Operating instructions

WARNING: The cabinet must have an uninterrupted or
unbroken ground according to NEC ANSI/NFPA 70-
1999 and Canadian Electrical Code CSA C22.1 or local
codes to minimize personal injury if an electrical fault
should occur. This may consist of electrical wire or
conduit approved for electrical ground when installed in
accordance with existing electrical codes. Do not use gas
piping as an electrical ground.
B. 24-v Wiring
Refer to ESD Precautions Procedure before proceeding with 24-v
connections.
Make field 24-v connections at the 24-v terminal block. (See Fig.
14.) Connect terminal Y/Y2 as shown in Fig. 15 or 16 for proper
operation in cooling mode. Use AWG No. 18 color-coded, copper
thermostat wire only.
When furnace is installed in horizontal position with RH discharge
air, 24-v wire connections can be made easier by removing the 2
control box mounting screws and letting control box turn so that
24-v screw terminals are visible. Be sure to reinstall control box
after connections are made.
The 24-v circuit contains an automotive-type, 3-amp fuse located
on main control. Any 24-v electrical shorts during installation,
service, or maintenance could cause this fuse to blow. If fuse
replacement is required, use ONLY a 3-amp fuse. The control will
flash code 24 when fuse needs replacement.
C. Accessories
1. Electronic air cleaner (EAC)
A terminal block (EAC-1 [hot] and EAC-2 [neutral]) is
provided for EAC connection. (See Fig. 14.) The terminals
are energized with 115v, 1-amp maximum during blower
motor operation.
2. Humidifier (HUM)
Screw terminals (HUM-1 and COM) are provided for 24-v
humidifier connection. The terminals are energized with
24v, 0.5-amp maximum when the gas valve is energized.
X. VENTING
Refer to the enclosed Installation Instructions, (Vent Tables For 1-
and 2-Stage Category I Fan-Assisted Furnaces) for quick, easy
reference, and national or local installation code such as National
Fuel Gas Code NFPA 54-1999/ANSI Z223.1-1999 in the United
States, or the National Standard of Canada Natural and Propane
Installation Codes CAN/CGA-B149.1- and .2-M95 in Canada, for
proper vent sizing and installation requirements.
After fully assembling the vent connector to the furnace flue collar,
securely fasten the vent connector to the collar with 2 field-
supplied, corrosion-resistant, sheet metal screws located 180
degrees apart and midway up the collar.
The horizontal portion of the venting system shall maintain a
minimum of 1/4-in. upward slope per linear ft, and it shall be
rigidly supported every 5 ft or less with hangers or straps to ensure
that there will be no movement after installation.
Fig. 11—Horizontal Installation on Blocks
A95235
→TABLE 4—FILTER RETAINER (IN.)
FURNACE CASING WIDTH FILTERS D
14-3/16 (2) 16 X 20 X 1 15-3/8
17-1/2 (2) 16 X 20 X 1 14-3/4
21 (2) 16 X 20 X 1 13-3/4
24-1/2 (2) 16 X 20 X 1 12-1/2
Fig. 12—Horizontal Filter Arrangement
A82173
FIELD-SUPPLIED
FILTER RETAINERS
AIRFLOW
D
12
″
4
″
Fig. 13—Downflow Filter Arrangement
A88486
RETURN-AIR
PLENUM
AIRFLOW
ACCESS DOOR
INSTALLATION
POSITION
OF FILTERS
TABLE 5—MAXIMUM CAPACITY OF PIPE*
NOMINAL
IRON PIPE
SIZE (IN.)
INTERNAL
DIAMETER
(IN.)
LENGTH OF PIPE (FT)
10 20 30 40 50
1/2 0.622 175 120 97 82 73
3/4 0.824 360 250 200 170 151
1 1.049 680 465 375 320 285
1-1/4 1.380 1400 950 770 660 580
1-1/2 1.610 2100 1460 1180 990 900
* Cubic ft of gas per hr for gas pressures of 0.5 psig (14-in. wc) or less, and a
supply line pressure drop of 0.5-in. wc (based on a 0.60 specific gravity gas).
Ref: Table 10-2, NFPA 54-1996.
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