Trane 4TWX7 Series Installer's Manual page 14

11.2 Low Voltage Hook-up Diagrams (cont.)
Thermostat
24 VAC HOT
FAN
24 VAC B/C
Common
SOV
COOL/HEAT
1st STAGE
COOL/HEAT
2nd STAGE
HEATING
2nd STAGE
EMERGENCY
HEAT
BK
WH/BLK
Units with pigtails require wirenuts for connections.
•
In systems with multiple stages of electric heat, jumper W1 and W2 together if comfort control has only one stage of heat.
•
** TEM6 only - When using a BK enabled comfort control, cut BK jumper and bypass Y1 and Y2 at the air handler. Connect BK from
comfort control to BK of the air handler
• TAM7 only - When using a BK enabled comfort control, cut BK jumper on the AFC and connect BK from comfort control to BK of
the air handler. T
Note: Refer to Indoor Unit Literature for proper configuration.
11.3 Defrost Control
Defrost controls have a selectable termination temperature. As shipped, defrost will terminate at 47°F. For a
higher termination temperature, cut Jumper J2 to achieve 70°F when at or below 30°F ambient. See Service
Facts shipped in the outdoor unit for more information.
Pin Identification (See Illustration at right)
1. TEST_COMMON (Shorting any of the other pins to this pin causes the function of the other pin to be
executed. Leaving this pin open results in the normal mode of operation.)
2. TST = Test (Shorting TEST_COMMON to this pin speeds up all defrost board timings.)
3. FRC_DFT = Forced Defrost (Short TEST_COMMON to this pin for two (2) seconds to initiate a forced
defrost. Remove the short after defrost initiates.)
Defrost Control Checkout
Normal operation requires:
•
LED on board flashing 1 time/second.
•
24V AC between R & B.
•
24V AC between Y & B with unit operating.
•
Defrost initiation when FRC_DFT pin is shorted to TEST_COMMON pin.
If a defrost control problem is suspected, refer to the service information in control box.
14
With TEM 6/8
Outdoor
Air Handler
Unit
R R R
G G
B
B
Blue
O
O O
Y1 Y1 Y1
Y2 Y2 Y2
W1
W
White
X2
W2
X2
Pink Black
BK
WH/BLK
AM7 DIP switches must be configured for "HP: 2-Stage/1 Compressor".
With TAM 7/9
Thermostat Air Handler
R R
24 VAC HOT
G G
FAN
B
24 VAC B/C
Common
Blue
O
O
SOV
COOL/HEAT
Y Y
1st STAGE l l
Y
O
COOL/HEAT
Y2 Y2
2nd STAGE
W1
HEATING
W
2nd STAGE
White
EMERGENCY W2
X2
HEAT
Pink
BK BK
WH/BLK WH/BLK
Outdoor
Unit
R
B
O
Y
O
Y2
X2
Black
18-BC109D1-1A-EN