- 65 -
(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]
IN1
TB142A
Water Pump
Strainer
Control Box
Broken lines are field
supply products.
Operation signal
Pump interlock
Example drawing for pump interlock
In the system including PWFY-P100/P200VM-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
[Fig. IV. 3. (10).2]
Board
F
N
L
52P
MCB
WP
TB141A OUT1
AC220V ~ 240V
DC30V or less
or
52P
