Sherman wrote:


The compressor(Item No. 90385-4VGA) works fine when plugged into a
115v outlet, but not when connected with an extension cord. Even a
heavy duty cord causes the push-button circuit breaker to blow when it
trys to restart after the pressure falls and the unit tries to kick
in. When you push the button, the unit tries to start but kicks the
breaker after about 1 second. Sometimes it just whines without
turning over before it kicks the breaker. With an extension cord, you
can only restart it by bleeding off the back pressure.

There are two capacitors, a start capacitor and a run capacitor.


The documentation states that the compressor warranty is void if you
connect it to an extension card. And of course, if you run it without
oil.
info:
Heavy duty 2.5 HP rated motor
Air delivery: 5.6 SCFM @ 90 PSI; 7.2 SCFM @ 40 PSI
Oil lubricated pump
Thermal overload protection
Dual capacitors for fast, easy starts
Easy-to-read pressure regulator gauge
Clear view oil window for easier maintenance
High impact ABS shroud protects the motor
CSA certified
120V, 60Hz, 3400 RPM; Single stage pump, 120 PSI max; Air outlet:
1/4''-18NPT; Weight: 65 lbs.

You think a hard start kit would help?






Sound like it doesn't have an "unloader valve" on the compressor to
relieve it of having to work against pressure in the tank when it's
trying to start. That's why it will restart when you drain it down to
zero gage pressure, but not when you are just down to the "start" pressure.

What do you mean by "heavy duty" extension cord? What gage wire does it
have in it? And how long is it? There is no theoretical reason why you
can't make an extension cord of even several hundred feet length that
would support the starting load. But there are practical reasons like
weight and flexibility. If your extension cord is made with less than
No. 12 gage wire, get a heavier one.

BTW, that 2.5 HP rating is a BS "peak horsepower" number, just before
the motor stalls out and burns up. You can't get a 2.5 HP motor to run
continuously off a "normal" 115 volt circuit.

You get what you pay for. A better and more expensive compressor will
have an unloader system to prevent just what you are experiencing.

Google up "unloader valve" and see what you can buy to add to your
compressor.

HTH,

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."