27
Table 20 — Unit States
Table 21 summarizes the unit control method and stop or go
status with regard to the following parameters set in the Carrier
Controller module:
• Machine Control Method: Machine Control Method as se-
lected on the unit Start/Stop screen.
• CHIL_S_S: Current CCN chiller start/stop force com-
mand (enable/disable). Main Menu
General Parame-
ters
Net:Cmd Start/Stop.
• ONOFF_SW: Start-stop contact status when unit is under re-
mote operating type. Main Menu
Inputs Status
Re-
mote On/Off Switch.
• CHIL_OCC: Chiller occupied state. If the occupancy
override input switch is closed, the chiller remains occu-
pied regardless of the set point scheduled selection. Main
Menu
General Parameters
Net:Cmd Occupied.
• MS_CTRL: Master control type. This parameter status will
determine if the master unit is going to be controlled locally,
remotely, or through CCN. Main Menu
Maintenance
Menu
Master Slave Control (0=disabled, 1=master,
2=slave).
• EMSTOP: CCN emergency stop command (enable/disable).
Main Menu
General Parameters
Emergency Stop.
• Alarm shutdown: Unit is totally stopped due to alarm.
The Machine Control Method and Parameter Status combina-
tions listed in Table 21 will determine the actual unit running
state.
NOTE: When changing from one Machine Control Method
(Local On, Local Schedule, Network, Remote, or Master) to
another, the unit will observe a transition through the Off state
before being allowed to start again. At this time the on-to-off
delay is always applied.
Chilled Water Set Point Configuration
The chilled water set point and fluid type configuration will de-
termine the chiller operating conditions.
FLUID SET POINT CONTROL LOCATION
The factory default for the chilled water fluid set point is to
control to the leaving water temperature. An option to config-
ure the machine for entering water control is available. To con-
figure this option go to Main Menu
Configuration Menu
Service Parameters. The default for Entering Fluid Con-
trol is Off (leaving fluid control is the default condition). To
enable Entering Water Control, change Entering Fluid Con-
trol to On. Entering Water Control is recommended for con-
stant flow applications only.
COOLING SET POINT SELECTION
The Control Point (shown in the lower right corner of the Home
Screen, or Main Menu
General Parameters
Control
Point) represents the water temperature that the unit must pro-
duce. The unit will vary the capacity depending on the load condi-
tions in order to satisfy the set point. The Control Point
(CTRL_PNT) is calculated based on the Active Setpoint (Main
Menu
General Parameters) [Main Menu and General Param-
eters in bold italics]. and the reset calculation, where Control Point
= Current Setpoint + Temperature Reset. (See “Temperature Re-
set” on page 38.) Control Point can be written to by the Building
Management System, instead of the set point calculation only if
Network is selected as the Machine Control Method for the unit.
See Main Menu
General Parameters
Local=0 Net.-1 Re-
mote=2 to verify operating type.
Table 21 — Start/Stop Control
LEGEND
STATE DESCRIPTION
Off Unit is commanded to be off
Stopping
Unit is currently stopping (after a manual, emergency, or
shutdown request). Next state will be Off.
Delay
Unit is in delay at start-up (waiting for the end of the On/Off
delay to be reached). Next state will be Running.
Running
Unit compressor capacity is more that 0% (unit has started
running)
Ready Unit compressor capacity is 0%. Unit is ready to start.
Override
The compressor cannot start because of an override (SST,
SCT, etc.)
Tripout Unit is Off due to an alarm
Test Unit is in Quick Test
MACHINE CONTROL METHOD PARAMETER STATUS
OPERATING
TYPE
UNIT
STATUS
CHIL_S_S ONOFF_SW MS-CTRL CHIL_OCC EMSTOP
Alarm
Shutdown
Local Off ——————LocalOff
Local On — — — — Disable No Local On
Local Schedule — — — Yes Disable No Local On
— — — No — — Local Off
Remote —Open————RemoteOff
———No——RemoteOff
Closed Yes — — Remote On
CCN Disable — — — — — CCN Off
———No——CCNOff
Enable — — Yes Disabled No CCN On
Master — — Local No — — Local Off
— Open Remote — — — Remote Off
— — Remote No — — Remote Off
Disable — CCN — — — CCN Off
— — CCN No — — CCN Off
— — Local Yes Disable No Local On
— Closed Remote Yes Disable No Remote On
Enable CCN Yes Disable No CCN On
—
————
Enable — — Off
—Yes— Off
CHIL_OCC — Chiller Occupied State MA St — Master/Slave Operating Type
CHIL_S_S — CCN Chiller Start/Stop Command MS-CTRL — Master/Slave Control
EMSTOP — Emergency Stop ONOFF_SW — Remote On/Off Switch
To Next Page
Loading...
Need help?
General