load is popping your breaker. FYI, for a high-startup load like that, you could easily run a breaker that's 200% of the rated FLA of the motor. You'd need a separate overload sized to the FLA rating of the motor.

As a totally different aproach, move the compressor inside the barn and box it in to muffle the noise. Compressors don't need a huge amount of airflow to work and it would, long term, reduce the wear on your compressor's rings, etc. if the ambient temperature the compressor is running in is more moderate.

Rob

[Ken Garlock]

Hi Jim, I guess it is not running today with the temp down around zero in Ohio.

I when I took delivery on my Ingersoll Rand 5 hp compressor, it came with 100% synthetic oil. Thus I would recommend getting some good synthetic 5W30 for it.

Another thing to check is to make sure the motor is getting out of the starting winding, or never getting back into starting winding when it shuts down. Dirt and grime in and around the centrifugal switch may be gumming up in cold weather. Just a guess ....

[Greg Mann]

Most compressors have a no-load start-up function. This is so that the motor can gain some inertia to counteract the latent pressure that would stall it on start-up. This is why we hear, or should hear, a blast of air being released as the motor shuts down after recharging the tank. It is basically unloading the compressor, but not the tank of course, so that it will have a pressure free start. Maybe a dump valve is not liking the cold. If you don't hear it dump air at shut-off, once you get it to cycle, that is a good place to start your investigation. I would suspect there is someplace to manually bleed off the compressor itself so that you can check this out.

On a related note, if your intake air is really cold, you are setting yourself up for a lot of condensation, and possibly frost, in these critical areas. If the compressor does not get warm enough to combat this, you can have problems.

Greg

[Tyler Howell]

Hey Jim,

Along the same lines, I attach a magnetic block heater to the compressor when used this time of year. Give it about 1/2 hour lead time and she works great.
Special consideration for draining the tank before the freezing temps.

[Jim Guy]

Thanks everyone for your input. I have given some thought to building a insulated plywood box, open just a little at one end and placing a light bulb inside that for heat. Don't really know if that would work.
Tyler - any more information on the magnetic block heater? Not certain what that is.