DS200DCFBG1B

DS200DCFBG1B is a DC Power Supply Feedback Board manufactured and designed by General Electric. It used in EX2000, DC2000, CB2000, FC2000, GF2000, ME2000, and AC2000, IGBT drive applications. The EX2000 uses the board for a different purpose than the drive does. The DCFB power supply board receives thirty-eight (38) and 115 VAC (24 VDC) input power from the control power transformer (CPT) and provides control level power to the drive and 115 VAC power to the enclosure fans.

Features

The DCFB board includes the following circuits.

• Control level power supplies (+5, +/- 15 and +/- 24 VDC)
• Motor field power circuits (Except the SCR Module)
• Driver circuits for the motor field SCR gate pulse generators.

Circuits to monitor numerous AC line & DC motor signals including

• Armature current and voltages
• Motor field current
• AC line current
• AC line Voltage magnitude and phase sequence.

Characteristics

• DCFB boards include twelve configurable jumpers ( thirteen (13) on REV BKC and later boards) and seven DIP switches for the selection of customer options; most jumpers and DIP Switch selections are factory set.
• The +24 V dc supply is used by the DCFB board to produce a +5 V dc, 4 A output as well. When the +5 V dc supply is regulated, the /PSEN signal on 2PL enters a TTL low state. If the +5 V dc supply is not regulated, the signal enters a high state. When set to high, /PSEN causes the Drive Control Card's (SDCC/LDCC) microprocessor to reset.
• The armature current feedback circuits are powered by isolated +5 and 15 V dc supplies from the DCFB board. Fuse numbers FU2 and FU3 guard the power supply outputs against short circuits (7 A, 2AG). For these fuses, light-emitting diodes (LEDs) CR51 and CR55 offer blown fuse indications. Fuse FU1 (1/2 A, 2AG) is used to protect the 115 V ac output. Blowing fuses are indicated for FU1 by the neon light LT1.

Voltage and Current Feedback VCO

Voltage-controlled oscillator (VCO) circuits on the DCFB board transform input voltages into frequency signals. The nominal output frequency of each VCO is 250 kHz. Depending on the input voltage, the output frequency ranges from 0 to 500 kHz. Through connection 1PL, VCO outputs are transmitted to the SDCC/LDCC board to provide the following feedback:

• SCR bridge ac input voltage
• Output bridge voltage
• Motor voltage (NA)
• Millivolt signals from field shunts
• Millivolt signals from armature shunts

Through connector 1PL, pin 13, the output bridge VCO circuit communicates feedback to the SDCC/LDCC board (1PL- 13). Scaling the voltage provided to the circuit is accomplished using DIP switch SW4. Testpoint TP37 on the SDCC/LDCC board receives a diagnostic signal through 1PL-37 from a frequency-to-voltage reconstruction circuit. An ac-coupled oscilloscope can be used to see the diagnostic bridge voltage signal. Through 1PL-39, the second VCO communicates motor voltage feedback to the SDCC/LDCC board. Scaling the voltage provided to the circuit is accomplished using DIP switch SW5