Normal Sequence Of Operation - Cooling - Daikin DFG Series Installation Instructions Manual

7.1 Turn power to the unit OFF.
7.2 Switch any two leads of power supply at unit Single
Point Power Block.
7.3 Turn power to the unit ON.
7.4 Perform step 7 again.
8. Turn the temperature setting to the highest position,
stopping the unit. The indoor blower will continue to run
for 60 seconds. On units with DDC controls installed, use
Test/Balance Menu to force the unit to Vent Mode. This
test bypasses internal delays.
9. Turn the thermostat system switch to "OFF". On units
with DDC controls installed, use Test/Balance Menu to
disable Force Mode operation and allow the unit to re-
turn to normal operation.
Final System Checks
10. Check to see if all supply and return air grilles are adjust-
ed and the air distribution system is balanced for the best
compromise between heating and cooling.
11. Check for air leaks in the ductwork. See Sections on Air
Flow Adjustments.
12. Make sure the unit free of "rattles", and the tubing in the
unit is free from excessive vibration. Also make sure tubes
or lines are not rubbing against each other or sheet metal
surfaces or edges. If so, correct the trouble.
13. Set the thermostat at the appropriate setting for cooling
and heating or automatic changeover for normal use.
14. Be sure the Owner is instructed on the unit operation,
filter, servicing, correct thermostat operation, ect.
Refrigeration Performance Check
Check that compressor RLA corresponds to values shown in Ap-
pendix B. RLA draw can be much lower than values listed at low
load conditions and low ambient condensing temperatures. Val-
ues in Appendix B can slightly exceed at high load conditions and
high ambient condensing temperatures.
HIGH VOLTAGE
Disconnect all power before servicing or
installing this unit. Multiple power sources
may be present. Failure to do so may cause
property damage, personal injury or death.

NORMAL SEQUENCE OF OPERATION - COOLING

Refrigeration Sequence Check
With the disconnect switch open, remove the field connected
thermostat wire from terminal R on TB1 terminal block. Place a
jumper across terminals R and G, and across R and Y on TB1 termi-
nal block. Close the disconnect switch. The following operational
sequence should be observed.
WARNING
1. Current through primary winding of transformer TRANS1
energizes the 24-volt control circuit.
2. To simulate a mechanical call for cooling from the wall
thermostat, place a jumper across terminals R and Y1 of
terminal block TB1.
3. UNIT WITH ECONOMIZER OPTION: The compressor circuit
is interlocked through terminals 3 and 4 of the economiz-
er module. If the outdoor air enthalpy (temperature and
humidity) is not suitable for cooling, the economizer termi-
nals will be closed permitting compressor to be energized.
4. The blower contactor closes its contacts L1, L2 and L3 to
T1, T2 and T3 to provide power to the supply fan motor.
5. Compressor contactor closes its contacts L1, L2 and L3 to
T1, T2 and T3 to provide power to the compressor motor
COMP 1; COMP 2, if conditions are correct. In addition,
contactor C1 closes its contact L3 to T3 , energizing the
condenser fan motor.
BURN HAZARD!
DO NOT TOUCH! DISCHARGE LINE MAY BE HOT!
6. Check that each compressor is operating correctly. The
scroll compressors in these units MUST operate in the
proper rotation. To ensure the compressors are operating
in the correct direction, check the compressor discharge
line pressure or temperature after each compressor is
started.
The discharge pressure and discharge line temperature
should increase. If this does not occur and the compres-
sor is producing an exceptional amount of noise, perform
the following checks.
• Ensure all compressors are operating in the proper
direction. If a single motor is operating backwards,
check the power wiring for that motor and correct any
leads that have been interchanged at the contactor or
at the motor.
7. With all safety devices closed, the system will continue
cooling operation until the thermostat is satisfied.
8. Disconnecting the jumper wire between R and Y1 and Y2
and between R and G on TB1 terminal block will simulate
a satisfied thermostat. The compressors will cycle off and
IIC (pin 12) will initiate its time delay cycle. The compres-
sor and the supply fan will cycle off.
9. After a time delay of approximately 3 minutes, the com-
pressor control circuits will be ready to respond to a sub-
sequent call for cooling from the wall thermostat.
10. Open disconnect switch. Reconnect the field thermostat
wire at terminal R on terminal block TB1.
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WARNING