Problem with 230 volt double pole single throw switch

rdempsey

I want to install a DPST switch between a disconnect box and a well pump. I installed the switch and when the switch is in the"ON" position, the pump works fine. When I turn the switch to the "OFF" position, the relay in the disconnect box chatters (very rapid on-off) until I dosconnect the power. Any ideas sas to why the chatter?

gregzoll

Post a schematic of how the switch is wired from the panel to the switch, to the relay, to the pump. If it is chattering, that means it is still getting voltage through current leak. What is the rating on the switch & relay?

AllanJ

Probably has something to do with the way the pressure switch is wired or whether its connections were disturbed when you installed the new double pole switch. I cannot speculate on it without seeing how the pressure switch and the relay are wired. Posting a picture of the wiring diagram (if there is one and it is still correct) can help.

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a7ecorsair

Yes, you have it wired wrong
Is this a 240 volt pump? Why not interrupt the power before the pressure switch?

micromind

With most pumps, there cannot be any switch between the control box and the pump motor. If these lines are switched off, the start relay and that start capacitor will form an inductive-reactive circuit. Basically, they'll fight with each other. This is the chatter you're hearing.

The switch can be installed anywhere in the line from the panel to the control box, and it'll work fine.

Rob

Missouri Bound

We have a similar situation with a waterfall pump at my work. When it is powered down, the relay chatters. In our situation it is the pump running backwards when it is shut off as the water "backflushes". When the water is gone, the chatter stops. By design we do not use a check valve as this "backflushing" clears any debris around the pump.

rdempsey

Rob, your answer fixed my problem. Thanks for the quick response - Rich