Daikin DBC Series Installation Instructions Manual page 13

NOTE: Future adjustments should be made by loosening the belt
tension and increasing or decreasing the pitch diameter of the
sheave by half or full turns as required. Readjust belt tension before
starting drive.
C
B
NOTE: Do not operate sheave with flange projecting beyond the
hub end.
R S
EFRIGERATION YSTEM
The unit is equipped with a thermal expansion valve as a
metering device.
Ensure the hold-down bolts on the compressor are secure and have
not vibrated loose during shipment. Check that vibration grommets
have been installed. Visually check all piping for damage and leaks;
repair if necessary. The entire system has been factory charged
and tested, making it unnecessary to field charge. Factory charges
are shown on the unit's namelate. To confirm charge levels or, if a
leak occurs and charge needs to be added to the system, it is
recommended to evacuate the system and recharge refrigerant to
unit nameplate specifications. This unit has been rated in the
cooling mode at the AHRI rated conditions of: Indoor (80°db /
67°wb) and outdoor (95°db). While operating at this condition,
the subcooling should range from 12° to 15° F for each refrigeration
circuit, for 15 and 20 ton models. Subcooling for 25 ton models
should be from 16° to 19° F for circuit 1, and from 12° to 15° F for
circuit 2.
S -U P C
TART P ROCEDURE AND HECKLIST
NOTE: For models equipped with the DDC controls option, refer to
the supplemental DDC literature supplied with the unit for
additional information.
Begin with power turned off at all disconnects.
1. Turn thermostat system switch to "Cool," and fan switch
to "Auto" and turn temperature setting as high as it will
go.
2. Inspect all registers and set them to the normal open
position.
VL & VM
3. Turn on the electrical supply at the disconnect.
4. Turn the fan switch to the "ON" position. The blower should
operate in low speed after a 7-second delay.
5. Turn the fan switch to "Auto" position. The blower should
stop after a 65 second delay.
6. Slowly lower the cooling temperature until first stage COOL
(LOW COOL) starts. The blower, both fans, and first stage
compressor should now be operating. The blower should
be operating in low speed at 1175 motor rpm. Allow the
unit to run 10 minutes, make sure cool air is being supplied
by the unit.
7. Lower the cooling temperature further until second stage
COOL (HIGH COOL) starts. The blower, both fans, and both
compressors should now be operating. The blower should
be operating in high speed at 1775 motor rpm. Allow the
unit to run 10 minutes, make sure cool air is being supplied
by the unit.
8. Turn the temperature setting to the highest position,
stopping the unit. The indoor blower will continue to run
for 65 seconds.
9. Turn the thermostat system switch to "OFF" and disconnect
all power when servicing the unit.
LOW AMBIENT COOLING NOTES:
For 15 and 20 ton models: 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 is used. This is strongly recommended for 2 Speed
models due to the lower airflow while in the first stage of cooling.
To further protect the compressor from damage during low ambient
conditions, a Freezestat Kit (FSK01) can be added that turns the
compressor off when the evaporator temperature drops too low.
For 25 ton models: The 25 ton units are equipped with a control
that shuts off one condenser fan when the outdoor temperature
is 44° F or below, which enables reliable cooling down to a minimum
ambient temperature of 24°F.
LAKT05, is required below 24° which will enable reliable cooling to
occur to a minimum ambient temperature of 0°F.
HIGH VOLTAGE!
D
ISCONNECT ALL POWER BEFORE SERVICING OR
. M
INSTALLING THIS UNIT
. F
BE PRESENT AILURE TO DO SO MAY CAUSE PROPERTY
,
DAMAGE PERSONAL INJURY OR DEATH
13
An optional Low Ambient kit,
WARNING
ULTIPLE POWER SOURCES MAY
.