Daikin RDT Installation And Maintenance Manual page 101

Variable Frequency Drive for VFD Compressor
Never bypass the compressor drive or directly connect the
VFD compressor to the main power supply.
The compressor drive used for this option is a special series
(CDS 303) that is intended for use with an IPM compressor
motor and cannot be replaced with any off the shelf VFD.
The compressor drive is mounted in a separate enclosure
located in condensing section. Auxiliary ventilation is provided
in the enclosure by fans M3 & M4 to protect the compressor
drive from an over temp condition. The ventilation fans operate
in conjunction with the compressor drive. Refer to Figure 18 for
VFD panel layout.
The compressor drive and the LCP (local control panel) are
preset with parameters from the factory and should not need
to be changed in the field. The LCP is removable and is
interchangeable with any of the compressor drives used by
any of the VFD compressors. If the need arises to replace the
compressor drive, the parameters can be downloaded from the
LCP to the new compressor drive.
The compressor drive is preset to run the compressor
clockwise and must be connected as shown in the unit
schematic.
The compressor drive is preset for an open loop configuration
with 0-10Vdc reference corresponding to 1500-6000 Rpm.
The compressor drive drive generates a soft start with an
initial ramp of 2 seconds. In-rush current (or LRA) to the VFD
compressor is typically not more than a few percent more than
rated nominal Current.
Compressor Speed, modulation signal %, frequency signal,
compressor amperage are all displayed in real time on the
compressor drive screen. Alarms and descriptions will also be
visible on the compressor drive screen.
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WARNING
Basic Operation of Compressor Drive:
Start= Connect terminals 12 & 18 for minimum of 5 secs,
connect terminals 12 &27 and terminals 13 &37
Stop= Disconnect terminals 12 & 27
Emergency Stop= Disconnect terminals 13 & 37
Control/Modulation= 0 to 10Vdc signal to terminals 53 & 55
Run Verification= A contact closure from relay 02 (terminals
04 & 05) is provided when drive is running
Oil Injection= A contact closure from relay 01 (terminals 01 &
02) is provided when compressor speed is greater than 50 rps
(3000 rpm) which energizes the oil solenoid coil.
The compressor drive contains protection for the compressor
against short circuits at the compressor terminals, overload
protection , phase loss and earth faults. The compressor drive
is protected against short-circuits.
Table 22: Compressor Drive Model & Frame Size
Compressor
Drive Model
Model
VZH-088B CDS303-15kW
VZH-117B CDS303-18kW
VZH-170B CDS303-22kW
Refer to the VFD operational manual for more information.
101 IM 893-10 • ROOFPAK SINGLEZONE UNITS
u o
nIT PTIons
Frame Size
208-230V 460V
B4 B3
C3 B4
C3 B4