Chapter4
Electrical Installation 23
Liebert. PEX+Series Precision Air Conditioner User Manual
55
55
51
51
50
50
24
24
38
38
37
37
76
76
75
75
56
56
71A
71A
70A
70A
71
71
70
70
78
78
77
77
To general
alarm
37/38 shorted,
removed
upon remote
shutdown
Customized
alarm terminal,
24 is the
common
terminal
RS485 port
Figure 4-3 Enlarged view of terminal block
warning
！
The connection personnel must take anti-static measures before connecting the control cables.
Connecting water-under-floor sensor
Each unit is equipped with a water-under-floor sensor. You should connect one end of the sensor to terminal 51#, and
the other end to the common terminal 24#.
The number of the sensors in parallel connection is not limited, but each unit has only one water-under-floor alarm.
Remote shutdown
As shown in Figure 4-3, 37# and 38# terminals can connect to remote shutdown switch, and they have been shorted in
factory and the shorting cable should be removed if the terminals are to be connected to the remote shutdown switch.
Note
When 37# and 38# are opened, the unit will be shut down.
Customized alarm terminal
Terminals 50#, 51# and 55# can be connected to three kinds of sensors, and terminal 24# is their common terminal,
and can be defined as smoke sensor and water-under-floor sensor. After the customer terminals are connected with
external alarm signals, you should set the corresponding customized alarm through the iCOM controller.
When the contact is open and no external alarm is generated, the input state of the customer terminal is open. But
when the contact is closed and the external alarm is generated, the input state of the customer terminal will be shorted.
At this point, the air conditioner system will generate an audible alarm, and the iCOM controller LCD will display the
alarm information.
Terminals 50# and 24#: Smoke detector alarm switch.
Terminals 37# and 38#: Remote alarm
Terminals 51# and 24#: Water-under-floor sensor by factory setting
External general alarm
Terminals 75# and 76# can be connected to the external general alarms. They output signals to external alarm devices,
such as alarm indicator. When critical alarm occurs, the contact will be closed to trigger remote alarms, send signals to
the building management system or dial the paging system automatically. The power supply of the external general
alarm system is user-prepared.
For the detailed definition of other terminals, refer to
4.2.4 Connecting Solenoid Valve Of Pipe Extension Kit (Options, For Site Installation)
The solenoid valve of the pipe extension kit has two control cables used to connect with the corresponding terminals of
the control board. The solenoid valve cables of 1# system and 2# system in dual system unit should be remarked
separately to avoid wrong connection. For specific wiring terminals in interface board, refer to the circuit diagram
printed on the unit label.
