Carrier 38BYW, Installation And Start-Up Instructions Manual

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Table 2—Accessory Usage
ACCESSORY
REQUIRED FOR
LOW-AMBIENT
APPLICATIONS
(BELOW 55°F)
REQUIRED FOR
LONG-LINE
APPLICATIONS*
(OVER 50 FT)
REQUIRED FOR
BURIED LINE
APPLICATIONS†
(OVER 3 FT)
Crankcase Heater Yes Yes Yes
Evaporator Freeze Thermostat Yes No No
Accumulator No No Yes
Compressor Start Assist
Capacitor and Relay
Yes Yes Yes
Low-Ambient Controller,
MotorMaster® Control,
or
Low-Ambient Pressure Switch
Yes No No
Wind Baffle See Low-Ambient Instructions No No
Unit Risers Recommended No No
Liquid-Line Solenoid Valve
or
Hard Shutoff TXV
No
See Long-Line
Application
Guideline
Yes
Ball Bearing Fan Motor Yes‡ No No
* For tubing line sets between 50 and 175 ft, refer to Residential Split System Long-Line Application Guideline.
† For buried line applications, refer to Residential Split System Buried-Line Application Guideline.
‡ Required for Low-Ambient Controller (full modulation feature) and MotorMaster Control only.
Fig. 10—Typical 24-v Circuit Conncetion using Carrier Model DF Thermostat with Single- or 2-Stage Furnace
A97638
G
R
Y/Y2
O/W2
CARRIER
DUAL FUEL
THERMOSTAT
MODEL DF
SINGLE-STAGE
FURNACE HEAT PUMP
G
Y
W
C
Y
R
O
W2
Y1/W2
C
B
L
S1
S2
R
C
FURNACE
COMPRESSOR
FAN
24 VAC HOT
24 VAC COM
N/A
RVS HEATING
RVS SENSING
OUTDOOR
SENSOR
CONNECTION
OUTDOOR
TEMPERATURE
SENSOR
W/W1
See note 7
RVS COOLING
A97539
G
R
Y/Y2
O/W2
CARRIER
DUAL FUEL
THERMOSTAT
MODEL DF
TWO-STAGE OR
VARIABLE SPEED
FURNACE
HEAT PUMP
G
C
Y
R
O
W2
Y1/W2
C
B
L
S1
S2
R
C
O
W2
Y1
FURNACE LO
COMPRESSOR
FAN
24 VAC HOT
24 VAC COM
FURNACE HI
RVS HEATING
RVS SENSING
OUTDOOR
SENSOR
CONNECTION OUTDOOR
TEMPERATURE
SENSOR
W/W1 W/W1
Y/Y2
See notes 7 and 8
RVS COOLING
6