Lennox LNINVE052 Service Manual page 32

Service Manual
① If the unit is equipped with the remote controller with HEALTH button, the unit defaults health function ON. Health function will be
closed by pressing the HEALTH button on remote controller or turning off the unit.
② If the unit is equipped with the remote controller without HEALTH button, the unit defaults health function ON. Health function will be
closed when turning off the unit.
(2) I FEELfunction
When I FEEL command is received, the controller will operate according to the ambient temperature sent by the remote controller (For
defrosting and cold air prevention, the unit operates according to the ambient temperature sensed by the air conditioner). The remote
controller will regularly send ambient temperature data to the controller. When the data has not been received for a long time, the unit
will operate according to the temperature sensed by the air conditioner. If I FEEL function is not set, the ambient temperature will be that
sensed by the air conditioner.
5 Main system protection (more details please refer to maintenance section)
(1) Indoor fan motor does not operate (indoor unit displays H6 in cooling, heating, dry or fan mode)
If the controller detects that the rotation speed of indoor fan motor is below 300round/min or the indoor fan motor stops operation, it
judges that the motor operation is abnormal. In order to prevent damaging the motor, the system judges that the indoor fan motor is
blocked and then stops the unit for protection with error code displayed on the indoor unit (refer to Error Code List). After the unit is
turned off, the error code will not be displayed.
Turn off the unit and then turn it on, the malfunction display will be cleared.
(2) Freeze protection (indoor unit displays E2 in cooling or dry mode)
① In cooling and dry mode, if Tindoor pipe ＜ 0 ℃ is detected for 3min continuously, the outdoor unit will stop for freeze protection; if
Tindoor pipe ＞ 6℃ and the compressor has stopped for 3min, the unit will resume previous running status;
② In cooling and dry mode, if Tindoor pipe ＜ 6℃ , running frequency of compressor will be decreased or stop increasing;
③ If the unit stops for freeze protection for 6 times continuously, it can not resume operation automatically and displays error code; it can
resume operation by pressing ON/OFF button on the remote controller.
(3) Overload protection (indoor unit displays E8 in cooling, heating or dry mode)
① In cooling and dry mode: if Toutdoor≥65℃ ‚ the unit will stop for overload protection; if Toutdoor pipe ＜ 55℃ and the compressor has
stopped for 3min, the unit will resume previous running status;
② In cooling and dry mode: if Toutdoor pipe≥55℃ , running frequency of compressor will be decreased or stop increasing;
③ In heating mode: if Tindoor pipe≥64 ℃ , the unit will stop for overload protection; if Tindoor pipe ＜ 54 ℃ and the compressor has
stopped for 3min, the unit will resume running;
④ In heating mode: if Tindoor pipe≥55℃ , running frequency of compressor will be decreased or stop increasing.
(4) Compressor high discharge temperature protection (indoor unit displays E4 in cooling, heating or dry mode)
① If Tdischarge≥115 ℃ ‚ the unit will stop for high discharge temperature protection; if Tdischarge ＜ 97 ℃ and the compressor has
stopped for 3min, the unit will resume running;
② If Tdischarge≥97 ℃ ‚ running frequency of compressor will be decreased or stop increasing.
(5) Drop off voltage protection (indoor unit displays U3 in cooling, heating or dry mode)
During compressor operation, if voltage drops off rapidly, the system will stop running for drop off voltage protection; when the voltage
resumes normal, the malfunction will be eliminated automatically; if the compressor has stopped for 3min, the unit will resume previous
running status.
(6) Communication malfunction (indoor unit displays E6 in cooling, heating, dry or fan mode)
If the indoor unit and outdoor unit can not communicate smoothly, the unit will stop for communication malfunction; if communication
malfunction is eliminated and the compressor has stopped for 3min, the unit will resume previous running status.
(7) IPM module protection (indoor unit displays H5 in cooling, heating or dry mode)
① When the compressor starts, if there is overcurrent or low control voltage for IPM module due to some abnormal reasons, the unit will
stop for IMP module protection; when the IMP module current decreases or control voltage increases, the protection will be eliminated
automatically; if the compressor has stopped for 3min, the unit will resume previous running status.
② If unit stopping for module protection continuously occurs for three times, the unit can not resume running automatically and you
should press ON/OFF button on remote controller to resume running.
(8) Module overheating protection (indoor unit displays P8 in cooling, heating or dry mode)
① If Tmodule≥80℃ , running frequency of compressor will be decreased or stop increasing;
② If Tmodule≥95℃ , the unit will stop for module overheating protection; if Tmodule ＜ 87℃ and the compressor has stopped for 3min,
the unit will resume running.
Technical Information
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