Hitachi SAMURAI Series Service Manual page 53

2 Control Functions
Control of Master/Slave group
¢ Setting temperature difference
Sets the target difference between water inlet and outlet temperature to increase the number of units in operation.
£ Temperature range of addition
Sets the range of change of inlet water temperature to add units, in case that the difference of temperature reaches
the temperature difference set at ¢.
 Temperature range of reduction
Sets the range of change of inlet temperature to reduce units, in case that the difference of temperature reached the
temperature difference set at ¢.
 Waiting time for effect of addition
Sets the time during which the next addition process is prohibited, after having added once (start-up of 1 unit).
Recommended > 3 minutes
 Waiting time for effect of reduction
Sets the time during which the next reduction process is prohibited, after having reduced once (stop of 1 unit).
Recommended > 3 minutes.
§ Number of Units at Startup
Sets the number of modules to be started up upon system start-up.
 Maximum number of operating units
Sets the upper limit of the number of modules that can be operated at the same time.
© Minimum number of operating units
Sets the minimum number of modules to be operated at light load operation.
 Pump operation
Selects batch or individual.
When selecting individual, pump operation order is linked to the run/stop of the module.
When selecting batch, all the modules which are target of the control of group (Master/Slave) during system operation
set pump operation order to ON continuously.
 Priority setting
It is possible to set a priority order, when it is necessary to operate a certain unit preferentially.
It is possible to set up to 8 steps for priority order.
In case that there are multiple modules with the same priority order, they operate in rotation.
?
N O T E
• The operation time of units with higher priority order becomes longer.
• Settings ¢ to  are performed at the Number of units setting screen. Refer to "2.3.6 Method for setting and confirmation of operation
conditions through the LCD screen".
45 SMGB0120 rev.0 - 11/2017
Number of the
1 2 3 4
module
Priority setting 1 1 1 2
In case that there is a load
This 3 units are
exceeding the amount of 3
operated with the
units, one unit out of these 4
maximum priority, with
is chosen for startup, with a
a rotation based on
rotation based on operation
operation time
5 6 7 8
2 2 2 3
This unit is
the last one
to start up
time.
2