Upgrade Kit User Manual

2 Regenerative DC Bus Supply Unit (RGU) Upgrade Kit

What You Need To Do

You will make the following changes to the RGU module with this kit:

• Add a LEM (current sensor) to the S phase leg of the RGU module.

• Replace the door on the module, which holds the main control board,

power supply, gate driver board, and isolation board. The new door has

been modified for mounting the power supply and the torroid board

assembly.

• Replace the main control board with a new board, which uses the signal

from the third LEM.

• Add a ferrite core clamp to the ribbon cable which connects the main

control board to the gate driver board.

• Replace the isolation board with a board that handles the burden resistor

needed for the third LEM.

• Add a power supply needed for the third LEM.

• Add a power supply filter board assembly for the power supply on the

gate driver board.

Tools That You Need

• #1 and #2 Phillips screwdrivers

• 3/16” flat blade screwdriver

• Adjustable wrench

• Torque wrench with 75 in-lb (8.5 n-m) capability

• Wire cutters and strippers

Phillips® is a registered trademark of Phillips Screw Company

Before You Begin

• Review the list of parts to insure all items are present before starting the

upgrade.

• This upgrade should take approximately 4 hours to complete.

Step 1. Adding The Third

LEM

1. Turn off and lock out input power. Wait five minutes.

2. Disconnect all sources of power to the unit being modified.

3. Check with a voltmeter to verify that the DC bus voltage has dropped

below 10Vdc.

L1 L2 L3