Mitsubishi Electric PWFY-P100VM-E-BU Data Book page 63

(10) 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. In the system including PWFY-P100VM-E-BU, use the
terminal blocks for interlocking TB142A (IN1) that can be found on the unit.
[Fig. IV. 3. (10).1]
In the system including PWFY-EP100VM-E1/E2-AU, the circulating water may freeze, and result in a unit malfunction.
Perform the electrical work as shown in [Fig. IV. 3. (10).2] to prevent water from freezing.
Set the DipSW as shown in the table below.
DipSW3-6 External output contact
ON Effective when Thermo-ON
OFF Effective when Operation-ON
(Remote controller-ON)
Be sure to turn on the power supply of the pump, since
the control does not work if the power supply of the pump
is turnd off.
*Refer to (7) Flow switch installation for details.
F: Fuze
52P: Magnetic contactor for heat source water pump
MCB: Circuit breaker
WP: Water pump
Operation signal
Strainer
Example drawing for pump interlock
[Fig. IV. 3. (10).2]
- 55 -
Control Box
Pump interlock
Broken lines are field
supply products.
Water Pump
Board
AC220V ~ 240V
TB141A OUT1
DC30V or less
52P
F
or
L N
MCB
52P
WP