heatcraft-refrigeration-p h-im-79d User Manual

•   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.

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.

M = Master Evaporator

S = Slave Evaporator

CU = Condensing Unit