-- 48 --
3. Use wire ties to secure heat tape in place. Wire ties can be
positioned in notches of condensate trap sides.
4. Wrap field drain pipe with remaining heat tape,
approximately 1 wrap per ft.
5. When using field-supplied heat tape, follow heat tape
manufacturer’s instructions for all other installation
guidelines.
START-UP, ADJUSTMENT AND SAFETY
CHECK
Step 1 -- General
1. Furnace must have a 115-v power supply properly
connected and grounded. Proper polarity must be
maintained for correct operation.
NOTE
:
Proper polarity and proper grounding must be
maintained for 115-v wiring. If polarity is incorrect, control
center LED status indicator light will flash rapidly and furnace
will not operate.
2. Thermostat wire connections at terminals R, W, G, and Y
must be made at 24-v terminal block on furnace
control center.
3. Natural gas service pressure must not exceed 0.5 psig
(14-in. wc), but must be no less than 0.16 psig
(4.5-in. wc).
4. Blower access panel must be in place to complete 115-v
electrical circuit to furnace.
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent
unit operation.
These furnaces are equipped with a manual reset limit switch
in burner box. This switch will open and shut power to gas
valve if an overheat condition (flame rollout) occurs in
burner enclosure. Correct inadequate combustion-air supply
or improper venting condition and reset switch. DO NOT
jumper this switch.
CAUTION
!
Before operating furnace, check flame rollout manual reset
switch for continuity. If necessary, press button to reset switch.
CONDENSATE TRAP
WIRE TIE(S)
HEAT TAPE
(3 WRAPS MINIMUM)
A93036
Fig. 45 --
Condensate Trap Heat Tape
Step 2 -- Prime Condensate Trap with Water
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent
unit operation.
Condensate trap must be PRIMED or proper draining may
not occur. The condensate trap has 2 internal chambers
which can ONLY be primed by pouring water into the
inducer drain side of condensate trap.
CAUTION
!
1. Remove upper inducer housing drain connection cap.
(See Fig. 46.)
2. Connect field-supplied 1/2-in. (13 mm) ID tube to upper
inducer housing drain connection.
3. Insert field-supplied funnel into tube.
4. Pour 1 quart of water into funnel/tube. Water should run
through inducer housing, overfill condensate trap, and
flow into open field drain. (See Fig. 47.)
5. Remove funnel and tube from inducer housing and replace
drain connection cap and clamp.
Step 3 -- Purge Gas Lines
FIRE AND EXPLOSION HAZARD
Failure to follow this warning could result in a fire, explosion,
personal injury, or death.
Never purge a gas line into a combustion chamber. Never test
for gas leaks with an open flame. Use a commercially
available soap solution made specifically for the detection of
leaks to check all connections.
!
WARNING
If not previously done, purge lines after all connections have been
made and check for leaks.
Step 4 -- Sequence of Operation
FURNACE MAY NOT OPERATE
Failure to follow this caution may result in furnace operation
stopping and water pipes freezing during cold weather.
Furnace control must be grounded for proper operation, or
control will lock out. Control is grounded through
green/yellow wire routed to gas valve and burner box screw.
CAUTION
!
Using schematic diagram, follow sequence of operation through
different modes. (See Fig. 33.) Read and follow wiring diagram
carefully.
NOTE
: If a power interruption occurs during a call for heat (W),
the control will start a 90-second blower-only ON period two
seconds after power is restored, if the thermostat is still calling
for gas heating. The red LED light will flash code 12 during the
90-second period, after which the LED will be ON continuous, as
long as no faults are detected. After the 90-second period, the
furnace will respond to the thermostat normally.
The blower door must be installed for power to be conducted
through the blower door interlock switch ILK to the furnace
control CPU, transformer TRAN, inducer motor IDM, blower
motor BLWM, hot-surface igniter HSI, and gas valve GV.
58MCB
