Siemens 6SR41 series Product User Manual page 79

Cells are typically switched at 600 Hz per pole, with an output switching frequency of
1200 Hz per cell. The total effective drive output switching frequency with 9 cells is 3600 Hz
(6000 Hz for 15 cells). At this switching frequency, the output (motor) frequency can increase
to 167 Hz. At motor frequencies beyond 167 Hz, its recommended to switch the cells faster.
The cells can switch (with current de-rating) as high as 1200 Hz per pole, which allows a
maximum output (motor) frequency of 330 Hz.
Communications
The Cell Control Board (CCB) communicates with the NXG Controller via a duplex fiber optic
cable using a proprietary protocol.
Protection Features
The Cell Control Board (CCB) contains circuitry and firmware that protects the cell from the
following abnormal operating conditions:
● DC Bus Over-Voltage
● DC Bus Under-Voltage
● Control Power Loss
● Capacitor Voltage Sharing
● IGBT Out of Saturation
● Cell Over-Temperature
● IGBT Device Failure
● AC Bus Under-Voltage
● Communication Fault
These conditions are interrogated by the main NXG Controller and may result in a Cell Fault,
which inhibits the power cell output.
Indicators and Labels
Figure " Indicatiors and Labels" illustrates the indicator functions and labels of the Power
Cell. Particular attention should be paid to the DC bus voltage-indicator LED that shows that
more than 50 VDC is present on the DC bus. This indicator light is located on the front of
each cell's Cell Control Board (and may not be visible until the cell doors are opened). The
cell should not be touched, removed, or serviced if the indicator is illuminated.
Remember that the cell chassis is not grounded and when energized can float to lethal
voltages.
Product User Manual
Operating Instructions, Version AE 12/2009, A5E01454341C
DANGER
Product Description
5.3 Cabinet Details
77