Carrier 59SC2C Series Installation, Start-Up, Operating And Service And Maintenance Instructions page 66

i. Remove jumper R to W.
2. Verify natural gas input rate by clocking meter.
NOTE: Contact your HVAC distributor or gas supplier for metric
gas meter Tables, if required.
a. Turn off all other gas appliances and pilots served by the
meter.
b. Jumper R to W.
c. Run furnace for 3 minutes.
d. Measure time (in sec) for gas meter to complete one revolu-
tion and note reading. The 2 or 5 cubic feet dial provides
a more accurate measurement of gas flow.
e. Refer to Table 20 for cubic ft. of gas per hr.
f. Multiply gas rate cu ft./hr by heating value (Btuh/cu ft.) to
obtain input rate.
g. If clocked rate does not match required input from Step 1,
increase manifold pressure to increase input or decrease
manifold pressure to decrease input. Repeat steps b through
e of Step 1 until correct heat input is achieved. Re- -install
regulator seal cap on gas valve.
3. Restore furnace to normal operating condition.
a. Turn gas valve ON/OFF switch to OFF.
b. Remove water column manometer or similar device from
manifold pressure tap.
c. Replace manifold pressure tap plug to gas valve.
d. Turn gas valve ON/OFF switch to ON.
e. Check for gas leaks and verity furnace operation.
WARNING
!
FIRE HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Reinstall manifold pressure tap plug in gas valve to prevent
gas leak.
Adjust Temperature Rise
NOTE: Blower door must be installed when taking temperature
rise reading. Leaving blower door off will result in incorrect
temperature measurements, due to possible changes in duct static
pressure and airflow.
CAUTION
!
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in:
S Overheating the heat exchangers or condensing flue gases
in heat exchanger areas not designed for condensate.
S Shortened furnace life.
S Component damage.
Temperature rise must be within limits specified on furnace
rating plate. Recommended operation is at midpoint of rise
range or slightly above.
Jumper R to W to check gas- -heat temperature rise. Do not exceed
temperature rise ranges specified on unit rating plate.
This furnace must operate within the temperature rise ranges
specified on the furnace rating plate. Determine the air temperature
as follows:
1. Place duct thermometers in return and supply ducts as close
to furnace as possible. Be sure thermometers do not "see"
heat exchangers so that radiant heat does not affect
thermometer readings. This is particularly important with
straight run ducts.
2. When thermometer readings stabilize, subtract return- -air
temperature from supply- -air temperature to determine
temperature rise.
If the temperature rise is outside this range, check the following:
1. Gas input rate.
2. Derate for altitude, if applicable.
3. Return and supply ducts for excessive restrictions causing
static pressures greater than 0.50- -in. W.C. (125 Pa)
4. Adjust temperature rise by adjusting blower speed.
S Increase blower speed to reduce temperature rise.
S Decrease blower speed to increase temperature rise.
WARNING
!
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal injury
or death.
Disconnect 115vac electrical power before changing speed tap.
(Read following caution before changing taps).
CAUTION
!
UNIT DAMAGE HAZARD
To avoid operating outside the rise range and avoid
component damage:
Refer to the Air Delivery Tables to determine which airflows
and settings are allowed for proper heating airflow. DO NOT
use the highlighted settings for Heating airflow. The
highlighted settings are to be used for Cooling and
Continuous Fan ONLY.
Change these settings as required to maintain proper temperature
rise for Heating and Cooling as described above. To change blower
motor speed selections for heating mode, remove blower motor
lead from control HEAT terminal. See Fig. 38. Select desired
blower motor speed lead from one of the other motor leads and
relocate it/them to HEAT (heating blower tap) terminal(s).
Reconnect original lead on SPARE terminal.
Adjust Blower Off Delay (Heat Mode)
If desired, the main blower off time delay period may be
lengthened or shortened when operating in the heating mode to
provide greater comfort. For position and location of jumpers on
control center, see Fig. 38 and Fig. 70.
The blower off delay has four adjustable settings from 90 sec to
180 sec. See Table 18. To change the blower off delay setting,
move the jumper from one set of pins on the control to the pins
used for the desired blower off delay. Factory blower off delay
setting is 120 sec.
Table 18 – Blower Off Delay Jumper Positions
PINS 1 AND 2
Time (in sec.) 90
66
2 AND 3 3 AND 4 4 AND 5
120 150 180