Goodmans COMMERCIAL HEATING & COOLING 3 TON - 6 TON PACKAGE GAS UNIT CPG SERIES - Manual (Page 20)

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9. Integrated ignition control will close its normally open
contacts after a delay of approximately 30 seconds.
This action energizes contactor BC and starts the
supply fan motor. Operation of the supply fan
circulates air across the heat exchanger and delivers
heated air to the conditioned space.
10. When the space temperature rises, the thermostat
will open R-W. Opening R-W will cause the gas valve
to close, and the furnace to shut down.
11. The furnace has three high temperature limit controls,
which can shut down the burner. They do not shut
down the ventermotor.
A
UTOMATIC
R
ESET
H
IGH
L
IMIT
C
ONTROL
(LS)
Located in the burner compartment on the heat exchanger,
its sensing element projects through the blower section bulk-
head and senses the temperature at the rear of the furnace.
It will cycle the furnace off if the temperature exceeds 100°F
plus maximum rise.
A UXILIARY H IGH L IMIT C ONTROL (ALS)
Located in the blower compartment on the blower housing, it
senses air temperature within the blower compartment and
protects the filters from excessive temperature. It will shut
down the furnace if it senses excessive temperatures.
M ANUAL R ESET F LAME R OLLOUT C ONTROL (RS)
Located in the burner compartment at the top of the burner
assembly, it senses high temperature that could occur if the
heat exchanger tubes were plugged and the flame was roll-
ing out instead of entering the tubes. It has a manual push-
button reset that cannot be actuated until the limit control has
cooled.
TROUBLESHOOTING
I
GNITION
C
ONTROL
E
RROR
C
ODES
The following presents probable causes of questionable unit
operation. Refer to Diagnostic Indicator Chart for an inter-
pretation of the signal and to this section for an explanation.
Remove the control box access panel and note the number
of diagnostic LED flashes. Refer to Diagnostic Indicator Chart
for an interpretation of the signal and to this section for an
explanation.
A
BNORMAL
O
PERATION
- H
EATING
Internal Control Failure
If the integrated ignition control in this unit encounters an in-
ternal fault, it will go into a “hard” lockout and turn off the
diagnostic LED. If diagnostic LED indicates an internal fault,
check power supply to unit for proper voltage, check all fuses,
circuit breakers and wiring. Disconnect electric power for
five seconds. If LED remains off after restoring power, re-
place control.
External Lockout
An external lockout occurs if the integrated ignition control
determines that a measurable combustion cannot be estab-
lished within three (3) consecutive ignition attempts. If flame
is not established within the seven (7) second trial for igni-
tion, the gas valve is deenergized, 15 second inter-purge cycle
is completed, and ignition is reattempted. The control will
repeat this routine three times if a measurable combustion is
not established. The control will then shut off the induced
draft blower and go into a lockout state.
If flame is established but lost, the control will energize the
circulator blower at the heat speed and then begin a new
ignition sequence. If flame is established then lost on subse-
quent attempts, the control will recycle for four (4) consecu-
tive ignition attempts (five attempts total) before locking out.
The diagnostic fault code is 1 flash for a lockout due to failed
ignition attempts or flame dropouts. The integrated control
will automatically reset after one hour, or it can be reset by
removing the thermostat signal or disconnecting the electri-
cal power supply for over five seconds. If the diagnostic LED
indicates an external lockout, perform the following checks:
• Check the supply and manifold pressures
• Check the gas orifices for debris
• Check gas valve for proper operation
• Check secondary limit
A dirty filter, excessive duct static, insufficient air
flow, a faulty limit, or a failed circulator blower can
cause this limit to open. Check filters, total external
duct static, circulator blower motor, blower motor
speed tap (see wiring diagram), and limit. An
interruption in electrical power during a heating
cycle may also cause the auxiliary limit to open.
The automatic reset secondary limit is located on
top of the circulator blower assembly.
• Check rollout limit
If the burner flames are not properly drawn into
the heat exchanger, the flame rollout protection
device will open. Possible causes are restricted
or blocked flue passages, blocked or cracked heat
exchanger, a failed induced draft blower, or
insufficient combustion air. The rollout protection
device is a manual reset limit located on the burner
bracket. The cause of the flame rollout must be
determined and corrected before resetting the limit.
• Check flame sensor
A drop in flame signal can be caused by nearly
invisible coating on the sensor. Remove the sensor
and carefully clean with steel wool.
• Check wiring
Check wiring for opens/shorts and miswiring.
IMPORTANT: If you have to frequently reset your gas/electric
package unit, it means that a problem exists that should be
corrected. Contact a qualified servicer for further information.