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INSTALLATION INSTRUCTIONS
6. If LPS or HPS trips 3 consecutive cycles, the unit
operation is locked out for 4 hours.
7. In the event of a high pressure switch trip or high
pressure lockout, check the refrigerant charge outdoor
fan operation and outdoor coil for airflow restrictions.
8. In the event of a low pressure switch trip or low
pressure lockout, check the refrigerant charge and
indoor airflow.
Control Fault
If the outdoor unit control board has failed, the control will
flash the appropriate fault code. (See Table 6) The control
board should be replaced.
Brown Out Protection
If the line voltage is less than 187v for at least 4 seconds, the
appropriate compressor contactor and fan relay are
de-energized.
Compressor and fan operation are not allowed until voltage is
a minimum of 190v. The control will flash the appropriate fault
code (see Table 6)
230 V Brown Out Protection Defeated:
The brownout feature can be defeated if needed for severe
noisy power conditions. This defeat should always be a last
resort to solving the problem. Defeat can be initiated through
the forced defrost pins as follows:
The brownout toggle is accomplished by shorting the defrost
pins from power up with the OAT and OCT sensor connector
removed.
After 3 seconds, the status of the force defrost short and the
OAT/OCT as open will be checked. If correct, then the
brownout will be toggled.
S
Status code 6 shows the brownout is disabled.
S
Status code 5 shows the brownout is active.
After the brownout defeat is set, power down and reinstall the
OAT/OCT sensor and remove the short from the forced
defrost pins. As long as the short on the forced defrost
remains, the OAT and OCT faults will not be cleared. The
code will continue to be flashed.
The control is shipped with the brownout active. The change
in status is remembered until toggled to a new status. A
power down/power up sequence will not reset the status. It
may be necessary to do the toggle twice to cycle to the
desired state of the defeat.
230V Line (Power Disconnect) Detection
If there is no 230v at the compressor contactor(s) when the
indoor unit is powered and cooling demand exists, the
appropriate error code is displayed (see Table 6). Verify that
the disconnect is closed and 230v wiring is connected to the
unit.
Compressor Voltage Sensing
The control board input terminals labeled VS and L2 (see
Fig. 10) are used to detect compressor voltage status, and
alert the user of potential problems. The control continuously
monitors the high voltage on the run capacitor of the
compressor motor. Voltage should be present any time the
compressor contactor is energized, and voltage should not
be present when the contactor is de−energized.
Contactor Shorted Detection
If there is compressor voltage sensed when there is no
demand for compressor operation, the contactor may be
stuck closed or there is a wiring error. The control will flash
the appropriate fault code.
10
R−410A Split System Air Conditioner
Compressor Thermal Cutout
If the control senses the compressor voltage after start−up,
and is then absent for 10 consecutive seconds while cooling
demand exists, the thermal protector is open. The control
de−energizes the compressor contactor for 15 minutes, but
continues to operate the outdoor fan.
The control Status LED will flash the appropriate code shown
in Table 6. After 15 minutes, with a call for low or high stage
cooling, the compressor contactor is energized. If the thermal
protector has not reset, the outdoor fan is turned off. If the call
for cooling continues, the control will energize the
compressor contactor every 15 minutes. If the thermal
protector closes, (at the next 15 minute interval check), the
unit will resume operation. If the thermal cutout trips for three
consecutive cycles, then unit operation is locked out for 4
hours and the appropriate fault code is displayed.
No 230V at Compressor
If the compressor voltage is not sensed when the
compressor should be starting, the appropriate contactor
may be stuck open or there is a wiring error. The control will
flash the appropriate fault code. Check the contactor and
control box wiring.
Troubleshooting units for proper switching
between low & high stages
Check the suction pressures at the service valves. Suction
pressure should be reduced by 3−10% when switching from
low to high capacity.
NOTE: The liquid pressures are very similar between low and
high stage operation so liquid pressure should not be used
for troubleshooting.
Compressor current should increase 20−45% when switching
from low to high stage. The compressor solenoid, when
energized in high stage, should measure 24vac across pin
numbers PL5−2 HI and PL5−5 C. When the compressor is
operating in low stage the 24v DC compressor solenoid coil
is de−energized. When the compressor is operating in high
stage, the 24v DC solenoid coil is energized. The solenoid
plug harness that is connected to the compressor has an
internal rectifier that converts the 24v AC signal to 24v DC.
NOTE: DO NOT INSTALL A PLUG WITHOUT AN
INTERNAL RECTIFIER.
Unloader Test Procedure
The unloader is the compressor internal mechanism,
controlled by the DC solenoid, that modulates between high
and low stage. If it is suspected that the unloader is not
working, the following methods may be used to verify
operation.
1. Operate
the
system
amperage. Cycle the unloader on and off at 30 second
plus intervals at the Wall Control (from low to high
stage and back to low stage). Wait 5 seconds after
staging to high before taking a reading. The
compressor amperage should go up or down at least
20 percent.
2. If step one does not give the expected results, remove
the solenoid plug from the compressor and, with the
unit running and the Wall Control (or Thermostat)
calling for high stage, test the voltage output at the
plug with a DC voltmeter. The reading should be 24
volts DC.
3. If the correct DC voltage is at the control circuit molded
plug,
measure
the
resistance. The resistance should be 32 to 60 ohms
depending on compressor temperature. If the coil
and
measure compressor
compressor
unloader
coil
421 01 1701 00
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