3.5 hp Speedaire bogging till overload on motor trips

by Tony
(Ardmore Ok)

60 gal. 3.5 hp Speedaire. bought it used a few years ago as a backup. now I need it and it wont run. Runs great for about 30 sec. then bogs till it eventually trips overload on the motor. Have replace motor, pump, and tank check valve. messed with pressure settings and doesn't change anything. I'm at a loss completely. Tried bypassing pressure switch and does the same thing. Gets up to about 20 psi and starts bogging. Please Help!!!!

Comments for 3.5 hp Speedaire bogging till overload on motor trips

Click here to add your own comments

Oct 15, 2016
i connected it to 220 volts, it worked fine
by: Anonymous

i had same problem, and solved it by connecting to 220, not-110, and it worked fine

Feb 09, 2016
air compressor motor bogging
by: Mike LaFavor

if your motor is not a totally enclosed mud dobbers can build nests in your motor.

this restricts air flow, building heat causing the thermal overload to trip.

they can also dirty up the points for the start capacitor.

it may be worth a look to see if this may be an issue. I have this happen to me when periodically.

Jul 15, 2015
by: Doug in s.d.ca

Got it.

Have you checked the power?

Jul 15, 2015
Everything is NEW
by: Tony

so last night I replace the power cord and the pressure switch and had zero improvement to the situation!

so here is where I stand.

initial problem has happened since before replacing anything and has not improved with any of the parts replaced.

I have replaced the motor w(marathon #GEX09040), the pump w(campbell hausfeld vt0407), power cord 8ft long 12 awg 300volt, Condor pressure switch MDR11 125-155 psi, and new check valve and pressure gauge.

So now all parts are new, and the issue HAS NOT improved in the slightest.

so starts up great, runs till around 20 psi and then starts bogging till it trips the overload on the motor.

The breaker has never tripped, only the overload on the motor. What gives???

Jul 14, 2015
by: Doug in s.d.ca

Check the voltage at or near the compressor motor.

Whatever it is when the motor is off should be no more than 105% of the voltage with the motor on (or trying to run). E.g., 120V off and not less than 114V with motor on.

You may need to run bigger wire or get rid of any extension cords and other stuff on the same circuit.

Jul 14, 2015
response to response
by: Tony


It did this with the old motor as well as the new one I installed. I have replaced the motor, pump, and check valve and had no improvement.

Jul 14, 2015
3.5 hp Speedaire
by: Bill

Tony, it's power related, I suspect.

My guess is that the start or run capacitor is failing.

See the page on this site about how to check your caps.

Add a comment if, after checking them, the problem persists.


Click here to add your own comments

Add your own question or comment. It's easy to do. How? Simply click here to return to Speedaire Compressor Issues.