Table of Contents
Advertisement
BLK
WHT
GND
115-VOLT FUSED
DISCONNECT
SWITCH
(WHEN REQUIRED)
→ Fig. 10—Heating and Cooling Application Wiring Diagram 2-Stage Thermostat and Condensing Unit
Screw terminals (HUM and C
humidifier connection. The terminals are energized with
24v, 0.5-amp maximum when the gas valve is energized.
VII. VENTING
→
Refer to National or Local Installation Code such as; National Fuel
Gas Code NFPA No. 54-1996/Z223.1-1996, or the Canadian
Installation Code, CAN B149.1- and .2-M95, for proper vent
sizing and installation requirements. Use enclosed Venting Tables
for Category I Fan-Assisted Furnaces for quick, easy reference.
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.
Before installing furnace in Canada, refer to current edition of
NSCNGPIC. Contact Standards Department of Canadian Gas
Association, 55 Scarsdale Road, Don Mills, Ontario, Canada M3B
2R3.
VIII. START-UP, ADJUSTMENT, AND SAFETY CHECK
A. General
The furnace must have a 115-v power supply properly connected
and grounded. Correct polarity must be maintained to enable gas
heating operation.
The gas service pressure must not exceed 0.5 psig (14-in. wc), and
no less than 0.16 psig (4.5-in. wc).
Thermostat wire connections at R and W/W1 are the minimum
required for gas heating operation. W2 must be connected for
2-stage heating thermostats. C
cooling, heat pumps, and some clock thermostats. These must be
made at the 24-v terminal block on the control. (See Fig. 11.)
This furnace can be installed with either a single-stage heating or
a 2-stage heating thermostat.
For single-stage thermostats, connect thermostat W to W/W1 at
furnace control terminal block. (See Fig. 9.) For single-stage
thermostats, the control will determine, based on length of previ-
ous heating on and off cycles, when to operate in low- and
high-gas heat for optimum comfort. Setup switch-2 (SW-2) must
be in the factory-shipped OFF position. See Fig. 12 and Tables 6
and 7 for setup switch information.
2-STAGE THERMOSTAT TERMINALS
SEVEN
WIRE
THREE-WIRE
HEATING-
ONLY
W2
BLK
COM
WHT
W/W1
Y/Y2
JUNCTION
BOX
R
CONTROL
G
BOX
24-VOLT
TERMINAL
BLOCK
FURNACE
) are provided for 24-v
OM
, Y/Y2, and G are required for
OM
W2
W1
Y2
R
G
Y1
C
NOTES: 1. Connect Y-terminal as shown for proper operation.
2. Some thermostats require a "C" terminal connection as shown.
3. If any of the original wire, as supplied, must be replaced,
use same type or equivalent wire.
If a 2-stage heating thermostat is to be used, move SW-2 to ON
position at end of furnace installation. This overrides built-in
control process for selecting high and low fire and allows the
2-stage thermostat to select gas heating modes. The W2 from
thermostat must be connected to W2 on control terminal block.
(See Fig. 10.)
CAUTION: This furnace is equipped with a manual
reset limit switch in the gas control area. The switch will
open and shut off power to the gas valve if a flame rollout
or overheating condition occurs in the gas control area.
DO NOT bypass the switch. Correct inadequate
combustion-air supply, component failure, or restricted
flue gas passageway before resetting the switch.
Before operating furnace, check each manual reset switch for
continuity. If necessary, press and release button to reset switch.
TABLE 7—BLOWER OFF DELAY SETUP
DESIRED HEATING
MODE BLOWER OFF
DELAY (SEC)
B. Sequence of Operation
Using schematic diagram in Fig. 13, follow the sequence of
operation through the different modes. Read and follow diagram
very carefully.
NOTE: If power interruption occurs during "call for heat" (W/W1
or W/W1 and W2) and if the thermostat is still calling for gas
heating, the control will start a 90-sec blower only on period 2 sec
after power is restored. The red LED will flash code 12 during
90-sec period, after which the LED will be on continuously as long
as no faults are detected. After 90-sec period, furnace will respond
to the thermostat normally.
—9—
FIELD 24-VOLT WIRING
FIELD 115-, 208/230-, 460-VOLT WIRING
FACTORY 24-VOLT WIRING
FACTORY 115-VOLT WIRING
FIELD-SUPPLIED
FUSED DISCONNECT
C
Y1
Y2
GND
2-SPEED
CONDENSING
UNIT
SWITCH (SW) POSITION
SETUP SWITCH
SW-3
90
OFF
135
OFF
180
ON
225
ON
208/230- OR
460-VOLT
THREE
PHASE
208/230-
VOLT
SINGLE
PHASE
A97444
SW-4
OFF
ON
OFF
ON
Advertisement
Table of Contents
