Daikin DCG Series Service Instructions Manual page 36

SYSTEM OPERATION
S - P
TART UP ROCEDURE AND
Models with a V in the 11th position of the model number.
For 2 speed models, the indoor blower will operate on low
speed when in "Fan Only" mode or while in first stage
"Cooling" mode. Unit will operate on high speed in "Heat-
ing" mode and while in second stage "Cooling" mode.
The start-up procedure is the same as for "Air Conditioning
Start-up Procedure" with the understanding that in Step 6, the
indoor blower will run at low speed (~1175 motor rpm) and in
Step 7, the indoor blower will operate at high speed (~1775
motor rpm).
NOTE: While in the Cooling Mode, to prevent frost from
forming on the evaporator while the unit is operating in
outdoor temperatures of 65°F or lower, it is recommended
that a low ambient kit (LAKT-**) is used. This is strongly
recommended for 2 Speed models due to the lower airflow
while in the first stage cooling. To further protect the
compressor from damage during low ambient conditions, a
Freezestat Kit (FSK***) can be added that turns the
compressor off when the evaporator temperature drops too
low.
B C
EARING HECK
Prior to energizing any fans, check and make sure that all
setscrews are tight so that bearings are properly secured to
shafts.
GAS SYSTEM
Flame Sensor and Ignition Electrode Location
MAXIMUM NUMBER
MAXIMUM
INPUT of
BTUH/BURNER
(BTUH) BURNERS
210,000 6
36
C 2 S M
HECKLIST FOR PEED
FLAME
SENSOR
GAS ORIFICES
NATURAL PROPANE (LP)
(Dia)
35,000 #34
Heat Exchanger and Burner Orifice
:
ODELS
NOTE: Gas appliances located more than 2000 feet above
sea level must be derated 4% per 1000 feet of total
elevation and that variance in gas heating value and
specific gravity require change in manifold pressure to
obtain rating, it is mandatory that the input be adjusted at
the installation site. All installations should be made as
outlined in the latest edition of the National Fuel Gas Code
ANSI Z223.1,section "Procedures To Be Followed To Place
An Appliance in Operation". Refer also to the "User's
Information Manual" supplied with the unit for additional
information on the gas furnace.
NORMAL SEQUENCE OF OPERATION
NOTE: The ignition control board blower off delay is factory
set at 150 seconds. This factory setting can also be set to 120
or 135 seconds by placing the jumper on the desired setting.
H
EATING
This unit has one (RS) Manual Reset Limit Control Switch.
Check the limit to make sure it has not tripped. The limit may
arrive at the job site tripped as a result of shipping shock.
If the ventermotor comes on, but the unit does not attempt
ignition, check if the ALS (Auxiliary High Limit Control
Switch) requires resetting.
1. With electricity and gas turned on, the system switch in
the "HEAT" or "AUTO" position and the fan switch in the
"AUTO" position, the thermostat will close the circuit
between unit terminals R and W (R-W) when the tem-
perature falls below the thermostat setting.
2. D1 on IIC energizes relay IDMR.
3. Relay IDMR energizes the ventermotor IDM.
4. Operation of the ventermotor closes the pressure switch
PS located in the burner compartment. Unless excessive
temperatures or shipping shock have opened high limit
control ALS, power is fed to the integrated ignition
control, which then initiates a 15-second pre-purge time
delay. During this period, the ventermotor will clear the
combustion chamber of any residual gas.
5. After the pre-purge period, the ignition control energizes
the Wl-C gas valve and simultaneously initiates a "three
(3)-try" spark ignition sequence.
6. When the burners are ignited, a minimum one (1) micro-
amp DC current will flow through the flame between the
sensor electrode and the grounded burner.
7. When the controller proves that the flame has been
established, it will keep the gas valve energized and
discontinue the ignition spark. High stage manifold pres-
sure will be approximately 3.5" w.c. for natural gas and
10.0" w.c. for propane (LP). Low fire natural gas is 2.0"
(Dia)
w.c.; low fire propane 6.0" w.c.
#52
8. If the control is unable to ignite the burners after its initial
attempt, it will initiate another purge and spark se-
Specifications