EWWQ090G ÷ EWWQ720L - R410A - Water-cooled scroll chillers
EWLQ090G ÷ EWLQ720L - R410A - Condenser less
EWHQ100G ÷ EWHQ400G - R410A - Heat pump scroll chillers
EWAQ-
- R410A - Air-cooled scroll chillers
EWAQ-
- R410A - Air-cooled scroll chillers
EWYQ-
- R410A - Air-cooled scroll heat pumps
Air and Water cooled scroll chillers & heat pump
Operation
Manual
EWWQ - EWLQ - EWHQ
EWAQ - EWYQ
Air or Water cooled scroll chiller &
heat pump
D-EOMHW00107-15EN
Operation Manual
63
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The Slave unit that has lost the communication with the Master starts to operate as a
Standalone unit following all local settings
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The Master unit detects that there is a communication error with a Slave and if present
enable the Standby Chiller
-
If the Master unit loses the communication with all units of the network then all chiller will
work in standalone mode
5.10.4 Master Slave Options
5.10.4.1 Chiller Priority
Startup and shutdown of each chiller is managed by the Master based on the conditions reported
in the table below
Conditions Next Chiller to start
Next Chiller to stop
1
st
Highest priority
Lowest priority
2
nd
Lowest number of starts Lowest load
3
rd
Lowest running hours
Highest running hours
4
th
Lowest address
Highest number of starts
5
th
-
Lowest address
First condition is related to the priority defined for each chiller. The priority default values are all 1,
i.e. all unit have the same priority. A value of 1 indicates highest priority, a value of 4 indicates
lowest priority. The priority values can be modified on the Master chiller (refer to section 4.2.5.2)
5.10.4.2 Standby Chiller
Master Slave function allows to define one of the chillers belonging to the network as standby
chiller. The standby chiller is normally off and becomes operating only when one of the following
conditions occurs:
1. At least one chiller is in alarm state.
2. At least one of the Slave chillers is in communication alarm with the Master chiller.
3. At least one chiller is not enabled.
4. The function Temperature Compensation is enabled and the water temperature setpoint is
not reached with the system at full load.
In the following is explained step by step how to set all parameters changeable through the menu
4.2.5.1 to configure the standby chiller according to the local requirements.
Step 1 : Selection of the standby chiller.
Setpoint/Sub-
Menu
Default
Range
Description
