Carrier 48XL - Manual (Page 12)

Table 2 - Maximum Gas Flow Capacity*
NOMINAL
IRON PIPE
SIZE (IN.)
INTERNAL
DIAMETER
(IN.)
LENGTH OF PIPE ft (m)t
10
(3.0)
20
(6.1)
30
(9.1)
40
(12.1)
50
(15.2)
60
(18.3)
70
(21.3)
80
(24.4)
90
(27.4)
100
(30.5)
125
(38.1)
150
(45.7)
175
(53.3)
200
(61.0)
1/2 .622 175 120 97 82 73 66 61 57 53 50 44 40 — —
3/4 .824 360 250 200 170 151 138 125 118 110 103 93 84 77 72
1 1.049 680 465 375 320 285 260 240 220 205 195 175 160 145 135
1-1/4 1.380 1400 950 770 600 580 530 490 460 430 400 360 325 300 280
1 -1/2 1.610 2100 1460 1180 990 900 810 750 690 650 620 550 500 460 430
*Capaoity of pipe in cu ft of gas per hr for gas pressure of 0.5 psig or iess. Pressure drop of 0.5-IN. W.C. (based on a 0.60 specific gravity gas). Refer to Tabie,
NFPA54/ANSI Z223.1.
t This iength inoiudes an ordinary number of fittings.
ROUTING POWER LEADS INTO UNIT
Use only copper wire between disconnect and unit. The high
voltage leads should be in a conduit until they enter the duct panel;
conduit termination at the duct panel must be watertight. Run the
high-voltage leads through the power entry knockout on the
power entry side panel. See Fig. 3 and 6 for location and size. For
single-phase units, connect leads to the black and yellow wires,
CONNECTING GROUND LEAD TO GROUND SCREW
Connect the ground lead to the chassis using the ground screw on
the control plate near the inducer switch (See Fig. 13).
ROUTING CONTROL POWER WIRES
For detailed instruction on the low voltage connections to the User
Interface (UI), refer to the UI installation guide.
Form a drip-loop with the control leads before routing them into
the unit. Route the low voltage control leads through grommeted,
low-voltage hole provided into unit (See Fig. 3 and 6). Connect
user interface leads to unit control power leads as shown in Fig. 14.
The unit transformer supplies 24-v power for complete system
including accessory electrical heater. Transformer is factory wired
for 230-v operation. If supply voltage is 208-v, rewire transformer
primary as described in Special Procedures for 208-v Operation
section.
The furnace board is fused by a board-mounted automotive fuse
placed in series with transformer SECl and R circuit. The C circuit
of transformer circuit is referenced to chassis ground through a
printed circuit run at SEC2 and gas valve grounding wire. Check to
be sure control board is mounted securely using both
factory-installed screws,
ACCESSORY INSTALLATION
A. Outdoor Air Thermistor (OAT)
^ CAUTION
EQUIPMENT OPERATION HAZARD
The installation of an outdoor temperature sensor using the
Infinity control board OAT terminals is required. Many
Infinity features (auto humidity control, comfort rollback,
ETC.) will be lost if the OAT is not connected.
For detailed mounting instructions for the OAT sensor,
please refer to TSTATXXSENOf-B installation instructions
(catalog no, 63TS-TA13): Procedures f through 3,
The OAT input is used to supply outdoor temperature data for
system level functions and for temperature display on User
Interface (UI). Using two wires of the field-supplied thermostat
wire cable, wire the ends of the two black OAT pigtails. Wire the
opposite ends of these two wires to the OAT provided with the UI,
There is no polarity to be observed,
NOTE: Mis-wiring OAT inputs will not cause damage to either
Infinity control or thermistor. If the thermistor is wired incorrectly,
no reading will appear at UI, Re-wire thermistor correctly for
normal operation,
B. Humidifier Connections
The furnace control board terminal marked HUM is provided for
low voltage (24-vac) control of a humidifier. No humidistat is
required as UI monitors indoor humidity.
When commanded to operate humidifier, the unit control will
energize the HUM output to turn humidifier on and de-energize
HUM output to turn humidifier off. Wire HUM and COM
terminals directly to humidifier as shown in Fig. 14,
C. Electronic Air Cleaner
Electronic Air Cleaner terminals are provided on the Infinity
Control Board (EAC-1 and EAC-2). While these terminals can be
used to power a 230V EAC, it is recommended that any EAC be
installed per the EAC installation instructions and connected
separately to a standard 113V or 230V outlet with an airflow
sensor to control operation of the EAC,
SPECIAL PROCEDURES FOR 208-V OPERATION
Be sure unit disconnect switch is open.
Disconnect the black primary lead from the transformer. See unit
wiring label (See Fig. 16 and 17).
Connect the black primary lead to the transformer terminal labeled
208-v,
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