Lennox MCA Series Service Manual

14
7.2. Indoor Unit Connection Points for
Centralized Controller
Mini-split indoor units can be connected to a centralized
controller(e.g.LennoxVRFManager-LVMorTraneTracer)
oraBACnetorLonWorksgatewayusingtheXYEterminals
ontheindoorunitmainboard.
To CCM
Comm.Bus
X Y
(
E
)
Y/G
Figure 15. Indoor Unit Connection Points
(Typical Wiring Diagram)
Figure 16. Typical Indoor Unit Connection Points
7.3. Dry Mode Operation - Indoor Units
7.3.1. Procedure
1. PresstheMODEbuttontoselectDRY mode.
2. Press the UP/ DOWN button to select the desired
temperature.Thetemperaturesettingrangeisfrom62°F
to86°Finonedegreeincrements.
NOTE: The blower is preset at a low speed and cannot be
changed therefore it will get cold and most likely
will over shoot the temperature setting by 6-10
degrees depending on the room size or other
various factors. Also the Follow Me mode does
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.
7.3.2. 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.
7.4. 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.
7.4.1. 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:
7.4.2. 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

Lennox MCA Series Specifications

General

Brand	Lennox
Model	MCA Series
Category	Air Conditioner
Language	English