Rockwell Automation SB3000 AC Power Modules - Manual (Page 14)

2-2 SB3000 Power Modules (Rittal)
Capacitor Bank Assembly
The capacitor bank's electrolytic capacitors store DC power from the IGBTs.
DC Bus Voltage Meter
The DC Bus Voltage meter, which is connected directly across the DC bus, measures
the DC bus voltage being supplied by the SB3000 Power Module.
AC Input Current Meter and DC Bus Current Meter
The AC Input Current and DC Bus Current meters measure the AC input current being
provided to the Power Module and the DC bus output current supplied by the SB3000
Power Module. These meters are connected to the PMI meter ports on the PMI
Processor. The meters are calibrated for +/-10V or +10V at full scale. See table 2.1.
Note that PMI ports 3 and 4 are not used.
The AC Input Current meter indicates the RMS line current flowing into or out of the
SB3000 Power Module. The current level is derived from the feedback signals coming
from the Hall devices on the AC input leads to the phase modules.
The DC Bus Current meter indicates the DC current level produced by the SB3000
Power Module. The value is scaled from the feedback signal coming from the Hall
device monitoring the Power Module’s DC output current. Its range is bi-directional.
Positive current indicates that current is flowing from the rectifier to the load (motoring)
and negative current indicates current flowing into the rectifier from the load
(regenerating) to the AC line.
Softcharge Assembly
The Softcharge assembly is mounted separately and consists of pre-charge resistors
and a contactor. The contactor bypasses the pre-charge resistors after the bus voltage
reaches a programmable threshold value. A pre-charge contactor module
communicates with the LPI module and controls the contactor. See figure 2.1.
Table 2.1 – Meter Scaling
SB3000 AC Input
Current Rating at
4 kHz
PMI Processor Port 1
DC Bus Current Meter
Scaling
PMI Processor Port 2
AC Input Current Meter
Scaling
445 Amp -800 to +800A 0 to 600A
890 Amp -1,200 to +1,200A 0 to 1,000A
1,335 Amp -1,800 to +1,800A 0 to 1,500A