Danfoss AR05, Operation Instructions Manual, Page: 18 / 25

18 Reglermanual - VMGFF102
5  CONTROL OPERATION
5.1 - Start/stop control
The table below summarises the unit control type and stop
or go status with regard to the following parameters.
•
Operating type: this is selected using the start/stop
button on the front of the user interface.
LOFF: local off , L-C: local on, L-SC: local schedule, REM:
remote, CCN: network, MAST: Master
• Remote start/stop contacts: these contacts are used
when the unit is in remote operating type (Remote). See
sections 3.6.2 and 3.6.3.
• CHIL_S_S: this network command relates to the unit
start/stop when the unit is in network mode (CCN).
• Command set to Stop: the unit is halted.
• Command set to Start: the unit runs in accordance with
schedule 1.
• Start/Stop schedule: occupied or unoccupied status of
the unit as determined by the chiller start/stop program
(Schedule 1).
• Master control type. This parameter is used when the
unit is the master unit in a two chiller lead/lag arrange-
ment. The master control type determines whether the
unit is to be controlled locally, remotely or through CCN
(this parameter is a Service confi guration).
• CCN emergency shutdown: if this CCN command is
activated, it shuts the unit down whatever the active
operating type.
• General alarm: the unit is totally stopped due to failure.
5.2 - Heating/cooling/standby operation
5.2.1 - General
The heating/cooling/standby selection applies to all units.
But only liquid chiller units, controlling a boiler can change
over to heating mode. Heating/cooling control can be
automatic or manual.
In automatic mode the outdoor temperature determines the
heating/cooling/standby changeover based on the two
threshold values confi gured by the user (see RESETCFG menu
for cooling and heating mode changeover thresholds).
If the unit is in standby it does not cool or heat, and no
compressor can be activated. The diagram below summarises
the operating principle in automatic mode.
HEATING STANDBY COOLING
Outdoor
temperature
Heating
threshold* Cooling
threshold
* This threshold does not apply to cooling only units that do not control a boiler.
ACTIVE OPERATING TYPE STATUS OF PARAMETERS CONTROL
TYPE UNIT
MODE
LOFF L-ON L-SC rEM CCN MASt CHIL_S_S REMOTE
START/STOP
CONTACT MASTER
CONTROL
TYPE START/STOP
SCHEDULE
MODE CCN
EMERGENCY
SHUTDOWN GENERAL
ALARM
- - - - - - - - - - Enable - - Off
- - - - - - - - - - - Yes - Off
Active - - - - - - - - - - - Local Off
- - Active - - - - - - Unoccupied - - Local Off
- - - Active - - - Off - - - - Remote Off
- - - Active - - - - - Unoccupied - - Remote Off
- - - - Active - Disable - - - - - CCN Off
- - - - Active - - - - Unoccupied - - CCN Off
- - - - - Active - - Local Unoccupied - - Local Off
- - - - - Active - Off Remote - - - Remote Off
- - - - - Active - - Remote Unoccupied - - Remote Off
- - - - - Active Disable - CCN - - - CCN Off
- - - - - Active - - CCN Unoccupied - - CCN Off
- Active - - - - - - - - Disable No Local On
- - Active - - - - - - Occupied Disable No Local On
- - - Active - - - On cooling - Occupied Disable No Remote On
- - - Active - - - On heating - Occupied Disable No Remote On
- - - Active - - - On auto - Occupied Disable No Remote On
- - - - Active - Enable - - Occupied Disable No CCN On
- - - - - Active - - Local Occupied Disable No Local On
- - - - - Active - On cooling Remote Occupied Disable No Remote On
- - - - - Active - On heating Remote Occupied Disable No Remote On
- - - - - Active - On auto Remote Occupied Disable No Remote On
- - - - - Active Enable - CCN Occupied Disable No CCN On