Air Flow Adjustments - Daikin DCC Series Installation Instructions Manual

Utilization Voltage - The voltage of the line terminals of the equip-
ment at which the equipment must give fully satisfactory perfor-
mance. Once it is established that supply voltage will be main-
tained within the utilization range under all system conditions,
check and calculate if an unbalanced condition exists between
phases. Calculate percent voltage unbalance as follows:
Three Phase Models Only
3) PERCENT VOLTAGE
= 100 X
UNBALANCE
HOW TO USE THE FORMULA:
EXAMPLE: With voltage of 220, 216, and 213
1) Average Voltage = 220+216+213=649 / 3 = 216
2) Maximum Voltage Deviations from Average Voltage = 220 - 216 = 4
3) Percent Voltage Unbalance = 100 x
Percent voltage unbalance MUST NOT exceed 2%

AIR FLOW ADJUSTMENTS

The drive on the supply fan is typically set in the middle of the
RPM range. The drive motor sheave pitch diameter is field adjust-
able for the required airflow. Refer to "Drive Adjustments" section
below.
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. 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 bear-
ing life and vibration free operation. Initially, it is best to have a
variable pitched motor sheave for the purpose of airflow balanc-
ing, but once the balance has been achieved, fixed sheaves main-
tain alignment and minimize vibration more effectively. For direct
drive units, move green wire for fan.
NOTE: Never run CFM below 350 CFM per ton, evaporator freezing
or poor unit performance is possible.
PSC M
OTOR
Adjust the CFM for the unit by changing the speed tap of the in-
door blower motor at the EBTDR "com" connection with the one
of the speed taps on "M1" or "M2" (Black-High Speed, Blue-Me-
dium Speed, Red-Low Speed).
EEM M
OTOR
Adjust the CFM for the unit by changing the position of the low
voltage leads on the motor terminal block. Green is for Fan Only.
Yellow is for Cooling and Heat Pump Heating. Refer to Appendix A
for blower performance at each speed tap. NOTE: If more than
one lead is energized simultaneously, the motor will run at the
higher speed.
2) MAXIMUM VOLTAGE DEVIATIONS
FROM AVERAGE VOLTAGE
1) AVERAGE VOLTAGE
4
400
= = 1.8%
216 216
.
E F R
VAPORATOR AN OTATION
Check that fan rotates counter-clockwise when viewed from the
drive side of unit and in accordance with rotation arrow shown on
blower housing. If it does not, reverse the two incoming power
cables. 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 (see Appendix B).
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 adjust-
able for the required airflow. Refer to "Motor Sheave Adjustmens"
section.
Upon completion of the air flow balancing, we recommend re-
placing 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 balanc-
ing, but once the balance has been achieved, fixed sheaves main-
tain alignment and minimize vibration more effectively. For direct
drive units, move fan speed wire.
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.
For heat pump units, the airflow must be adjusted so that the air
temperature rise falls within the ranges given stated on Data Plate
(see Appendix A - Blower Performance).
S E F R
ET VAPORATOR AN PM
Actual RPM's must be set and verified with a tachometer or strobe
light. Refer to Appendices A and B for basic unit fan RPM. Refer
also to "Airflow" section of this manual. With disconnect switch
open, disconnect thermostat 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.
T A A
ENSION AND LIGNMENT
Correct belt tension is very important to the life of your belt. Too
loose a belt will shorten its life; too tight, premature motor and
bearing failure will occur. Check you belt drive for adequate "run-
in" belt tension by measuring the force required to deflect the
belt at the midpoint of the span length. Belt tension force can be
measured using a belt tension gauge, available through most belt
drive manufacturers.
10
C (T P M
HECK HREE HASE ODELS
DJUSTMENT
O )
NLY