Roof Top Units
HA / 34 /45 /52 /61 / 75 / 89 / 110 RC
Roof Top Unit
26
12 V
GND
1
2
ON/OFF
12 V
GND
1
2
RS485
TO OTHER
UNITS
Master
12 V
GND
1
2
Local
GND
1
2
RS485
NOTES
1. The local BMS must be configured to send
local temperature. This is done by selecting 1
zone and LCL in the set-up routine..
2. Unit address is set using DIP switches S9-S12
on the CAC controller.
3. Shielded cable is recommended for this control.
The RS485 communication wiring must be
twisted pair. Control wiring must be kept
separate from power wiring.
4. An “RT” or “Cont” alarm may appear in initial
start up. A signal from BMS will clear this
alarm.
5. The last controller change has priority. The unit
will then stay in that mode until another change
is sent either manually or by timer.
6. A maximum of 15 indoor units can be controlled
independently by one master controller.
MULTI UNIT AND LOCAL CONTROL USING UBMS
SINGLE AND TWO STAGE UNITS WITH CAC CONTROLLER
U BMS CONTROLLER
MASTER
U BMS CONTROLLER
LOCAL
CAC PCB
TERMINAL NUMBERS
OPTIONAL ON/OFF SWITCH
OR TIME CLOCK CONNECTION
U
U
