8
START-UP
General
Complete the start-up checklist on pages CL-1 and CL-2 before
attempting system start-up.
System Evacuation and Dehydration
Refer to GTAC II, Module 4, ‘‘Dehydration for Proper Evacuation
and Dehydration Techniques.’’
Charging Procedure
Before charging the system, install or replace the filter drier(s)
connected to the liquid line in the indoor unit to prevent contami
-
nation within the system. Refer to GTAC II, Module 5 “Charging,
Recovery, Recycling, and Reclamation” for proper charging tech
-
niques.
Low Ambient Operation (Factory Installed)
Refrigerant pressure controlled VFD (variable frequency drive)
adjusts fan speed to control head pressure. This fan speed control
permits unit to operate in cooling even in winter, when outdoor-air
temperature is down to 0°F.
The refrigerant pressure is measures by a discharge pressure trans
-
ducer that is factory-installed.
Configuration of Low Ambient Kit
(Field Installation)
The original unit should have the wiring diagrams as shown in the
typical wiring schematic in Troubleshooting section. The motor
start and wiring should be replaced with a 24-v relay and the VFD,
with the wiring shown in either the typical wiring schematic for
low ambient option (09XC06,08 units) or typical wiring schemat
-
ic for low ambient option (09XC12-24 units). Wiring diagrams are
provided in Troubleshooting section.
Be sure the VFD jumper wires are set as shown in the wiring dia
-
gram and the two DIP switches are set to the “0” position for volt
-
age control.
The parameters shown in Table 5 must be set for low ambient op
-
eration. Use actual nameplate motor FLA value since this value is
subject to change.
When the drive is installed and wired, it will be necessary to con
-
figure the drive for this application, as follows:
1. When the drive first starts, system will prompt to run the
Carrier Configuration Assistant. Exit this option.
2. Configure the drive parameters by pressing the menu button
and using the arrow keys to select “Parameters”, then press
the enter key.
3. Move to the appropriate sub-group using the arrow keys (first
two digits of the parameter to be changed), then press <SEL>.
4. Select the parameter to view or change using the arrow keys.
Change a parameter by scrolling to that parameter and press
-
ing <EDIT>.
5. Select the New Value, then press <SAVE>.
Table 5 —
Low Ambient Operation Parameters
Check Operation of Condenser Fan Motor
Controls and Rotation of Fans
Rotation should be clockwise as viewed from belt access panel.
Adjust Fan Speed
The 09XC units are belt-driven condenser units and allow for a
wide range of inlet static and condenser airflow requirements. It
may be necessary to adjust the condenser airflow to account for
these inlet conditions. Inadequate airflow will result in poor unit
performance and possible nuisance tripping of high-pressure
switches.
If an airflow is not specified, use the nominal airflow from Table 2
and adjust the fan speed to compensate for actual job conditions.
Use Tables 6-11 to determine proper fan speed. If the unit trips on
high pressure due to high condensing temperature, then it may be
necessary to increase the fan speed and condenser airflow.
CAUTION
To prevent injury, ensure that ducting or wire fan guards are
installed on the condenser fan before starting the unit.
PARAMETER
INDEX
PARAMETER FUNCTION
SELECTION
9902
Application Macro
1 (HVAC Default)
9906
Motor Nominal Voltage
Unit Voltage
(use value on nameplate)
9907
Motor Nominal Current
Motor FLA
(use value on nameplate)
9908
Motor Nominal Speed
1750
9909
Motor Nominal Power
Motor HP
(use value on nameplate)
1102
EXT 1 - EXT 2 SEL
EXT 2
1301
AI-1 Minimum
5%
1302
AI-1 Maximum
45%
1304
AI-2 Minimum
5%
1305
AI-2 Maximum
45%
1501
AO1 Content
122 (RO1-3 Status)
2007
FREQUENCY MIN
30.0 HZ
2202
Acceleration Time
10 s
2203
Decel Time
11 s
3404
OUTPUT 1
DISPLAY FORM
Direct
3408
OUTPUT 2
PARAMETER
PID 1 SETPOINT
3409
SIGNAL 2 MIN
0.0 PSI
3410
SIGNAL 2 MAX
667.0
3412
OUTPUT 2 UNITS
PSI
3413
OUTPUT 2 MIN
0.0 PSI
3414
OUTPUT 2 MAX
667.0
3415
OUTPUT 3 PARAMETER
PID 1 FEEDBACK
3416
SIGNAL 3 MIN
0.0 PSI
3417
SIGNAL 3 MAX
667 PSI
3419
OUTPUT 3 UNITS
PSI
3420
OUTPUT 3 MIN
0.0 PSI
3421
OUTPUT 3 MAX
667 PSI
4001
PID GAIN
0.7
4002
PID INTEGRATE
5 s
4003
DERIVATION TIME
DISABLE
4005
ERROR VALUE INVERTED
YES
4006
UNITS
PSI
4008
0% VALUE
0.0 PSI
4009
100 % VALUE
667 PSI
4010
SET POINT SELECT
INTERNAL
4011
INTERNALSET POINT
300.0
4014
Feedback Select
7 [Max(A1, A2)]
4017
ACT-2 Input
1 (AI1)
IMPORTANT: Check for proper fan rotation. If rotation needs
to be reversed, disconnect main power supply and switch any
2 leads at the load side of the disconnect switch.
