Daikin DCG Series Service Instructions Manual page 35

SYSTEM OPERATION
O , F C
BSTRUCTIONS AN LEARANCE AND
Remove any extraneous construction and shipping materials
that may be found during this procedure. Rotate all fans
manually to check for proper clearances and that they rotate
freely. Check for bolts and screws that may have jarred loose
during shipment to the job site. Retighten if necessary. Re-
tighten all electrical connections.
F D C
IELD UCT ONNECTIONS
Verify that all duct connections are tight and that there is no
air bypass between supply and return.
F S C
ILTER ECTION HECK
Remove filter section access panels and check that filters are
properly installed. Note airflow arrows on filter frames.
P - P
RE STARTUP RECAUTIONS
T I
RANSFORMER AND NDUCED
NOTE: On the 208/230 volt units only.
Ensure the transformer and induced draft motor are set on the
appropriate voltage taps. Both the transformer tap and in-
duced draft motor are set on 230v from the factory. To change
the induced draft motor voltage, remove the black induced
draft motor wire from the unused terminal on the ignition
control board and swap it with the red wire coming from the
induced draft motor.
It is important to your safety that the unit has been properly
grounded during installation. Check ground lug connection in
main control box for tightness prior to closing circuit breaker
or disconnect switch. Verify that supply voltage on line side
of disconnect agrees with voltage on unit identification plate
and is within the utilization voltage range.
System Voltage - That nominal voltage value assigned to a
circuit or system for the purpose of designating its voltage
class.
Nameplate Voltage - That voltage assigned to a piece of
equipment for the purpose of designating its voltage class and
for the purpose of defining the minimum and maximum
voltage at which the equipment will operate.
AIR FLOW ADJUSTMENTS
When the final adjustments are complete, the current draw of
the motor should be checked and compared to the full load
current rating of the motor. The amperage must not exceed
the service factor stamped on the motor nameplate. The total
airflow must not be less than that required for operation of the
electric heaters or the furnace.
If an economizer is installed, check the unit operating
balance with the economizer at full outside air and at
minimum outside air.
W
IRING
D M
RAFT OTOR
NOTE: Airflow setting below 300 CFM /Ton is not
recommended, as evaporator freezing or poor unit
performance is possible.
S E F R
ET VAPORATOR AN PM
Actual RPM's must be set and verified with a tachometer or
strobe light. With disconnect switch open, disconnect ther-
mostat wires from terminals Y and W. This will prevent
heating and mechanical cooling from coming on. Place a
jumper wire across terminals R and G at TB1 terminal block.
Close disconnect switch; evaporator fan motor will operate so
RPM can be checked.
For gas heat units, the airflow must be adjusted so that the
air temperature rise falls within the ranges given stated on
Data Plate.
E F R
VAPORATOR AN OTATION
O )
NLY
Check that fan rotates clockwise when viewed from the drive
side of unit and in accordance with rotation arrow shown on
blower housing. If it does not, reverse any two incoming power
cables at Single Point Power Block. In this case, repeat
bearing check.
Do not attempt to change load side wiring. Internal wiring
assures all motors and compressors will rotate in correct
direction once evaporator fan motor rotation check has been
made.
E I C
LECTRICAL NPUT HECK
Make preliminary check of evaporator fan ampere draw and
verify that motor nameplate amps are not exceeded. A final
check of amp draw should be made upon completion of air
balancing of the duct system .
2 SPEED MODELS
NOTE: For 2 Speed Models, airflow adjustments must be
made on high speed, i.e., 2nd stage cooling or in heat
mode.
BELT DRIVE MODELS ONLY
The drive on the supply fan is typically set in the middle of the
RPM range. The drive motor sheave pitch diameter is field
adjustable for the required airflow.
Upon completion of the air flow balancing, we recommend
replacing the variable pitched motor sheave with a properly-
sized fixed sheave. A matching fixed sheave will provide
longer belt and bearing life and vibration free operation.
Initially, it is best to have a variable pitched motor sheave for
the purpose of airflow balancing, but once the balance has
been achieved, fixed sheaves maintain alignment and mini-
mize vibration more effectively. For direct drive units, move fan
speed wire.
C (T P M
HECK HREE HASE ODELS
35