A new motor makes a humming sound without running.

[JamesW]

Watch to see if the contacts open.

There will be a tiny spark as the contacts open.

You might need to dim the lights to see the spark.

 

[skbr2019]

Can you post a video of the wiring compartment as the pump tries to start?

Because I don’t see any electrical problem, I thought it might be any physical problems.
I ran the motor after detaching the impeller. Interestingly, the motor can run well and the breaker does not trip.
Found out what the problem was…
The rubber ring from the old seal assembly was stuck on the impeller. I put a new seal assembly on the old one; I removed only metal part of old one. Because two rubber rings made extra space, the motor was stuck.
Anyway, I have learned a lot from you. Thank you so much for your help.
Have a nice summer!

 

[JamesW]

The shaft can move manually, no blockage in the impeller.

Because two rubber rings made extra space, the motor was stuck.

Ok, you originally said that the motor turned easily.

In any case, I am glad that you got it figured out and fixed.

Thanks for the follow-up report with the resolution to the case.