Lennox MHA Series Service Manual

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not operate in this mode. The Follow Me mode is
only available when a return air sensor is utilized.
Typically in most cases the Follow Me mode will
not be sufcient to remove excessive humidity.
NOTE: In addition, the outdoor units do not have a
humidistat installed therefore they are unable to
determine humidity levels. This product is not
recommend as a main source for dehumidication.
Note, this well over shoot the temperature by 6-8
degrees below what was set for dry mode.
NOTE: Using this mode will over shoot the temp by 6-8
degrees below what was set for dry mode.
6.3.2. Dry Mode Operation Sequence
Whenindry modeoperationthe unit isactuallyin cooling
modewithalowspeed bloweroperation.Thecompressor
willstopwhentheroomtemperatureistwodegreesCelsius
lowerthanthetemperaturesetting.
However there is a temperature compensation for cooling
modethatistwodegreesCelsius.Sotheunitwillstopwhen
thetemperatureisfourdegreesCelsiuslowerthantheroom
temperaturesettings.
NOTE: Four degrees Celsius is equivalent to 8°F
difference.
6.4. Test Run - Indoor Units
Onlyperformtestrunafteryouhavecompletedthefollowing
steps:
• ElectricalSafetyChecks–Conrmthattheunit’s
electricalsystemissafeandoperatingproperly
• GasLeakChecks–Checkallarenutconnectionsand
conrmthatthesystemisnotleaking
• Conrmthatgasandliquid(highandlowpressure)
valvesarefullyopen.
6.4.1. Test Run Instructions
YoushouldperformtheTestRunforatleast30minutes.
1. Connectpowertotheunit.
2. PresstheON/OFFbuttonontheremotecontrollertoturn
it on.
3. Press the mode button to scroll through the functions,
oneatatime:
4. Leteach function run forveminutes, and perform the
followingchecks:
6.4.2. Before Test Run
Table 3. Test Run Checklist
Checks Pass Fail
Noelectricalleakage
Unitisproperlygrounded
Allelectricalterminals
properlycovered
Indoorandoutdoorunits
aresolidlyinstalled
Allpipeconnectionpoints
donotleak
Waterdrainsproperlyfrom
drainhose
Allpipingisproperly
insulated
UnitperformsCOOL
functionproperly
Indoorunitlouversrotate
properly
Indoorunitrespondsto
remotecontroller
6.5. Double-Check Pipe Connections
Duringoperation,thepressureoftherefrigerantcircuitwill
increase.Thismayrevealleaksthatwerenotpresentduring
your initial leak check. Take time during the Test Run to
double-checkthatall refrigerantpipeconnection points do
nothaveleaks.
• Usingremotecontrol,returnunittothenormal
operatingtemperature.
• Usinginsulationtape,wraptheindoorrefrigerantpipe
connectionsthatyouleftuncoveredduringtheindoor
unitinstallationprocess.
6.6. Ambient Temperature is Below 63°F
(17°C)
You can’t use the remote controller to turn on the COOL
function when the ambient temperature is below 17°C. In
thisinstance,youcanusetheMANUALCONTROLbutton
totesttheCOOLfunction.
• Liftthefrontpaneloftheindoorunit,andraiseituntilit
clicksinplace.
• TheMANUALCONTROLbuttonislocatedontheright-
handsideoftheunit.Pressitonetimetoselectthe
COOLfunction.FirstpushisFCforcecooling,which
willdisplayonthewallunitasFCwhichisusedforhigh
speedcharging30minutetime.
• PerformTestRunasnormal.
• PushthebuttononetimeisforFCforcecooling,which
willdisplayedonwallunitasFC.Thisisusedforhigh
speedcharging30minutetime.
• Pushthebuttontwotimesforcoolingset75ºFandunit
isinautomode.Temperatureissetat75°Fwithno
changingofsettemperature..

Lennox MHA Series Specifications

General

Brand	Lennox
Model	MHA Series
Category	Air Conditioner
Language	English