Rockwell Automation SB3000 AC Power Modules - Manual (Page 49)

Diagnostics and Troubleshooting 4-11
Step 8. Install the replacement SB3000 Power Module cabinet by following these
steps in reverse order.
4.5 Replacing Power Module Sub-Assemblies
Use the procedures in sections 4.5.1 to 4.5.4 to replace the SB3000 Power Module’s
fuses and sub-assemblies.
4.5.1 Replacing Fuses
Use the following procedure to replace a fuse that has blown:
Step 1. Turn off and lock out the AC input power.
Step 2. Wait ten minutes to allow the DC bus voltage to dissipate.
Step 3. Look at the built-in DC Bus Voltage meter. When the DC bus potential is
down to zero volts, open the SB3000 Power Module cabinet's doors and
measure the DC bus potential across the DC bus bars, 1247 A,B,C (+ bus)
and 1145 A,B,C (- bus), with an external voltmeter before working on the unit.
See figure 4.1.
Step 4. Remove the blown fuse and install the replacement fuse. Figures 4.2, 4.3,
and 4.4 show the location of the fuses in the 445A, 890A, and 1335A SB3000
Power Modules. Table 4.5 provides fuse specifications.
Step 5. Close the cabinet doors and reapply power to the SB3000 Power Module.
!
ATTENTION: DC bus capacitors retain hazardous voltages after input
power has been disconnected. After disconnecting input power, wait ten
(10) minutes for the DC bus capacitors to discharge, then look at the
built-in DC bus voltage meter. When the voltage is down to zero (0) volts,
open the cabinet doors and check the voltage across the DC bus bars,
1247 A,B,C (+ bus) and 1145 A,B,C (- bus), with an external voltmeter
to ensure the DC bus capacitors are discharged before touching any
internal components. Failure to observe this precaution could result in
severe bodily injury or loss of life.