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by Geoff Wymer
I have 2 Kobalt 17 Gallon model 236005 compressors. Both have the same issue.
When you turn on the switch the motor will make 1 or 2 struggle revolutions and then it triggers a switch that kills the power. A few seconds later it resets and repeats. This is even with the tank empty.
When I took the line to the tank loose, it would fire and run, I could even reconnect the line and fill the tank once, but when the pressure went down and tried to restart- the same problem over again.
I bypassed the external regulator switch and that did not fix the issue.
Not sure what parts to get to fix this. Any help would be greatly appreciated.
When an electric compressor motor starts, it usually pulls more current than the electrical circuit can supply. To handle this “inrush” issue, your compressor motor has a start capacitor that adds power to the circuit, allowing the motor to kick over and start, without popping an internal or external breaker.
When a compressor is starting against pressure in the tank, then this inrush assistance is even more critical to the start, as the motor will draw even more than when the tank is empty.
It’s odd that you have the same problem on two compressors, yet, if they are the same vintage, perhaps not so odd.
This is what I think your compressor problem is, based on the details you provided.
If the power supply to your compressors is compromised (more appliances drawing power at the same time as the compressor) take other appliances offline while testing the compressor. The same for an extension cord, if you are using one. Both can cause compressor start and run problems.
Continuation/explanation of the problem
Thanks for the lesson. Some more facts to the story.
I was an employee for Lowe’s and bought both compressors after 2 customers returned them new with the issue described. It is too costly to have external company repairs done on the units due to labor costs, so we discount and sell.
That is why 2 with the same issue. Initially, I thought they had different issues and I could make 1 good out of 2.
They are both new but with the same issue. They were tried at the customer’s house, Lowe’s, and here at home with and without extension cords and different breaker strengths.
I was wondering if it could be either the check valve or one of the capacitors on the motor? My understanding of what those do is limited.
I was very excited to find your website and to read through all your postings. It has been very educational.
My money is still on the capacitors being an issue. How to check them is described on this page.
You are most welcome, Geoff.
These compressors have a thermal switch which means when it’s heating up it shuts off and in the case of Kobalt compressors even when it’s warm it will shut off. This switch is actually mounted on the motor itself so other than changing the motor there is no fix.