The style of the compressor is not important.
What is important is the horsepower of the motor and if the compressor has an automatic unloader. (Paul, a pancake type is a "flat" tank rather than a cylinder, side view looks like a tire.)
As Paul said the cap is for "kick" starting the motor, not for reduced current. The unloader is probably the most important component to reduce tripping on start up anyway.
I own a 4 gallon unit and have no problem running it on 15A 120VAC circuits.
