Have 2hp northstar pump and its humming and flipping the breaker and then stops. How do we get the pump apart to see if we need to replace motor or propellor?

Your heater will not work until you fix your pump, and your pump won't work until you replace the shorted out motor.

WARNING when replacing a motor on a northstar you must match the hp and service factor.. say its a 1.1/2 hp motor and the service factor 1.47 you will need a 2hp with a 1.15 service factor to replace that original motor .if you replace it with a 1 1/5 motor it WILL BURN UP THE MOTOR !!. welcome to the hayward northstar .
only the 2 speed motors have a start switch the CAPACITOR would be my first check it may be a 30 or a 35uf at 370 cap LOOK IN YOUR AREA FOR YOUR LOCAL POOL PUMP MOTOR REPAIR GUY WITH FREE TESTING USE YOUR ZIP CODE IN YOUR SEARCH

SOUND LIKE YOUR MOTOR IS TOAST ! DO TO THE COST OF MOTORS FOR THESE , REPLACE THE COMPLETE PUMP WITH A 1.5 HP STA-RITE DURA GLASS ! OR YOU MIGHT NEED A 2HP.. LOOK ON YOUR MOTOR LABEL FOR THE HP AND THE SF . TAKE A PICTURE OF IT AND PRINT IT OUT. BRING THIS INFO TO YOUR LOCAL POOL PUMP REPAIR GUY AND ASK WHATS THE BEST PUMP. THE ONE HE WOULD USE ON HIS POOL.. ANSWER ..STA-RITE.. WELCOME TO THE HAYWARD NORTHSTAR .. REMEMBER TO VOTE OR COMMENT .. IT IS THE FUEL TO KEEP ME TRYING TO HELP U GUYS .. JAY

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It could be the pump is bound up but it is more likely the motor is failing. It may be a small part such as the capacitor or the starting switch, but could also be more severe such as the winding itself. You will also want to examine the shaft where it passes thru the pump and motor and look for signs of rust from a pump seal leak.

If you are not familiar with testing these parts your best bet would be a local electric motor repair shop to see if the motor can be repaired or if it would need to be replaced. They should also be able to ensure there is no pump damage. Otherwise please reply with specific questions about what you find for more direction.

If this answer does not fix your problem, please comment with additional details prior to rating the answer. Positive feedback is appreciated once your problem is solved!

John

Something is binding in the pump try the impeller to see if it runs true when you have it apart. It may be cross threaded on the shaft. This is a common problem if you have a air leak in your system.

If the motor still runs at all start the pump with the lock off and it will pop out. If not use some liquid soap and a small straw like a capalery tube on wd. Any thing small enough to fit through the space you can get when you pull the seal plate back, their is an inner plate with an "O" ring and you need to get the soap to that then let it sit for half hour or so and go back to the side to side prying when the soap and the "O" ring come together it will slide right out.

capacitor maybe hard to tell must be check but the cheaper option will the capacitor check for loose wires

I'm guessing that you replaced the motor that goes to the pump, not the pump itself. You know the motor works just fine. Is the motor rotating in the correct manner(clockwise or counterclockwise) in relation to the rotation of the pump? Have you checked the pump to see if the impeller is working/rotating? Is the motor hooked up to the pump correctly, so that the motor is turning the impeller? Are all connections to the pump tight, so there are no suction leaks? Have you primed the pump and purged it of any air locks?

It has an internal thermal overload protection device that is turning it off. Once it cools enough it will automatically turn back on as long as whatever switch or timer you have controlling the pump is in the on position. If you are certain it is not due to a voltage or load condition then it would seem the only other problem is mechanical.

In any case try a local electric motor repair shop.