Carrier bryant 830CA, User Manual

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830CA: Installation, Start–Up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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2. Determine the correct outlet gas pressure adjustment.
a. Obtain average yearly gas heat value (at installed altitude) from
local gas supplier.
b. Obtain average yearly gas specific gravity from local gas
supplier.
c. Find closest natural gas heat value and specific gravity in
Table 14 through Table 17 .
d. Follow heat value and specific gravity lines to point of
intersection to find outlet pressure setting for proper operation.
3. Check Inlet Gas Pressure
The inlet gas pressure must be checked with the furnace operating. This
is necessary to make sure the inlet gas pressure does not fall below the
minimum pressure of 4.5 in. w.c.
a. Make sure the gas supply is turned off to the furnace and at the
electric switch on the gas valve
b. Loosen set screw on outlet tower pressure tap no more than one
full turn with a 3/32−in. hex wrench or remove the 1/8−in. NPT
plug from the inlet pressure tap on the gas valve.
c. Connect a manometer to the inlet pressure tap on gas valve.
d. Turn on furnace power supply.
e. Turn gas supply manual shutoff valve to ON position.
f. Turn furnace gas valve switch to ON position.
g. Jumper R and W thermostat connections at the furnace control
board.
h. When main burners ignite, confirm inlet gas pressure is between
4.5 in. W.C. (1125 Pa) and 13.6 in. W.C. (3388 Pa).
i. Remove jumper across thermostat connections to terminate call
for heat. Wait until the blower off delay is completed.
j. Turn furnace gas valve electric switch to OFF position.
k. Turn gas supply manual shutoff valve to OFF position.
l. Turn off furnace power supply.
m.Remove manometer from the inlet pressure tap of the gas valve.
n. Tighten set screw on inlet tower pressure tap with 3/32−in. hex
wrench, or if 1/8−in. NPT plug was removed, apply pipe dope
sparingly to end of plug and reinstall in the gas valve
4. Adjust gas valve outlet pressure determined in Step 2 to obtain
correct input rate.
a. Turn gas valve ON/OFF switch to OFF.
b. Loosen set screw on inlet tower pressure tap no more than one
full turn with a 3/32 in. hex wrench, see Fig. 21
c. Connect a water column manometer or similar device to pressure
tap on the gas valve.
d. Turn gas valve ON/OFF switch to ON.
e. Manually close blower door switch.
f. Set thermostat to call for heat.
g. Remove regulator seal cap and turn regulator adjusting screw
counterclockwise (out) to decrease input rate of clockwise (in) to
increase input rate.
h. Install regulator seal cap.
i. Leave manometer or similar device connected and proceed to
next step.
NOTE: If orifice hole appears damaged or it is suspected to have been
redrilled, check orifice hole with a numbered drill bit of correct size.
Never redrill an orifice. A burr-free and properly sized orifice hole is
essential for proper flame characteristics.
5. Verify natural gas input rate by clocking meter.
NOTE: Gas valve regulator adjustment cap must be in place for proper
input to be clocked.
a. Turn off all other gas appliances and pilots served by the meter.
b. Run furnace for 3 minutes in heating operation.
c. Measure time (in seconds) for gas meter to complete 1 revolution
and note reading. The 2 or 5 cubic feet dial provides a more
accurate measurement of gas flow.
d. Refer to Table 13 for cubic ft. of gas per hr.
e. Multiply gas rate (cu ft./hr) by heating value (Btuh/cu ft) to
obtain input.
If clocked rate does not match required input from Step 1, increase gas
valve outlet pressure to increase input or decrease gas valve outlet
pressure to decrease input. Repeat steps b through e until correct input is
achieved. Reinstall regulator seal cap on gas valve.
6. Set temperature rise. The furnace must operate within the
temperature rise ranges specified on the furnace rating plate. Do not
exceed temperature rise range specified on unit rating plate.
Determine the temperature rise as follows:
NOTE: Blower access door must be installed when taking temperature
rise reading. Leaving blower access door off will result in incorrect
temperature measurements. When setup switch SW1-4 is ON, operation
will be near the high end of the rise range for improved comfort. Furnace
must operate within the temperature rise range specified on the furnace
rating plate.
a. Place thermometers in return and supply ducts as close to furnace
as possible. Be sure thermometers do not see radiant heat from
heat exchangers. Radiant heat affects temperature rise readings.
This practice is particularly important with straight-run ducts.
b. When thermometer readings stabilize, subtract return-air
temperature from supply-air temperature to determine air
temperature rise.
NOTE: If the temperature rise is outside this range, first check:
(1.) Gas input for heating operation.
(2.) Return and supply ducts for excessive restrictions causing
static pressures greater than the maximum heating static
listed on the rating plate.
(3.) Ensure Comfort/Efficiency SW1-4 on furnace control is in
OFF = Efficiency position when a bypass humidifier is
used, see Table 10 .
(4.) Make sure proper model plug is installed.
c. Adjust air temperature rise by adjusting blower speed. Increase
blower speed to reduce temperature rise. Decrease blower speed
to increase temperature rise.
d. Turn thermostat down below room temperature and remove
blower access door.
e. To increase heating airflow, set Comfort/Efficiency SW1-4 on
furnace control to OFF = Efficiency.
f. Repeat steps a through e.
g. When correct input rate and temperature rise is achieved, turn
gas valve ON/OFF switch to OFF.
h. Remove manometer or similar device from gas valve.
i. Tighten set screw on outlet tower pressure tap with 3/32 in. hex
wrench.
WARNING
!
FIRE HAZARD
Failure to follow this warning could result in personal injury, death,
and/or property damage.
Inlet pressure tap set screw must be tightened and 1/8-in. NPT pipe
plug must be installed to prevent gas leaks.
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury or death.
Disconnect 115-v electrical power and install lockout tag before
changing speed tap.