Danfoss Turbocor TT-300, Service Manual

Page: 52 / 132

52 of 132 M-SV-001-EN Rev.E
Compressor Components
3.7 Inverter
3.7.1 Function
3.7.2 Connections
The function of the Inverter (also known as the
IGBT) is to take the DC bus voltage as an input
and generate the AC output voltage to the
compressor motor at the required fundamental
frequency to generate the requested shaft speed.
Voltage to the motor is also controlled to provide
the appropriate motor torque.
The Backplane sends +24VDC and gating signals
to the Inverter from the BMCC. In return, the
Inverter sends current, temperature, error, and
DC bus voltage information to the BMCC via the
Backplane. Motor currents and voltages displayed
in the SMT cannot be directly compared or
correlated to incoming 3-phase AC values.
In the event of a 3-phase voltage power loss
while the compressor is running, the Inverter
switches to Generator Mode, acting as a rectifier
to maintain the DC bus voltage until the shaft
comes to a complete stop and de-levitates.
See Figure 43 (Inverter Connections) for
connection locations of the Inverter.
Figure 43 - Inverter
Connections