Lennox MHA Series Service Manual

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16. SpecicationsandOperations
Table 7. Electronic Functions Abbreviations
CN8 Indoorambienttemperature
CN9 Coiltemperatureofindoorheatexchanger
T3 Pipetemperatureofoutdoorheatexchanger
T4 Outdoorambienttemperature
T5 Compressordischargetemperature
Table 8. Electronic Control Working Environment
Inputvoltage:230V
Inputpowerfrequency:60Hz
Indoorfannormalworkingamp.islessthan1A
Outdoorfannormalworkingampislessthan1.5A
Four-wayvalvenormalworkingampislessthan1A
Table 9. Main Protection
Threeminutesdelayatrestartforcompressor
Oneminutedelayforthersttimestart-upandthreeminutesdelayforothers
Temperatureprotectionofcompressordischarge
Whenthecompressordischargeisgettinghigher,therunningfrequencywillbelimitedasbelowrules:
If215.6°F(102°C)<T5<244.4°F(115°C),decreasethefrequencytothelowerleveleverytwominutesuntiltoF1.
IfT5<244.4°F(115°C)fortenseconds,thecompressorwillstopandrestarttillT5<194°F(90°C)
Table 10. Indoor/Outdoor Units Communication Protection
Iftheindoorunitscannotreceivethefeedbacksignalfromtheoutdoorunitsfortwominutes,theunitwillstopanddisplayfailure.
HighCondenserColTemp
Protection
WhenT3>149°F(65°C)forthreeseconds,thecompressorwillstopwhiletheindoorfanandoutdoorfanwillcontinue.
WhenT3<125.6°F(52°C),theprotectionwillreleaseandthecompressorwillrestartafterthreeminutes.
RunningRules
IfthecompressorfrequencykeepslowerthanRET_OIL_FREQ1_ADDforRET_OIL_TIME1_ADD,theACwillrisethe
frequencytoRET_OIL_FREQ2_ADDforRET_OIL_TIME2_

Lennox MHA Series Specifications

General

Brand	Lennox
Model	MHA Series
Category	Air Conditioner
Language	English