External Thermo Operation From External Contact - Hitachi SAMURAI Series Service Manual

2 Control Functions
Control functions on the module

2.1.11 External thermo operation from external contact

In case of setting the chiller unit to run/stop with the order of an external contact such as that of a (locally supplied)
external thermo, capacity control function is disabled and operation is performed at 100% load. This function is mainly
oriented to thermal storage operation.
It is not possible to use this function together with the function to control the number of units.

Setting method
1 Set the local/remote switch (SW2 on PCBa) to remote side.
2 Connect the forced load operation switch to [24]-[25] of terminal block.
3 The wiring side used together by normal remote operation (air conditioning operation) and forced load operation
(thermal storage operation) is shown.
Local
Switch
SW2
PBSR2
(OFF)

Time chart
Forced load
operation
switch
?
N O T E
• Forced load run/stop from local external contact cannot be performed by pulse signal.
• Normal operation order and thermal storage order must be input to the chiller unit separately.
• For local external contact orders, ensure a minimum interval of 5 minutes of continuous operation order (5 minutes of stop time, too).
• For the additional wiring, put it separately inside a metallic pipe, or use a shielded wire.
• Always operate the air conditioning/thermal storage switch while the chiller unit is stopped.
23 SMGB0120 rev.0 - 11/2017
Remove the wiring between
5 and 6 if it is connected
5 6 7
Air conditioning
(Thermal storage)
Switch between air conditioning
PBSR1
(OFF)
2 0V 3
ON
OFF
Keep more than
Run
Chiller
unit
Stop
(Air conditioning)
and thermal storage
Keep more than
5 minutes
5 minutes
24 25
(Thermal
storage)
SW2
Forced
load
operation
switch
2 0V 3
2