Carrier 100/A Series Installation, Start-Up, Operating And Service And Maintenance Instructions page 36

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START-UP, ADJUSTMENT, AND SAFETY
CHECK
General
FIRE HAZARD
Failure to follow this warning could result in personal
iniury, death and/or property damage.
This furnace is equipped with manual reset limit switches in
the gas control area. The switches 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
switches. Correct inadequate combustion air supply
problem before resetting the switches.
CUT HAZARD
Failure to follow this caution may result in personal iniury.
Sheet metal parts may have sharp edges or burrs. Use care
and wear appropriate protective clothing, safety glasses and
gloves when handling parts and servicing furnaces.
1. Maintain 115-v wiring and ground. Improper polarity will
result in rapid flashing LED and no furnace operation.
2. Make thermostat wire connections at the 24-v terminal
block on the furnace control. Failure to make proper
connections will result in improper operation. (See Fig.
25 .)
3. Gas supply pressure to the furnace must be greater than
4.5-in. wc (0.16 psig ) but not exceed 14-in. wc (0.5
psig).
4. Check all manual-reset switches for continuity.
5. Install blower compartment door. Door must be in place to
operate furnace.
6. Replace outer door.
Start-Up Procedures
FIRE AND EXPLOSION HAZARD
Failure to follow this warning could cause personal injury,
death and/or property damage.
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.
1.
2.
3.
Purge gas lines after all connections have been made.
Check gas lines for leaks.
To Begin Component Self-Test:
Remove blower access door. Disconnect the thermostat R
lead from the furnace control board. Manually close the
blower door switch closed. Short (iumper) the COM-24v
terminal on control to the TEST/TWIN 3/16-inch quick
connect terminal on control until LED goes out
(approximately 2 sec). Gas valve and humidifier will not
be turned on. (See Fig. 24.)
ELECTRICALSHOCK HAZARD
Failure to follow this warning could result in personal
iniury, or death.
Blower access door switch opens l15-v power to control.
No component operation can occur unless switch is closed.
Caution must be taken when manually closing this switch
for service purposes.
NOTE: The furnace control allows all components, except the
gas valve, to be run for short period of time. This feature helps
diagnose a system problem in case of a component failure.
Component test feature will not operate if any thermostat signal is
present at the control.
Component test sequence is as follows:
Refer to service label attached to furnace or see Fig. 55.
a. LED will display previous status code 4 times.
b. Inducer motor starts and continues to run until Step f of
component test sequence.
c. Hot surface igniter is energized for 15 sec., then off.
d. Blower motor operates on HEAT speed for 10 sec.
e. Blower motor operates on COOL speed for 10 sec.
f. Inducer motor stops.
g. Reconnect R lead to furnace control board, release blower
door switch and re-install blower door.
4. Operate furnace per instruction on door.
5. Verify furnace shut down by lowering thermostat setting
below room temperature.
6. Verify furnace restarts by raising thermostat setting above
room temperature.
Adiustments
FIRE HAZARD
Failure to follow this warning could result in iniury, death
and/or property damage.
DO NOT bottom out gas valve regulator adjusting screw.
This can result in unregulated manifold pressure and result in
excess overfire and heat exchanger failures.
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in reduced furnace
life.
DO NOT redrill orifices. Improper drilling (burrs,
out-of-round holes, etc.) can cause excessive burner noise
and misdirection of burner flames. This can result in flame
impingement of heat exchangers, causing failures. (See Fig.
53.)
Furnace gas input rate on rating plate is for installations at
altitudes up to 2000 ft. (610 M). Furnace input rate must be
within +/-2 percent of furnace rating plate input. For altitudes
above 5500 ft. (1676 M), a field-supplied high altitude pressure
switch is required.
1. Determine the correct gas input rate.
In the U.S.A.:
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