The cabinet MUST have an uninterrupted or unbroken ground
according to NEC ANSI/NFPA 70-1999 and Canadian Elec-
trical 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. Failure to follow this
warning could result in electrical shock, fire, or death.
24-V WIRING
Make field 24-v connections at the 24-v terminal strip. (See Fig.
14.) Connect terminal Y as shown in Fig. 15 for proper operation
in cooling mode. Use AWG No. 18 color-coded wire only.
The 24-v circuit contains an automotive-type, 3-amp fuse located
on the main control board. Any direct shorts during installation,
service, or maintenance could cause this fuse to blow. If fuse
replacement is required, use ONLY a 3-amp fuse of identical size.
ACCESSORIES
1. Electronic air cleaner (EAC)
Two quick-connect terminals, marked EAC-1 and EAC-2, are
provided for EAC connection. (See Fig. 14.) These terminals
are energized with 115v (1.0-amp maximum) during blower
motor operation.
2. Humidifier (HUM)
Quick-connect terminal (HUM) and screw terminal (C
OM
-
24V) are provided for 24-v humidifier connection. The termi-
nals are energized with 24V (0.5-amp maximum) after inducer
motor prepurge period.
DO NOT connect furnace control HUM terminal to HUM
(humidifier) terminal on Thermidistat™, Zone Controller, or
similar device. See Thermidistat, Zone Controller, thermostat,
or controller manufacturer’s instructions for proper connec-
tion. A failure to follow this warning could result in fire.
NOTE:
A field-supplied, 115-v controlled relay connected to
EAC terminals may be added if humidifier operation is desired
during blower operation.
Step 11—Venting
Refer to the national or local installation code such as NFGC in the
United States, or the NSCNGPIC in Canada for proper vent sizing
and installation requirements. Use the enclosed Installation In-
structions (Single-Stage Vent Tables for Category I Fan-Assisted
Furnaces) for a quick, easy reference.
After fully assembling the vent connector to the furnace flue collar,
securely fasten the vent connector to the collar with two field-
supplied, corrosion-resistant, sheet metal screws located 180° 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. 12—Downflow Filter Arrangement
A88486
RETURN-AIR
PLENUM
,,,,
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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
pressure drop of 0.5-in. wc (based on a 0.60 specific gravity gas). Ref: Table
10-2 NFPA 54/ANSI Z223.1-1999.
Fig. 13—Typical Gas Pipe Arrangement
A89414
GAS
SUPPLY
MANUAL
SHUTOFF
VALVE
(REQUIRED)
SEDIMENT
TRAP
UNION
11
