Do not connect aluminum wire between disconnect switch
and furnace. Use only copper wire.
Make all electrical connections in accordance with the current
edition of the National Electrical Code (NEC) ANSI/NFPA
70-1993 and any local codes or ordinances that might apply. For
Canadian installations, all electrical connections must be made in
accordance with CSA C22.1 Canadian Electrical Code or authori-
ties having jurisdiction.
NOTE:
Proper polarity must be maintained for 115-v wiring. If
polarity is incorrect, the furnace control status LED will flash
rapidly and prevent heating operation.
The cabinet must have an uninterrupted or unbroken ground
according to NEC ANSI/NFPA 70-1993 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.
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.
11.) Connect terminal Y/Y2 as shown in Fig. 12 or 13 for proper
operation in cooling mode. Use AWG No. 18 color-coded, copper
thermostat wire only.
When the furnace is installed in the horizontal position with RH
discharge air, 24-v wire connections can be made easier by
removing the 2 control box mounting screws and letting the
control box turn so that the 24-v screw terminals are visible. Be
sure to reinstall the control box after the connections are made.
The 24-v circuit contains an automotive-type, 3-amp fuse located
on the 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 the fuse needs replacement.
ACCESSORIES
1. Electronic air cleaner (EAC)
A terminal block (EAC-1 [hot] and EAC-2 [neutral]) is
provided for EAC connection. (See Fig. 11.) 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.
Step 9—VENTING
Refer to the enclosed Installation Instructions, GAMA venting
table for Category I furnaces and QUIK•VENT™ table for 1- and
2-Stage Category I fan-assisted furnaces. In Canada, use venting
tables as found in CAN/CGA B149.1 or .2. The horizontal portion
of the venting system shall maintain a minimum of 1/4-in. upward
slope per linear ft (away from furnace), 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.
Table 4—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 54-1992.
Fig. 10—Typical Gas Pipe Arrangement
A89414
GAS
SUPPLY
MANUAL
SHUTOFF
VALVE
SEDIMENT
TRAP
UNION
Fig. 11—Control Center
A93348
1
2
3
4
5
6
7
8
9
PR2
L2
COM
PR1
L1
EAC-2
EAC-1
H
I-
C
O
O
L
HI-GAS
-HEAT
LO-GAS
-HEAT
PARK
3
FU1
SEC-1
SEC-2
1
1
2
3
4
5
6
7
8
9
10
11
12
MASTER SLAVE
TWIN
TEST
LED
G
R
Y/Y2
W/W1
COM
24 V
W2
1
ON
OFF
1
2
3
4
FURNACE AND
BLOWER OFF DELAY
SETUP SWITCHES
24-VOLT
THERMOSTAT
TERMINALS
EAC - ELECTRONIC
AIR CLEANER
(115-VAC 1 AMP MAX)
3-AMP
FUSE
LED -
DIAGNOSTIC
LIGHT
TWIN / TEST
TERMINAL
HUM -
HUMIDIFIER
(24-VAC 0.5
AMP MAX)
HUM
8