Connecting a 220V Pump to a 120V Timer: Use a Pump Start Relay

You cannot directly switch a 220V pump with a 120V timer. The timer's low-voltage output (24 VAC) can only control a pump start relay, which then switches the 220V pump circuit.

Correct Setup

1. Timer (120V plug-in) → 24 VAC output from MV/P (Master Valve/Pump) terminal.
2. Pump Start Relay (coil rated 24 VAC, contacts rated 220V/amp) → wired to timer's MV/P and Common.
3. Relay contacts → switch the 220V pump power legs (L1, L2).
4. Separate 220V supply feeds the pump through the relay contacts.

If Timer Is Mechanical (Indexing Type)

Some mechanical timers (e.g., Intermatic, Hydrotek) have line-voltage switching contacts rated for 1.5 HP. If yours does, you can wire the pump directly to the timer's load terminals — but verify nameplate ratings first.Electronic Timer? Must Use Relay

Electronic timers (Hunter, Rain Bird, Irritrol) only output 24 VAC — always require a pump start relay for 220V pumps.

Need Help Selecting?

Provide timer model and pump specs (HP, voltage, phase) for exact relay recommendation.