Choosing a magnetic starter

[slackdaddy1]

Just put a new WEG 5HP motor on my compressor, need to add a mag starter with overload protection.
The WEG motor is rated at 21.5A @ 230v

The Mag starters listed for 5HP are 22-32 amp,,
I found one listed for 3HP that is 18-26 Amp.

Which one?

Slack

 

[foghorn1966]

Easy, 5 HP motor = 5 HP starter. There is a reason they are rated in HP, mostly due to the inrush current of the motor.

 

[FTG-05]

Even though my compressor has a 5 hp motor, it has a 7.5 hp pump. Hence, I got a 7.5 hp rated Mag starter in case I ever want to upgrade the compressor. Not much more $$ over a 5 hp. I got a WEG version, I'll have to dig up the model # later whne I find my phone.

 

[TRWham]

Also look at the Square D 8911 starters on Amazon. I would get the larger one and tune it down to match the load. As long as the contactor is big enough, you can tune the overload setting or heaters to better match the actual load. Do not oversize the protector setting too much. A starter can prevent a motor burn-out by tripping if it is overloaded because of a mechanical issue like a seized pump or drive problem.