CLIMATIC™ 50 User manual - Lennox

COMMUNICATION
MASTER/SLAVE
Function
Link several units in order to allow a “Master/Slave” relationship between each units.
Description
Configuration of the pLan network
To configure the addresses of the cards for the pLan network, see chapter: (Configuring the pLan address of the BM50)
For the pLan network, each unit must have a different address:
Unit 1 � Master unit
Units 2 to 12 � Slave units
Master/Slave Modes
Several master/slave modes are available and may be configured by using set points 3922 and 3923:
Cold/hot Master/Slave mode:
All the units are stand-alone, but:
• If the master is calling for cooling, the heating adjustment of the slaves is inhibited.
• If the master is calling for heating, the cooling adjustment of the slaves is inhibited.
“Token” Mode:
This mode limits the number of compressors in operation.
Use set point 3922 to set the maximum number of compressors that can operate simultaneously for all the units
connected.
Back-up mode;
The unit with the highest pLan address is used as a back-up in the event of a fault in another unit.
In the event of different faults on several units, the following fault priority is applied:
1. The unit stops
2. Fault in one sensor or probe
3. Fault in one or more compressors
4. Fault in a back-up heater
5. Temperature Limit fault
6. Filter fault
If the ambient temperature is exceeded, fault 013 or 023, the back-up unit will restart to compensate for the loss of power
of the other units.
Rotating back-up mode:
Same as above, except the "back-up" unit changes every Tuesday at 09.00 if none of the other units is faulty.
Master DC50
Function configurable using set point 3924:
Activation of this function enables one, and only one, DC50 to be connected for a maximum of 12 units.
• The DC50 must be connected to the Master unit (pLan address 1).
• The functions between the Master BM50 and its DC50 are standard.
• The Master BM50 communicates its Start or Stop status to its slaves, the current range and the values
of its temperature and minimum fresh air set points.
• The slaves BM50s communicate a summary of their Alarms to the master. A 902 alarm on the master unit
represents activation of a fault on slave unit 2 (903 for 3, etc).
This function is incompatible with the Back-up mode.
CLIMATIC50 – IOM – Rooftops/ Aircoolair CL50-ROOFTOPS-IOM-1107-E 43