Delay Timer for Pump Pressure Switch on Canal-Fed System

Preventing Low-Pressure Cutoff During Pump Startup

A 1.5 HP pump drawing from a canal needs 5–10 seconds to pressurize the system. The pressure switch shuts the pump off because pressure is initially zero.

Off-Delay Timer Solution

An off-delay timer (up to 3 minutes) can bypass the pressure switch during startup. The pump will not be harmed by running briefly against a closed system.

Wiring Details

Wiring depends on whether the pump is 120V or 240V and where the pump control relay is located. A schematic can be provided via email (mwelch@chartermi.net) with those details.