Taco PC605, Priority Protection Plug-In Card

Taco PC605 Priority Protection Plug-In Card is a solid state control that helps prevent freeze-ups in the event of a priority zone failure. If the priority zone calls for heat continuously for more then one hour, power is returned to the space heating (non-priority) zones, allowing all zones to function independently. Once the priority zone is satisfied, the PC605’s auto-reset is activated and the priority zone is again allowed to have priority for up to one hour the next time it calls. The one hour time frame is not adjustable. The red LED light is energized only when the Priority Protection Card is operating in priority override mode.

Documents:

Taco PC605-1 Instruction Sheet (pdf)

Taco Wiring Guide (pdf)