Rockwell Automation Liqui-Flo AC Power Modules - Manual (Page 20)

2-8 LiquiFlo AC Power Modules, Hardware Reference Version 6.4
2.6 Regulator Board Description
LiquiFlo drive regulation is performed by a microprocessor on the Regulator board.
See figure 2.5. Drive operation is adjusted by the parameters entered through the
keypad. The Regulator board accepts power circuit feedback signals and an external
speed reference signal, as well as data from an encoder that is attached to the motor
when set up for FVC regulation. The Regulator board provides:
• PWM gating signals to the IGBT power devices
Based on the output of the control loop, the regulator sends PWM gating signals to
isolated drivers on the Gate Driver board. These drivers switch the Insulated Gate
Bi-polar Transistors (IGBTs), producing a waveform that corresponds to the voltage
and frequency outputs of the inner V/Hz, FVC, or SVC regulators. The IGBTs can be
switched at either a 2, 4, or 8 kHz carrier frequency.
• Form A and B contacts for drive status indicators
The Form A and B contacts are under control of the user via programmable
parameters. A Form A or B transition can indicate drive status. The contacts are
rated for 5 amps resistive load at 250 VAC/30 VDC and are made available through
the terminal strip.
• Display data for a four-character display and fourteen indicator LEDs
For a description of the keypad/display refer to section 2.6.6. For operational
instructions, see the LiquiFlo Software Reference manual (D2-3410).
• An analog output
The analog output is a scaled voltage (0-10 VDC) or current (4-20 mA) signal
proportional to either motor speed (RPM), motor torque, or current (%TORQUE).
The current signal selection (via jumper J17) requires a power supply for operation.
The power can be sourced from the encoder terminals (4 and 9) or from an external
15 V power supply. See table 7.1, terminals 10 and 11, for more information. The
analog output signal is available through the terminal strip.