2. Control Functions
Control functions on the module
SMGB0097 rev.0 - 07/2015
16
2.1.5 Prevention of simultaneous startup
This function prevents simultaneous startup when supplying power to multiple units (in case that all modules are working
individually, not in a master-slave group)
In case that multiple chiller units are installed, it may be thought that all of them will start operation simultaneously when
3 minutes have passed after entering in recovery from power interruption. (Note: When using the function to control
the number of units, simultaneous startup is prevented by performing sequential startup automatically. ) To prevent this
phenomenon, it is possible to shift the settings of time guard (3 minutes).
Setting method
By means of DIP switch setting (DSW3-1#, 3-2# ,3-3#), the following number of seconds are added to the time guard (3
minutes).
DIP switches (DSW3-1#, 3-2#, 3-3#) are used for address setting when using the functions to control the number of
units, but the addition of time to the 3-minutes guard is effective even if these functions are not used. In this case, it is not
necessary to connect transmission cables between each chiller unit. )
Unit No.
DSW3 (PCB
A
)
Added
time
#1
#2
#3
#4
1
OFF
OFF
OFF
OFF
0 s
2
OFF
OFF
ON
OFF
5 s
3
OFF
ON
OFF
OFF
10 s
4
OFF
ON
ON
OFF
15 s
5
ON
OFF
OFF
OFF
20 s
6
ON
OFF
ON
OFF
25 s
7
ON
ON
OFF
OFF
30 s
8
ON
ON
ON
OFF
35 s
Example: When setting 2 chiller units as unit 1 and unit 2,
upon recovery from momentary power interruption unit 1
restarts after 3 minutes and unit 2 restarts after 3 minutes
and 5 seconds.
N O T E
Power reactivation needed
2.1.6 Reverse prevention control
The state of three-phase input is detected in this chiller unit, and it does not operate in case of reverse or open phase.
Three-phase input
detection
Reverse
phase
Open phase
Alarm display "Reverse/open phase"
(Open R phase)
(Open S phase)
(Open T phase)
Alarm display "Reverse/open phase"
