Tag-Teaming Your Air Compressors

Woodworkers discuss various ways to tie two air compressors together to operate in tandem. January 27, 2008

What are the considerations regarding a tandem hook-up of air compressors? I have two 60 gallon compressors that I'd like to connect to the same air system. Is there any reason this shouldn't be done?

Forum Responses
(Dust Collection and Safety Equipment)
From contributor C:
I have two 80 gallon compressors hooked up at my shop. I have the pressure switch for one set at 100psi and the other set at 120psi. Both usually do not run at the same time until they go below 100psi and this is not often. The main lines coming from the tanks are hooked to a T and the line coming into the shop is coming off the other leg of the T. I have had this set up running for several years.

From contributor S:
We have two individual units that are wired in. A third unit is tied into air lines but only used as a volume storage tank. We alternate every other day between the two units. If we have serious usage we can turn both on at the same time. The third is nothing more than a holding tank but is available for use should one of the other two die. No special valves or setups are necessary to gang them.

From contributor L:
If you need the volume, I would wire the relay for #2 to the pressure switch on #1 and have them both run/stop at the same time. You'll build pressure twice as fast, so they'll run half as long.

From contributor K:
We also have two compressors set up, one at each end of the shop. The air lines run from each compressor up to the center of the shop and we installed a simple gate valve that we leave closed. The few times we have had a problem with one compressor, we open the valve and can get by for a while running the whole shop on one unit while we do maintenance or repairs on the other. Both units are set to come on at 90 lbs and shut down at 150 lbs. By having the valve between the two, there is no drain off from one unit to the other.

From contributor H:
Contributor L, I would not run #2 compressor off #1's pressure switch. For safety have each pump triggered by a pressure switch on its own tank. If they do not come on at exactly the same time, you save on peak demand rates from the power company.