Sequence Of Operation - Carrier 140/E Series Installation, Start-Up, Operating And Service And Maintenance Instructions

b. Insert the twisted wire end of brush into end of spring
cable, and crimp tight with crimping tool or crimp by
striking with ball- -peen hammer. TIGHTNESS IS
VERY IMPORTANT.
NOTE: The materials needed in item 9 can usually be purchased
at local hardware stores.
(1.) Attach variable- -speed, reversible drill to the end
of spring cable (end opposite brush).
(2.) Insert brush end of cable into the outlet opening
of cell and slowly rotate with drill. DO NOT
force cable. Gradually insert cable into upper pass
of cell. (See Fig. 62.)
(3.) Work cable in and out of cell 3 or 4 times to ob-
tain sufficient cleaning. DO NOT pull cable with
great force. Reverse drill and gradually work
cable out.
(4.) Insert brush end of cable in burner inlet opening
of cell, and proceed to clean 2 lower passes of
cell in same manner as upper pass.
(5.) Repeat foregoing procedures until each cell in
furnace has been cleaned.
(6.) Using vacuum cleaner, remove residue from each
cell.
(7.) Using vacuum cleaner with soft brush attachment,
clean burner assembly.
(8.) Clean flame sensor with fine steel wool.
(9.) Install NOx baffles (if removed).
Fig. 62 - - Cleaning Heat Exchanger Cell
(10.) Reinstall burner assembly. Center burners in cell
openings.
10. Remove old sealant from cell panel and collector box
flange.
11. Spray releasing agent on the heat exchanger cell panel
where collector box assembly contacts cell panel.
NOTE: A releasing agent such as cooking spray or equivalent
(must not contain corn or canola oil, aromatic or halogenated
hydrocarbons or inadequate seal may occur) and RTV sealant
(G.E. 162, 6702, or Dow- -Corning 738) are needed before
starting installation. DO NOT substitute any other type of RTV
sealant. G.E. 162 (P771- -9003) is available through RCD in 3- -oz
tubes.
12. Apply new sealant to flange of collector box and attach to
cell panel using existing screws, making sure all screws
are secure.
13. Reconnect wires to the following components (Use con-
nection diagram on wiring label, if wires were not marked
for reconnection locations.):
a. Draft safeguard switch.
b. Inducer motor.
c. Pressure switches.
d. Limit overtemperature switch.
e. Gas valve.
f. Hot surface igniter.
g. Flame- -sensing electrode.
h. Flame rollout switches.
14. Reinstall internal vent pipe, if applicable.
15. Reinstall vent connector on furnace vent elbow. Securely
fasten vent connector to vent elbow with 2 field- -supplied,
corrosion- -resistant, sheet metal screws located 180_ apart.
16. Replace blower access door only if it was removed.
17. Set thermostat above room temperature and check furnace
for proper operation.
18. Verify blower airflow and speed changes between heating
and cooling.
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage. Never use a match or
other open flame to check for gas leaks. Use a
soap- -and- -water solution.
19. Check for gas leaks.

Sequence of Operation

NOTE: Furnace control must be grounded for proper operation
or else control will lock out. Control is grounded through
green/yellow wire routed to gas valve and burner box screw.
Using the schematic diagram in Fig. 59, follow the sequence of
operation through the different modes. Read and follow the
wiring diagram very carefully.
NOTE: If a power interruption occurs during a call for heat
(W/W1 or W/W1- -and- -W2), 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 amber 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.
A91252 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.
1. Two- -Stage Heating (Adaptive Mode) with Single- -Stage
Thermostat
See Fig. 28 - - 35 for thermostat connections
NOTE: The low- -heat only switch SW1- -2 selects either the
low- -heat only operation mode when ON, (see item 2. below) or
the adaptive heating mode when OFF in response to a call for
heat. (See Table 8.) When the W2 thermostat terminal is
energized it will always cause high- -heat operation when the
R- -to- -W circuit is closed, regardless of the setting of the low- -heat
only switch. This furnace can operate as a two- -stage furnace with
a single- -stage thermostat because the furnace control CPU
includes a programmed adaptive sequence of controlled
operation, which selects low- -heat or high- -heat operation. This
selection is based upon the stored history of the length of
previous gas- -heating periods of the single- -stage thermostat.
52
WARNING