Heatcraft Refrigeration Products H-IM-79B - Manual (Page 6)

6
WIRING (cont’d.)
• Multiple units – The multi-in and multi-out are the communication connections.
Connection sequence must follow the multi-out terminal to the multi-in terminal and
the multi-out back to the multi-in terminal in a daisy chain loop.
• Alarm circuit - The onboard alarm is a dry set of NC contacts which closes to indicate an
alarm. The type and wiring for the alarm is customer specified. Note that the alarm
circuit does not distinguish or indicate what has caused the alarm.
• All wiring must comply with all applicable codes and ordinances.
MULTIPLE EVAPORATOR CONFIGURATION (Master/Slave)
If there are multiple evaporators on a system, the program for each SLAVE evaporator
must be changed to identify it as a SLAVE. To do so, press the “PROGRAM REVIEW”
button repeatedly until “SLA” appears then use the “SELECT” knob to select “YES” then
press “ENTER”. All Beacon II boards are shipped with the factory default as a “MASTER”
evaporator. Place all boards in the “Service” mode while you program the setpoints to avoid
errors and alarms which may cause troubles at startup.
VERY IMPORTANT: This must be done for each slave board.
Up to 4 evaporators can be connected as a master/slave configuration. DO NOT remove
the room sensor from any of the Beacon II boards . This also applies when connected
to the optional Smart Controller.
Each Beacon II board power is supplied by a transformer in the evaporator on which it is
mounted. Do not run any 24 VAC wires between Beacon II boards on the evaporators.
Wiring/Configuration
CU
M S S S
M = Master Evaporator S = Slave Evaporator CU = Condensing Unit