Breaker keeps tripping when turning on pump.

check the breaker might be weak possibly from previous pump motor also if it was hooked up incorrectly at first might have done damage to motor windings

You are correct in assuming Hayward won't be of much help. A.O. Smith used to be original equipment on several brands of pool pump motors. Over the years Century/Magnatek took the business away from A.O. Smith, so A.O.Smith bought Century!
Most pool pumps have a 1081 designation on them. It has been a while but I think that means it is rated for continuous duty (24/7).
I'd call a local motor shop, they rebuild these things all day long.

How long has it been since you have the new motor installed? Did it work after the job was completed? Very possible that the starter circuit has failed, usually when it comes on and runs but overheats and stops, the starter and run circuits are both engaged and that causes it to overheat. If you can read the wiring diagram on the motor and make sure it it correctly wired, you may save it if it is a simple loose wire. Otherwise it sounds like you will have to have whoever changed it come back and do a warranty repair.

It you either have an impeller problem or capacitor problem on the motor. I would take the capacitor off and take it to a electronic or lexical shop to have them check it. It's only about 15 to 20 dollar pics if it's just your capacitor.

A thumbs up would be greatly appreciated if answer is helpful for your question. THANK you and GOD BLESS YOU.

VOLT METER TO THE 2 LINES 230 OR SO ? THE MOTOR MAY BE BAD.. SEARCH YOUR AREA FOR YOUR LOCAL POOL PUMP MOTOR REPAIR GUY..USE YOUR ZIP CODE ... GOOD LUCK AND VOTE FOR ME...JAY

try running up this motor when its not installed on the compressor,, if it still blows the trips the motor is faulty,, if it runs ok, but hums when reconted to the compressor the compressor if far to tight for the motor to turn the compressor,,,you can not reset the points in a breaker trip they trip at a set curent if the motor is pulling more amps than the trip is set for it will trip the trip to turn off the curent, the motor will pull far more amps than it should if its over loaded thats why its humming its trying to spin up it but cant so it just keeps pulling more and more amps till the trip cuts out

Sorry to say the motor is burnt out at this point and you will need a new one. Sorry.

A.O.Smith USQ1152.

If you did not press a reset ( and even if you did) the motor is damaged and that is causing the circuit breaker to trip. You need to have the motor inspected to see if the damage is repairable or if you need a new motor. A local electric motor repair shop should be able to take care of that for you. The thermal overload has reset itself if after cooling down the motor is trying to start but trips the breaker.

To be certain it is the motor, disconnect the line leads and be sure they are insulated from ground and one another. Turn the breaker back on. It should stay closed which confirms it is the motor tripping it when connected.

If for some reason the breaker still trips, there is a problem with the electrical circuit feeding the pump.