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Customers are responsible for all field wiring with
respect to EMC and EMI interference. Customers are
responsible for mitigating the risks associated with
EMC and EMI interference that can occur as a result of
customer-provided field wiring as dictated by
international, national, and local codes. This also
implies that customers are responsible for incoming
power wiring to the drive with respect to EMC and EMI
interference.
All customer wiring, including power wiring to drives,
must be separated: 24–27 Vdc, 110–120 Vac, and 380–
600 Vac each must be in separate conduit runs.
The customer is required to provide an overcurrent
protective device upstream of all drives in accordance with
IEC standards and/or any applicable national and local and
codes.
Service personnel must use proper PPE for servicing and
must also use proper lockout/tagout procedures during
servicing: lock the drive disconnect handle before
servicing to prevent accidental pulling of disconnect
handle at the drive panel.
In addition, service personnel should disconnect the main
supply disconnecting device upstream of the drive before
performing any service on any part of the chiller.
AFDE Information
The AFDE refrigerant-cooled Adaptive Frequency Drive is
a pulse width modulated (PWM) design incorporating
both an IGBT (Insulated Gate Bipolar Transistor) active
rectifier and inverter. It is designed for 380–480 volt
application. This drive converts AC power to DC power and
back to AC power. The incoming 380–480 volts are
converted to a constant 700 Vdc by the active rectifier, and
into a section of capacitors that are used to store the DC
voltage. The DC output feeds the inverter IGBTs that switch
at predetermined time to change the DC input voltage to a
symmetrical AC output voltage of desired magnitude and
frequency. The output frequency range is 38 to 60 hertz.
The DC voltage is fixed at 700 Vdc. A variable output is
accomplished by PWM control within the inverter by the
IGBTs which are basically transistors that turn on and off
in response to the gate driver.
A combination of two distinct operating modes make up
the AFDE control within the chiller's UC800 control. First
by controlling the inlet vanes, and second by modulating
impeller speed from 38 to 60 hertz. The IGBTs control the
speed in response to the UC800 compressor control
signal. Circuit breakers, surge capacitors and ground
faults are standard on all AFDE units.
Some of the basic principles of the drive are:
•
Less than or equal to 5 percent current harmonic
distortion (TDD).
•
Minimum efficiency of 97 percent at rated load and
60 Hz.
AFDE-SVU02F-EN
•
Unit displacement power factor of 0.98 or better at full
load and a value of 0.96 at part load.
•
Low in rush current.
•
The current never exceeds the full load amps.
•
The AFDE varies the motor speed in response to the
speed command from the UC800 control.
The CenTraVac™ Control Panel has full control of the unit
operation, including the start/stop functions. If you
encounter a fault condition or an alarm on the drive, the
Tracer® AdaptiView™ display will indicate "alarm" and an
"alarm message."
This manual covers the features and specifications that are
unique to the Trane Adaptive Frequency Drives being
produced for Trane. Only product information is covered
here that supplements that presented in the standard
LiquiFlo instruction manuals that ship with the unit.
Overview
11
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