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Service Manual -
HRG18xxS1P
508206-01
Issue 2140
Page 71 of 83
DC Inverter Control Operation, Checkout, Status / Error Codes
OPERATION OF COMPONENTS:
Electromagnetic compatibility circuit (EMC): EMC ensures the correct operation of different equipment items which use or
respond to electromagnetic phenomena. It also helps to negate the effects of interference.
CONVERTER:
Converts AC (alternating current) to DC (direct current).
POWER FACTOR CORRECTION (PFC) CIRCUIT:
The PFC module is an integrated part of the outdoor inverter that monitors the DC bus for high, low and abnormal voltage
conditions. If any of these conditions are detected, the PFC function and compressor will stop.
INTELLIGENT (INVERTER) POWER MODULE (IPM):
The IPM converts DC power into AC power. The control method is known as pulse width modulation (PWM). This means
the DC is switched on and off very quickly (chopped) by the transistor switches to make simulated AC at required frequency
and voltage.
COMMUNICATION CONTROL CIRCUIT:
Receives and sends message between the inverter and the outdoor control.
NOTE - System fault and lockout codes take precedence over system status codes (cooling, heating operating percentages or defrost/dehumidification). Only the latest
active fault or lockout codes are displayed (if present). If no fault or lockout codes are active, then system status codes are displayed. Alert codes are also displayed on the
communicating thermostat.
GF= Gas Furnace, AH=Air Handler, ID=Indoor unit (GF or AH), HP=Heat Pump, AC=Air Conditioner, OD=Outdoor Unit (AC or HP), ZA=Zone system and TS=Thermostat
Alert
Code
Inverter
Flash
Code
Priority
Condition
Actual Displayed
Alert Text
Component or System Operational State and Troubleshooting Tip
How to Clear Alert
Code
180
Service
Soon
Outdoor Tem-
perature Sensor
Problem
The thermostat has found a problem with the outdoor sensor in the outdoor
unit or the optional outdoor sensor connected to the indoor unit. In normal
operation after system component control recognizes sensors, the alert code
will be sent if valid temperature reading is lost.
• Compare outdoor sensor resistance to temperature / resistance charts in unit
installation instructions. Replace sensor pack or stand alone outdoor sensor.
• At the beginning of (any) configuration, furnace, air-handler control or
equipment interface module will detect the presence of the sensor(s).
• If detected (reading in range), appropriate feature will be set as ‘installed’ and
shown in the ‘About’ screen.
Automatically
clears upon config-
uration, or sensing
normal values.
182
Service
Soon
OD Suction
Temperature
Sensor Fault
• Reading below 0.25V or above 4.75V for 24hrs +/- 3hrs. System will
continue to operate normally.
Resets after 3 con-
secutive readings
that are in range.
183
Service
Soon
OD Liquid Pres-
sure Sensor
Fault
• Under 0.25V and above 4.75V readings for 24 hours +/-3hrs or more on the
sensor will cause this error.
• Continue normal operation, see sections related to low pressure switch
emulation for specific details related to low pressure switch faults.
Resets after 3 con-
secutive readings
that are in range.
424
Service
Soon
OD Liquid Line
Sensor Faulty
The liquid line temperature sensor has malfunctioned.
• In normal operation after outdoor control recognizes sensors, the alert code
will be sent if a valid temperature reading is lost.
• Compare liquid line sensor resistance to temperature / resistance charts in
unit installation instructions.
• Replace sensor pack if necessary.
• At the beginning of (any) configuration, furnace or air handler control will
detect the presence of the sensor(s).
• If detected (reading in range), appropriate feature will be set as ‘installed’ and
shown in the thermostat ‘About’ screen.
Automatically
clears upon config-
uration, or sensing
normal values.
Table 23. Outdoor Control 7-Segment Display Alert Codes – Outdoor Control Errors