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Adding Manual Pump Switch to Hunter Controller Without Feedback Damage

A homeowner wants to add a manual switch at the controller to operate the pump start relay independently of the irrigation schedule, using a Hunter controller and pump relay.

Electrical Considerations

The controller's pump/MV terminal only outputs 24VAC when a zone is active. Tapping this directly won't work for standalone pump operation.

Correct Implementation

Use a separate 24VAC transformer (not the controller's)
Wire a switch between this transformer and the pump start relay coil
This isolates the manual circuit from controller electronics

Why Not Tap Controller Transformer?

Controller transformer sized for controller + valves only
Risk of backfeeding voltage into controller circuits
Code violation in many jurisdictions

Have an electrician install a dedicated 24VAC transformer (40VA+) with a weatherproof switch. This provides reliable manual pump operation without risking controller damage.

Irrigation: Rain Bird Controller On But Pump Not Starting: Test PS/MV Terminal Voltage; Troubleshooting Sprinkler System Error Codes After Plumbing Work; Rain Bird Controller: New Unit Doesn’t Start Pump – Wiring or Pump Issue; Pump Relay Not Clicking? Check Voltage at Relay & Controller; KwikDial Controller: All Zones Show Voltage Simultaneously—Controller Failed; Rain Bird 9-Zone with Richdel Valves: Only Zone 6 Runs After Heavy Rain; Rain Bird System Requires Manual Pump Switch – Relay or Wiring Fault; Toro Controller Blows Fuse Intermittently – Locate Valves with Wire Tracer; All Zones Run Simultaneously: Controller or Valve Issue?; Well-Fed Sprinkler System: Some Zones Work, Pump Loud

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