Safety Precautions; Thermal Memory Retention Compliance - Danfoss VTT Series Applications And Installation Manual

Table 2
Interior Components
Descriptions

Safety Precautions

Thermal Memory
Retention Compliance
Page 18 of 73
M-AI-VT-001-EN Rev.C.1
Overview of the VTT Compressor
Component
RFI Filter Device to suppress radio frequency interference (RFI).
Control Card Input/output communication and control board.
Power Card Supplies power to the internal components.
Mains Input Three-phase AC power supply to the adjustable frequency drive module.
The rectifier bridge converts the AC input to DC current to supply
Rectifier
inverter power.
DC Bus Intermediate DC bus circuit to handle DC power.
• Filters the immediate DC circuit voltage
• Provides line transient protection
DC reactors • Reduces Root-Mean-Square (RMS) current
• Raises the power factor reflected back to the line
• Reduces harmonics on the AC input
• Stores the DC power
Capacitor bank
• Provides ride-through protection against short power losses
Converts DC into a controlled PWM AC waveform for a controlled variable
Inverter
output to the motor.
Control circuitry Input power, internal processing, output, and motor current are monitored
to provide efficient operation and control.
The back channel provides additional protection in corrosive environments,
Back channel
such as salt air found near sea side applications.
Drive Modules contain high-voltage components
that if handled improperly can result in fatal
injury. Only trained technicians should install and
operate the equipment. No repair work should be
attempted without first disconnecting power to
the drive module and waiting for stored electrical
Discharge Time
Drive Modules contain DC-link capacitors that can remain charged even when the drive module is not powered.
To avoid electrical hazards, disconnect the following:
• AC mains
• Remote DC-link power supplies, including battery backups, uninterruptible power supply (UPS) and DC-link
connections to other drive modules.
Wait 20 minutes for the capacitors to fully discharge before performing any service or repair work.
The Drive Module complies with UL508C thermal
memory retention requirements.
Definition
energy to discharge, a minimum of 20 minutes.
Strict adherence to safety precautions and
notices is mandatory for safe operation of the
drive module.
• • • WARNING • • •
Remarks
Optional
Standard
Standard
Standard
Standard
Standard
Standard
Standard
Standard
Standard
Standard