Toro Extra Timer & Hunter PSR-22 Relay: EMF Interference Myth

Pump Relay Inconsistent Activation: Real Causes vs. EMF Claims

Toro Extra timer with Hunter PSR-22 relay. Relay clicks but pump doesn't start consistently. Timer shows "Mv" error (excess current). Manual start often works. Components mounted within 6 feet. Vendor claims 15-foot separation needed for EMF.

EMF Claim Debunked

No credible evidence supports 15-foot EMF separation requirement. Professional installers routinely mount relays adjacent to controllers (inches apart) without issues. The PSR-22 is designed for close proximity.

Actual Root Causes

1. Timer output stage weakness: Toro Extra (aftermarket) may have marginal triac/relay drive capability
2. Relay coil inrush current: Exceeds timer's rated output, triggering "Mv" protection
3. Solution: Replace timer with commercial-grade (Rain Bird ESP-TM2, Hunter X-Core, Irritrol Rain Dial) or try lower-inrush relay

Pump Proximity

Timer near pump is fine if wiring is correct. The 15-foot pump separation claim is equally unfounded.