Mitsubishi Electric PWFY-P-NMU-E-AU Engineering Manual page 36

11. SYSTEM DESIGN
11-3-5. Pump Interlock
The unit may become damaged if it is operated with no water circulating through the pipes.
Be sure to interlock unit operation and the water-circuit pump. Use the terminal blocks for interlocking TB142A (IN1)
that can be found on the unit.
TB142A
IN1
PWFY-36 PWFY-P-NMU-E-BU/PWFY-P-NMU-E-AU (Sept. 2010)
Control Box
Operation signal
Pump interlock
Strainer
Water Pump
Pump Interlock Example Diagram
Broken lines are field
supply products.