Operation; Sequence Of Operation; Low Ambient Start; Snow Clearing - Carrier 09FC020 Installation, Start-Up And Maintenance Instructions

SCREEN NAMES
Time Master

Operation

SEQUENCE OF OPERATION

When the unit is in an occupied mode, SW1 is in the Local
position or in the Remote position with 24 vac applied to the
Remote Contact Relay, R3. Once enabled the AppController will
determine if the conditions are favorable to use free cooling. If so,
the 3-way valve will move from the bypass position to free
cooling. This will route water through the coils. At the same time
the fan will ramp to full speed. If LWT is above the setpoint, fans
will stay at full speed. If not, the fans will reduce speed to control
to the LWT setpoint. If the outdoor air temperature continues to
drop and the LWT falls below setpoint with the fans at 0 Hz, the 3-
way valve will adjust to mix return water and water from the coils
to keep LWT from going too low. The opposite sequence will
occur as the outdoor air temperature increases.
Any alarms or loss of the enable signal will cause the valve to
move to bypass mode and the fans to stop.

LOW AMBIENT START

The water in the unit will move to outdoor air temperature when
unit is not running. If unit has not run for 1 hr. and outdoor air tem-
perature is more than 30°F below the LWT setpoint, the valve will
open slightly to mix return water with free cooling water for a pe-
riod of time before going into full free cooling mode. This will
prevent low temperature spikes from entering the building.

SNOW CLEARING

At temps below 34°F the fans will go to full speed for 15 seconds
each time the unit goes into free cooling mode.

START-UP

Verify the LWT setpoint and OAT setpoint are correct for the ap-
plication. See Field Configuration section.
Table 16 — Required Configurations (cont)
DISPLAY/DETAILS
If the Equipment Touch is serving as the front-end for your system, you should designate a controller to be the
BACnet Time Master. If a controller will be the BACnet Time Master, this screen lets you configure how it sends
time synchronization broadcasts.
Time Sync Mode - Tap in the number below that represents your selection:
• 0 = No Broadcast - The controller will not act as Time Master.
1 = Local Broadcast - If it doesn't already exist, a BACnet address with network number and MAC ad-
•
dress length both set to zero is added to the controller's Time Synchronization Recipients list found on
the driver's Device page in the i-Vu
ler on its ARCnet or MS/TP network.
• 2 = Global Broadcast - If it doesn't already exist, a global address with network number set to 65535 and
MAC address length set to zero is added to the controller's Time Synchronization Recipients list found
on the driver's Device page in the i-Vu interface. The controller will then send time broadcasts to all its con-
nected networks.
Time Sync Interval - Enter how often local or global time broadcast should be sent (1-9999 minutes). If Time
Sync Interval is set to zero, no time sync messages are sent.
NOTE: If the controller looks through its Time Synchronization Recipient List and finds an entry with MAC
address length set to zero and network number set to 65535, the controller's BACnet Time Master mode is set
for Global Broadcast. If there is no global broadcast entry in the recipient list, the controller then looks for a local
broadcast address (MAC address length set to zero and network number set to zero or to the same network
number as the module's). If such an entry is found, the BACnet Time Master mode is set for Local Broadcast.
Otherwise, the mode defaults to Disable/None.
interface. The controller will then send time broadcasts only to control-
®
Flowrate should be set with the 09FC unit in free cooling mode.
This mode will have a larger pressure drop than the bypass mode.
Setting the flow in this mode assures the chiller will always have
the minimum flow required for operation.
Start the chilled water pump.
Complete the Start-Up Checklist to verify all components are op-
erating properly.
Set SW2 toggle switch to ENABLE. This will power the controls.
The switch is behind the left door of the control panel. This side of
the panel only contains 24Vac, no line voltage.
Check inputs on the display to verify all temps are reading correct-
ly. Reference the Carrier Equipment Touch section of this manual.

Alarms

NON-OPERATIONAL COMPONENT ALARM

If (LWT  Cooling Lockout Temp + Cooling Lockout Offset +
Non-Operational Component Alarm Offset) and (Unit is in free
cooling mode for 3 minutes), alarm contact will close, valves will
drive to bypass position, and fans will stop. This alarm detects
equipment failures.
Manual reset.

REVERSE LOAD WATER FLOW ALARM

[If (LWT  EWT + Reverse Load Water Flow Alarm Temp Diff)
and (bypass valve is open, to free cool)] for 3 minutes. Alarm con-
tact will close, valves will drive to bypass position, and fans will
stop. This alarm detects reverse water flow or reversed sensors.
Manual reset.
53

SERVICE