Wiring short at my pump/pump controller... Help Please...

motaskate

Member
Aug 15, 2019
6
Ventura County
Any assistance would greatly be appreciated.

I was running my 3-phase hayward pump and heard a loud pop and suddenly the jets stopped. Sure enough the breaker was tripped, so I pulled out my voltmeter and traced the short back to the Hayward tristar variable speed pump controller.
In the picture you can see the two 120V hots with yellow covers. I disconnected them from the controller's terminals (the gray box on the right of the picture). When i test the two terminals on the controller they have continuity between them. I'm thinking there's the short inside the fried controller. However, my question though is that when I test the three lines (Black, Red, & blue (from left to right)) for the output voltage to the pump itself, there is also continuity between all three of these wires. Is this normal for a 3 phase pump? Do all these wires connect on the same winding terminal on the pump end, or is there likely a short that needs to be investigated at the pump's input terminals as well?

Please note that the input port is the one on the left at the bottom of the picture with the 2 black hot wires. The port to the right is the output to the pump where the black, red and blue wires connect to the pump itself. I have also included the manufacturer's wiring diagram.

Josh

Pumo.jpg
 

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motaskate

Member
Aug 15, 2019
6
Ventura County
From what I can tell for a 3-phase motor, regardless of the star or delta configuration of the windings, the three phase wires should have continuity between all of them as well as equal resistance. Can someone confirm?

Also, to replace the pump controller I like $500+... thoughts on just replacing the entire pump with an "on board" control interface?
 

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Bama Rambler

Mod Squad
TFP Expert
Bronze Supporter
LifeTime Supporter
Jun 22, 2009
23,638
SouthWest Alabama
You are correct that there will be continuity between all the phase legs of the pump, and the resistance should be essentially equal.

It's hard to test resistance on the drive because there are components on the drive that will read almost zero resistance with a meter.

If your pump is several years old I'd look for a complete new unit. You're likely to find a complete unit for little more than the cost of just the controller. If you decide to replace just the controller you should do some extensive testing to ensure that the pump motor isn't also bad.