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Table 7—Air Delivery (Cfm) at Indicated Temperature Rise and Rated Heating Input
HEATING
INPUT
(BTUH)
20
INPUT
40,000
1500
60,000
2250
90,000
—
115,000
—
130,000
—
NOTE: Dashed areas do not fall within the approved temperature rise range of the unit.
HEATING SEQUENCE OF OPERATION—See Fig. 20-22 and
unit wiring label.
On a call for heating, terminal "W" of the thermostat is energized,
starting the induced-draft motor. When the hall-effect sensor on
the induced-draft motor senses that it has reached the required
speed, the burner sequence begins. This function is performed by
the integrated gas control (IGC). The evaporator fan motor is
energized 45 seconds after flame is established. When the thermo-
stat is satisfied and "W" is de-energized, the burners stop firing and
the evaporator fan motor shuts off after a 45-second time-off delay.
An LED (light-emitting diode) indicator is provided on the control
board to monitor operation. The control board is located by
removing the burner access panel. During normal operation, the
LED is continuously on. See Table 8 for error codes.
Table 8 LED Indications
ERROR CODE
Normal Operation
Hardware Failure
Fan On/Off Delay Modified
Limit Switch Fault
Flame Sense Fault
Four Consecutive Limit Switch Faults
Ignition Lockout Fault
Induced-Draft Motor Fault
Rollout Switch Fault
Internal Control Fault
Internal Software Fault
NOTES:
1.There is a 3-second pause between error code displays.
2. If more than one error code exists, all applicable error codes will be
displayed in numerical sequence.
3. This chart is on the wiring diagram located inside the burner access
panel.
LIMIT SWITCHES—Normally closed limit switch (LS) com-
pletes the control circuit through the thermostat R circuit. Should
the leaving-air temperature rise above the maximum allowable
temperature, the limit switch opens and the R control circuit
"breaks". Any interruption in the R control circuit instantly closes
the gas valve and stops gas flow to the burners and pilot. The
blower motor continues to run until LS resets.
When the air temperature at the limit switch drops to the
low-temperature setting of the limit switch, the switch closes and
completes the R control circuit. The electric spark ignition system
cycles and the unit returns to normal heating operation. When this
fault occurs, the IGC LED will display FAULT CODE 2.
AUXILIARY LIMIT SWITCH (ROLLOUT)—The function of
the switch is to close the main gas valve in the event of flame
rollout. The switch is located above the main burners. When the
temperature at the auxiliary switch reaches the maximum allow-
able temperature, the R control circuit trips, closing the gas valve
and stopping gas flow to the burners. The indoor (evaporator) fan
motor (IFM) and induced draft motor continue to run until switch
is reset. The IGC LED will display FAULT CODE 7.
25
30
35
1200
1000
857
1800
1500
1286
2700
2250
1929
—
—
2464
—
—
—
LED INDICATION
On
Off
1 Flash
2 Flashes
3 Flashes
4 Flashes
5 Flashes
6 Flashes
7 Flashes
8 Flashes
9 Flashes
TEMPERATURE RISE °F
40
45
50
750
667
600
1125
1000
900
1688
1500
1350
2156
1917
1725
2438
2167
1950
START UP COOLING SECTION AND MAKE ADJUST-
MENTS
Complete the required procedures given in the Pre-Start-Up
section on previous pages before starting the unit.
Do not jumper any safety devices when operating the unit.
Do not operate the compressor when the outdoor temperature
is below 40° F (unless accessory low-ambient kit is installed).
Do not rapid-cycle the compressor. Allow 5 minutes between
"on" cycles to prevent compressor damage.
CHECKING COOLING CONTROL OPERATION — Start and
check the unit for proper cooling control operation as follows:
1. Place room thermostat SYSTEM switch in OFF position.
Observe that blower motor starts when FAN switch is placed
in ON position and shuts down when FAN switch is placed in
AUTO position.
2. Place SYSTEM switch in COOL position and FAN switch in
AUTO position. Set cooling control below room temperature.
Observe that compressor, condenser fan, and evaporator
blower motors start. Observe that cooling cycle shuts down
when control setting is satisfied. The evaporator fan will
continue to run for 30 seconds.
3. When using an auto-changeover room thermostat, place both
SYSTEM and FAN switches in AUTO positions. Observe that
unit operates in Heating mode when temperature control is set
to "call for heating" (above room temperature) and operates in
Cooling mode when temperature control is set to "call for
cooling" (below room temperature).
IMPORTANT: Three-phase,
direction-oriented. These units must be checked to ensure proper
compressor 3-phase power lead orientation. If not corrected within
5 minutes, the internal protector will shut off the compressor. The
3-phase power leads to the unit must be reversed to correct
rotation. When turning backwards, scroll compressors emit el-
evated noise levels, and the difference between compressor suction
and discharge pressures may be dramatically lower than normal.
CHECKING AND ADJUSTING REFRIGERANT CHARGE
— The refrigerant system is fully charged with R-410A (Puron)
refrigerant, and is tested and factory sealed.
NOTE: Adjustment of the refrigerant charge is not required
unless the unit is suspected of not having the proper R-410A
charge. The charging label and the tables shown refer to system
temperatures and pressures.
A refrigerant charging chart label is attached to the outside of the
compressor access door. The chart includes the required suction
line temperature at given suction line pressures and outdoor
ambients..
An accurate superheat, thermocouple- or thermistor-type ther-
mometer, and a gage manifold are required when using the
16
55
60
65
—
—
—
818
750
692
1227
1125
1038
1568
1438
1327
1773
1625
1500
scroll
compressor
70
—
—
964
—
1393
units
are
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