Chapter 3 Electrical Installation 25
DataMate 3000 Series Air Conditioner User Manual
3.4.3 General Alarm
Terminal J10 is for general alarm output. It connects the general alarm relay that
provides a set of normally open dry contacts, which will close when a major alarm
is registered. It can be used to raise an alarm in a remote location, or signal a
building management system or auto-dialing pager system.
3.4.4 Changeover And Standby Unit Enable
Terminals J9 and J18 are for duty/standby system changeover terminal and
standby system enable terminal. Two systems can be linked so that one is a ‘duty’
system and the other is a ‘standby’ system. The connection is shown in Figure 3-6.
Duty/standby unit
changeoverJ9
Duty/standby unit
changeover J9
Standby unit
enable J18
Standby unit
enable J18
Duty unit
Standby unit
Figure 3-6 Duty/standby mode connection
3.4.5 Monitoring Interface
The RS485 port is on the back of the evaporator front door under a protective plate.
Remove the plate first and connect this port to a host with a twist-pair
communication cable, as shown in Figure 3-7.