40
XC20
PUMP DOWN
PUMP DOWN
ON
OFF
ON
OFF
Figure 17. Pump-Down Jumper
4. Shut off the liquid line service valve to stop the flow of
refrigerant into the indoor coil.
5. After a three-second delay, the compressor and out
door fan will ramp up to 100% capacity. (Indoor fan will
remain
OFF.
)
6. Monitor the low-side pressure at the outdoor unit. The
internal vacuum protection in the compressor and/or
one of the pressure switches prevents full recovery of
the refrigerant into the outdoor unit. When the system
reaches this condition, the suction line service valve
should be shut off and the
Pump-Down Jumper
moved back to the
OFF
position.
NOTE -
The outdoor control will stay in pump-down mode
for five minutes, after which the outdoor control initiates a
compressor shutdown sequence.
7. Use a refrigerant recovery machine to recover the re
maining refrigerant on the indoor side of the system.
Table 8. Field Test, Diagnostic Recall and Program Menu Options
Display
Display and action (normal operation)
No Change - idle (*)
No Change - idle (*)
Solid
.
Enter or exit field test and program mode.
Solid
Puts unit in diagnostic mode. (Displays ambient, coil, liquid sensor temperatures and any active error codes.)
Solid
Clears error history (**)
Solid
Enter diagnostic recall mode. Displays up to 10 error codes in memory.
Solid
Starts outdoor fan.
String
Enter unit code programming.
*No change indicates the display will continue to show whatever is currently being displayed for normal operations.
**Note once the error history is deleted it cannot be recovered. After the history is deleted, the unit will reset itself.
Table 9. Normal Operation Character Display String
Display
Display and action (normal operation)
Display and action (configuration and test mode)
.
Idle mode — decimal flashes at 1 Hertz > 0.5 second ON, 0.5 second OFF
Cooling operation. Shows
and the cooling demand percentage. Example:
pause
pause
Fan RPM. Shows
and the current fan RPM. Example:
pause
pause
in the display string represents the active error code(s) in the outdoor unit.
Example:
pause
pause
pause
pause
pause
in the display string represents the outdoor ambient temperature in
F at the outdoor sensor on the outdoor unit.
Example:
pause
pause
If enabled,
in the display string represents the outdoor coil temperature in
F at the sensor on the outdoor unit.
Example:
pause
pause
pause
pause. Air conditioning units do not require an outdoor coil sensor. A 10K
resistor, across pins 5 and 6 on the outdoor control sensor harness, prevents false outdoor coil sensor codes. The 10K resistor
causes the 7-segment display to show a constant
77ºF
coil (c) temperature value.
If enabled,
in the display string represents the outdoor liquid line temperature in
F at the sensor on the outdoor unit.
Example:
pause
pause
pause
pause pause
pause
displays when system is in pump down mode.
TYPICAL 7-SEGMENT ACTIVE COOLING OR HEATING DEMAND DISPLAY STRING
COOLING AT
50% DEMAND
OUTDOOR
FAN RPM
OUTDOOR
AMBIENT AIR
TEMP
ACTIVE ERROR
CODE (IF PRESENT)
OUTDOOR
COIL TEMP(*)
OUTDOOR LIQUID
LINE TEMP
BY DEFAULT, COOLING OR HEATING, DEMAND, OUTDOOR FAN RPM, ACTIVE ERROR CODES
AND OUTDOOR AMBIENT TEMPERATURE ARE DISPLAYED.
OUTDOOR COIL AND LIQUID LINE TEMPERATURES CAN BE
MANUALLY ENABLED. IF SYSTEM POWER IS RECYCLED, DISPLAY
STRING REVERTS BACK TO DEFAULT (SEE FIGURE 19 TO ENABLE)
* Air conditioning units do not require an outdoor coil sensor. A 10K resistor, across pins 5 and 6 on the outdoor control sensor harness, prevents
false outdoor coil sensor codes. The 10K resistor causes the 7-segment display to show a constant
77ºF
coil (c) temperature value.
Figure 18. Typical 7-Segment Demand Display String
Содержание XC20-024-230-01
Страница 45: ...45 XC20 Unit Wiring Diagrams Figure 22 Typical Unit Wiring XC20 024 and 036...
Страница 46: ...46 XC20 Figure 23 Typical Unit Wiring XC20 048 and 060...
Страница 48: ...48 XC20 Factory Wiring Diagrams Figure 25 Typical Factory Wiring XC20 024 and 036...
Страница 49: ...49 XC20 Figure 26 Typical Factory Wiring XC20 048 and 060...
