Lennox MHA Series Service Manual

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whileoperatingtheairconditioner,turnofftheair
conditionerbeforedisconnectingthehose.
• Mountedthevalvestemcapsandtheserviceport.
Usetorquewrenchtotightentheserviceportcaptoa
torqueof18N·m(13.27ft·lbs).
• Alwaysleakcheckafterservicingtherefrigerant
system.
Thereareonelow-pressurecentralizedvalveandonehigh-
pressurecentralizedvalve,itwillbemoretimesavingwhen
vacuum and recycle refrigerant. But refer to the previous
instructionwhenvacuumandrecyclerefrigerant.
13. Electronic Function
13.1. Abbreviation
• T1:Indoorambienttemperature
• T2:Middleindoorheatexchangercoiltemperature
• T3:Outdoorheatexchangerpipetemperature
• T4:Outdoorambienttemperature
• T5:Compressordischargetemperature
13.2. Electric Control Working Environment.
• Inputvoltage:230V.
• Inputpowerfrequency:60Hz.
• Indoorfanstandardworkingamp.:<1A
• Outdoorfanstandardworkingamp.:<1.5A.
• Four-wayvalvestandardamp.:<1A
14. Adding Refrigerant - Single-Zone Systems
Theoutdoorunitisfactory-chargedwithrefrigerant.Calculate
theadditionalrefrigerantrequiredaccordingtothediameter
and the length of the liquid pipe between theoutdoorunit
andindoorunitconnections.
Besuretoaddtheproperamountofadditionalrefrigerant.
Failuretodosomayresultinreducedperformance.
See “Table 4. Line Set Guide” on page 26 for how much
refrigerantneedstobeaddedbasedonpipelength.
NOTE: Interconnecting pipe work between outdoor and
indoor units must be 10 ft. or longer.
NOTE: Do not remove refrigerant for line lengths less
than 25 ft. R-410A is a blended refrigerant. If you
must remove charge, it is necessary to remove
the entire charge and weigh in the new charge.
15. Single-Zone Outdoor Unit LED Locations
Single-zoneoutdoor unitsdisplay ashcodesonthemain
board.Themain boardisaccessedthroughthetopofthe
unit.Indoorunitswilldisplaymoredetailederrorcodes.
These outdoor units do not have a SW1 spot check push
button switch.Diagnosticisperformed through a series of
blue,redandgreenLEDs.
NOTE: The control on all single-zone outdoor units is
mounted with all LEDs down and cannot be seen
unless the control is removed.
Figure 24. Typical Location of Outdoor Unit LEDs

Lennox MHA Series Specifications

General

Brand	Lennox
Model	MHA Series
Category	Air Conditioner
Language	English