10
FIELD CONTROL WIRING — Install a Carrier-approved
accessory thermostat assembly according to installation in-
structions included with the accessory. Locate thermostat
assembly on a solid wall in the conditioned space to sense aver-
age temperature in accordance with thermostat installation
instructions.
NOTE: If using Carrier electronic thermostat, set thermostat
configuration for “non-heat pump operation.” The use of the O
terminal is not required to energize the reversing valve in this
family of products.
Route thermostat cable or equivalent single leads of colored
wire from subbase terminals to low-voltage connections on
unit (shown in Fig. 9) as described in Steps 1 through 4 below.
NOTE: For wire runs up to 15 m (50 ft), use no. 18 AWG
(American Wire Gage) insulated wire (35 C minimum). For
15 m to 23 m (51 to 75 ft), use no. 16 AWG insulated wire
(35 C minimum). For over 23 m (75 ft), use no. 14 AWG insu-
lated wire (35 C minimum). All wire larger than no. 18 AWG
cannot be directly connected to the thermostat and will require
a junction box and splice at the thermostat. See Table 3 for
American/European wire conversions.
1. If unit is mounted on roof curb and accessory thru-the-
curb service plate connection is used, route wire through
connection plate.
2. Pass control wires through the hole provided on unit (see
connection D in Connection Sizes table in Fig. 5).
3. Feed wire through the raceway built into the corner post
to the 24-v barrier located on the left side of the control
box. See Fig. 9. The raceway provides the UL (Under-
writers’ laboratories, U.S.A.) required clearance between
the high- and low-voltage wiring.
4. Connect thermostat wires to screw terminals of low-
voltage connector (see Fig. 10).
NOTE: If thru-the-bottom power connections are used refer to
the accessory installation instructions for information on power
wiring. Refer to Fig. 5 for drilling holes in basepan.
DEFROST BOARD — The defrost board timer cycle is set to
30 minutes. To change the cycle time, remove the wire from
defrost board connected to the 30 minute quick-connect. See
Fig. 11. Connect the wire to the 50 or 90 minute quick-
connects on the defrost board, depending on the desired defrost
time.
Table 3 — American/European Wire Conversions
LEGEND
HEAT ANTICIPATOR SETTINGS — For units with elec-
tric heat, set heat anticipator settings as shown in Table 4.
Table 4 — Heat Anticipator Settings
AMERICAN
EUROPEAN
Industry
Standard Size
American Conversion
(mm
2
)
Industry Standard
Size (mm
2
)
18 AWG
0.82
1.0
16 AWG
1.30
1.5
14 AWG
2.08
2.5
12 AWG
3.30
4.0
10 AWG
5.25
6.0
8 AWG
6.36
10.0
6 AWG
13.29
16.0
4 AWG
21.14
25.0
3 AWG
26.65
—
2 AWG
33.61
35.0
1 AWG
42.39
50.0
1/0 AWG
53.49
—
2/0 AWG
67.42
70.0
3/0 AWG
85.00
95.0
4/0 AWG
107.19
120.0
250 kcmil
126.64
150.0
300 kcmil
151.97
—
350 kcmil
177.90
185.0
400 kcmil
202.63
240.0
500 kcmil
253.29
300.0
600 kcmil
303.95
—
AWG —
American Wire Gage
kcmil —
Thousand Circular Mils
UNIT
UNIT VOLTAGE
400
Heater
kW
Configuration
1-Stage
2-Stage
Stage 1
Stage 1
Stage 2
50TFQ
9.6, 11.5, 19.3, 28.9
0.3
NA
NA
22.9, 34.7
0.6
0.3
0.3
SINGLE-POINT BOX
RACEWAY
TERMINAL
STRIP
EURO-STYLE
CONTROL BOX
DISCONNECT
SWITCH
(OPTIONAL)
LEGEND
Fig. 10 — Low-Voltage Connections With or
Without Economizer or Two-Position Damper
AHA —
Adjustable Heat Anticipator
Field Wiring
Factory Wiring
Fig. 9 — Typical Field Control Wiring Raceway
