Carrier 48TC*D08 - Manual (Page 71)

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NOTE: The default value for the evaporator--fan motor
on/off delay is 45 seconds. The Integrated Gas Unit
Controller (IGC) modifies this value when abnormal limit
switch cycles occur. Based upon unit operating conditions,
the on delay can be reduced to 0 seconds and the off delay
can be extended to 180 seconds.
If the limit switch trips at the start of the heating cycle
during the evaporator on delay, the time period of the on
delay for the next cycle will be 5 seconds less than the
time at which the switch tripped. (Example: If the limit
switch trips at 30 seconds, the evaporator--fan on delay for
the next cycle will occur at 25 seconds.) To prevent
short--cycling, a 5--second reduction will only occur if a
minimum of 10 minutes has elapsed since the last call for
heating.
The evaporator--fan off delay can also be modified. Once
the call for heating has ended, there is a 10--minute period
during which the modification can occur. If the limit
switch trips during this period, the evaporator--fan off
delay will increase by 15 seconds. A maximum of 9 trips
can occur, extending the evaporator-fan off delay to 180
seconds.
To restore the original default value, reset the power to the
unit.
To shut off unit, set system selector switch at OFF
position. Resetting heating selector lever below room
temperature will temporarily shut unit off until space
temperature falls below thermostat setting.
Ventilation (Continuous Fan)
Set fan and system selector switches at ON and OFF
positions, respectively. Evaporator fan operates
continuously to provide constant air circulation. When the
evaporator-fan selector switch is turned to the OFF
position, there is a 30--second delay before the fan turns
off.
START--UP, PREMIERLINK
t
CONTROLS
Use the Carrier network communication software to start
up and configure the PremierLink controller.
Changes can be made using the ComfortWORKSr
software, ComfortVIEWt software, Network Service
Tool, System Pilott device, or Touch Pilott device. The
System Pilot and Touch Pilot are portable interface
devices that allow the user to change system set--up and
setpoints from a zone sensor or terminal control module.
During start--up, the Carrier software can also be used to
verify communication with PremierLink controller.
NOTE: All set--up and setpoint configurations are factory
set and field--adjustable.
For specific operating instructions, refer to the literature
provided with user interface software.
Perform System Check--Out
1. Check correctness and tightness of all power and
communication connections.
2. At the unit, check fan and system controls for proper
operation.
3. At the unit, check electrical system and connections
of any optional electric reheat coil.
4. Check to be sure the area around the unit is clear of
construction dirt and debris.
5. Check that final filters are installed in the unit. Dust
and debris can adversely affect system operation.
6. Verify that the PremierLink controls are properly
connected to the CCN bus.
Initial Operation and Test
Perform the following procedure:
1. Apply 24 vac power to the control.
2. Connect the service tool to the phone jack service
port of the controller.
3. Using the Service Tool, upload the controller from
address 0, 31 at 9600 baud rate. The address may be
set at this time. Make sure that Service Tool is
connected to only one unit when changing the
address.
Memory Reset
DIP switch 4 causes an E--squared memory reset to
factory defaults after the switch has been moved from
position 0 to position 1 and the power has been restored.
To enable the feature again, the switch must be put back
to the 0 position and power must be restored; this prevents
subsequent resets to factory defaults if the switch is left at
position 1.
To cause a reset of the non--volatile memory (to factory
defaults), turn the controller power off if it is on, move the
switch from position 1 to position 0, and then apply power
to the controller for a minimum of 5 seconds. At this
point, no action occurs, but the controller is now ready for
the memory to reset. Remove power to the controller
again and move the switch from position 0 to position 1.
This time, when power is applied, the memory will reset
to factory defaults. The controller address will return to
bus 0 element 31, indicating that memory reset occurred.
Refer to Rooftop PremierLink Installation, Start-Up, and
Configuration Instructions (Form 33CS--58SI) for full
discussion on configuring the PremierLink control system.
START--UP, RTU--MP CONTROL
Field Service Test, explained below, will assist in proper
start--up. Configuration of unit parameters, scheduling
options, and operation are also discussed in this section.
Field Service Test
The Field Service Test function can be used to verify
proper operation of compressors, heating stages, indoor
fan, power exhaust fans, economizer, and
dehumidification. Use of Field Service Test is
recommended at initial system start up and during
troubleshooting. See RTU--MP Controls, Start--Up,
Operation, and Troubleshooting Instructions (Form
48--50H--T--2T), Appendix A for Field Service Test Mode
table.
48TC