Carrier 50SZ024 - Page 14

INDOORAIRFLOWANDAIRFLOWADJUSTMENTS
NOTE:Forcoolingoperation,therecommendedairflowis350to
450cfmforeach12,000Btuhofratedcoolingcapacity.Forunits
withoptionalelectricheat,theairflowmustnotbereducedbelow
thosestatedinTable2.
Table6showscoolingairflowsatvariousexternalstaticpressures.
Refertothistabletodeterminetheairflowforthesystembeing
installed.
NOTE:Besurethatallsupply-andreturn-airgrillesareopen,free
fromobstructions,andadjustedproperly.
ELECTRICALSHOCKHAZARD
Failuretofollowthiswarningcouldresultinpersonalinjury
ordeath.
Disconnectelectricalpowertntheunitandinstalllockouttag
beforechangingblowerspeed.
Airflowcanbechangedbychangingtheleadconnectionsofthe
blowermotor.
All50SZunitsarefactorywiredforlowspeed,exceptsizes030and
048whicharewiredformediumspeed.
FOR208/230V
Forcolorcodingonthe208/230Vmotorleads,seeTable4.
Table4--Color Coding lbr 208/230V Motor Leads
BLACK = HIGH SPEED
Blue = Medium Speed
Red = Low Speed
To change the speed of the indoor fan motor (IFM), remove the fan
motor speed leg lead from the time delay relay (TDR). This wire is
attached to terminal-3 of TDR for 3-phase units. To change the
speed, remove and replace with lead for desired blower motor speed.
Insulate the removed lead to avoid contact with chassis parts.
Metering
Position
Bypass
Position
INDOOR COIL
LEGEND
HPS - High Pressure Switch
LCS - Loss of Charge Switch
Accurate€ _ Metering Device
] Arrow indicates direction of flow
Fig. 16 - Typical Heat Pump Operation, Heating Mode
LEGEND
HPS - High Pressure Switch
LCS - Loss of Charge Switch
Accurater _'Metering Device
] Arrow indicates direction of flow
OUTDOOR COIL
Bypass
Position
C
Metering
Position
LCS
INDOOR COIL
>
C00095
Fig. 17 - Typical Heat Pump Operation, Cooling Mode
C00096
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