Carrier 42LUVH055N Service Manual

208. Electronic function8.1 AbbreviationT1: Indoor ambient temperatureT2: Pipe temperature of indoor heat exchangerT3: Pipe temperature of outdoor heat exchangerT4: Outdoor ambient temperature8.2 Display function8.2.1 Icon explanation on indoor display board.42/38VHC121713G 42/38VHC124713G 42/38VHC128713G① Auto indicatorThis indicator illuminates when the air conditioner is in AUTO operation.② Timer indicatorThis indicator illuminates when TIMER is set ON/OFF.③ PRE.-DEF. IndicatorThis indicator illuminates when the air conditioner starts defrosting automatically or when the warm air control feature isactivated in heating mode.④ TEMPERATURE indicatorUsually it displays the temperature settings. When change the setting temperature, this indicator begins to flash, andstops 20 seconds later. It displays the room temperature when the air conditioner is in FAN only operation, and the rangeof that is 0~50℃. When the unit stops operation, it returns to original factory settings.Displays the malfunction code or protection code.⑤ Frequency indicatorThis indicator appears only when the compressor is in operation and indicates the current operating frequency.8.2.2 LED display control function.Pressing “LED display” button on remote controller will turn off all displays on indoor unit, while pressing once again, alldisplays will resume.8.3 Protection8.3.1 Three Minutes Delay at restart for compressor.8.3.2 Temperature protection of compressor top.If the temperature of compressor top is too high(higher than 115℃ and the Over-load Protector is cut, the units stop.When the Over-load Protector restore and close(lower than 100℃), the compressor will restart( in this case thecompressor is restricted by Three Minutes Delay protection.8.3.3 Temperature protection of compressor exhaust.If the exhaust temperature of compressor is higher than 115℃ and lasts for 5 seconds, the compressor stops and doesnot resume until the exhaust temperature is lower than 90℃.8.3.4 Inverter module Protection,