Two Controllers, One Master Valve – Wiring Without Relay

Two old Rain Bird RC1260 controllers, side by side, need to share one new 200 PGA master valve. Controllers run at different times.

Solution

No relay needed if transformers are in-phase. Ensure:

• Black, white, green wires from each transformer connect identically to panel.
• Verify with meter: when one controller energizes MV, other shows 0V.
• Can also swap MV wire after transformer.

In-phase transformers allow direct parallel connection to MV.