INSTALLATION INSTRUCTIONS
R
−
410A Split System Air Conditioner
10
421 01 5104 02
Specifications subject to change without notice.
TROUBLESHOOTING
SYSTEMS COMMUNICATION FAILURE
If communication between outdoor unit, control board, and
indoor wall control has failed, the control will flash the
appropriate fault code. (See table 3) Check the wiring to the
wall control, indoor and outdoor units.
PRESSURE SWITCH PROTECTION
The outdoor unit is equipped with high
−
and low
−
pressure
switches. If the control senses the opening of a high or
low
−
pressure switch, it will de
−
energize the compressor
contactor, keep the outdoor fan operating for 15 minutes and
display the appropriate fault code. (See table 3)
After a 15 minute delay, if there is still a call for cooling, and
the LPS or HPS is reset, the compressor contactor is
energized. If the LPS or HPS has not closed after a 15
minute delay, the outdoor fan is turned off. If the open switch
closes anytime after the 15
−
minute delay, then the unit will
resume operation with a call for cooling.
If the LPS or HPS trips for five consecutive cycles, then unit
operation is locked out for 4 hours and the appropriate fault
code (See table 3) is displayed.
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.
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 3) The control
board should be replaced.
24V BROWN OUT PROTECTION
If the control voltage is less than 15.5volts for at least 4
seconds, the compressor contactor and fan relay are
de
−
energized. Compressor and fan operation are not
allowed until control voltage is a minimum of 17.5volts. The
control will flash the appropriate fault code. (See table 3)
Verify the control voltage is in the allowable range of
18
−
30volts.
COMPRESSOR VOLTAGE SENSING
The input terminals labeled VR and VS on the control board
(see Fig. 9) 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.
COMPRESSOR THERMAL CUTOUT OR LOSS OF
230V POWER
If the control senses the compressor voltage after start
−
up,
and is then absent for 10 consecutive seconds while cooling
demand exists, it will de
−
energize the compressor contactor,
keep the outdoor fan operating for 15 minutes (if 230v power
present) and display the appropriate fault code. (See table 3)
Possible causes are compressor internal overload trip or loss
of high voltage (230V) to compressor without loss of control
voltage.
After a 15 minute delay, if there is still a call for cooling, the
compressor contactor is energized. If the thermal protector
has not re
−
set, 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 (See Table 3) is displayed.
CONTACTOR SHORTED DETECTION
If there is compressor voltage sensed when there is no
demand for compressor operation, the contactor may be
stuck closed. The control will flash the appropriate fault
code. Check the contactor and control box wiring.
NO 230V AT COMPRESSOR
I f t h e c o m p re s s o r v o l t a g e i s n o t s e n s e d w h e n t h e
compressor should be starting, the contactor may be stuck
open or the unit disconnect or circuit breaker may be open.
The control will flash the appropriate fault code. Check the
contactor, unit disconnect or circuit breaker and control box
wiring.
TEMPERATURE THERMISTORS
Thermistors are electronic devices which sense temperature.
As the temperature increases, the resistance decreases.
Thermistors are used to sense outdoor air (OAT) and coil
temperature (OCT).
If the outdoor air or coil thermistor should fail, the control will
flash the appropriate fault code. (See table 3).
IMPORTANT
: The outdoor air thermistor and coil thermistor
are factory mounted in the correct locations. Do not re
−
locate
thermistor sensors.
THERMISTOR SENSOR COMPARISON
The control continuously monitors and compares the outdoor
air temperature sensor and outdoor coil temperature sensor
to ensure proper operating conditions. The comparison is, if
the outdoor air sensor indicates
≥
10
_
F (
≥
−
12.22
_
C) warmer
than the coil sensor (or) the outdoor air sensor indicates
≥
20
_
F (
≥
−
6.67
_
C) cooler than the coil sensor, the sensors
are out of range.
If the sensors are out of range, the control will flash the
appropriate fault code. (See Table 3).
FAILED THERMISTOR DEFAULT OPERATION
Factory defaults have been provided in the event of failure of
outdoor air thermistor and/or coil thermistor.
Thermistor Curve: The resistance vs. temperature chart
shown in Figure 8 enables the technician to check the
outdoor air and outdoor coil thermistors for proper resistance.
Unplug the thermistor assembly from the circuit board and
measure resistance across each thermistor. For example, if
the outdoor temperature is 60
_
F (15.56
_
C), the resistance
reading across the outdoor air thermistor should be around
16,000 Ohms.
STATUS CODES
Table 3 shows the status codes flashed by the amber status
light. Most system problems can be diagnosed by reading
the status code as flashed by the amber status light on the
control board.
The codes are flashed by a series of short and long flashes
of the status light. The short flashes indicate the first digit in
the status code, followed by long flashes indicating the
second digit of the error code. The short flash is 0.25 second
ON and the long flash is 1.0 second ON. Time between
flashes is 0.25 second. Time between short flash and first
long flash is 1.0 second. Time between code repeating is 2.5
seconds with LED OFF.
Count the number of short and long flashes to determine the
appropriate flash code. Table 3 gives possible causes and
actions related to each error.
