Rockwell Automation SA3000 High Power Modules - Manual (Page 50)

4-18 High Power SA3000 AC Power Modules
Step 3. Open the Power Module cabinet's doors and measure the DC bus potential
across each pair of DC bus bars, 347 A,B,C (+ bus) and 345 A,B,C (- bus),
with an external voltmeter before working on the unit. See figure 4.1.
Step 4. Remove the bracket that is fastened across the cabinet in front of the
pre-charge assembly. The bracket is attached to the cabinet with two screws.
Step 5. Remove the two power cables marked with a red band from the pre-charge
assembly.
Step 6. Remove the wiring control harnesses. Do not remove the CN104 cable on
the pre-charge module itself.
Step 7. Remove the power cables marked with a gray band from the DC bus
capacitors.
Step 8. Remove the control wiring that connects to the capacitor bank.
Step 9. Remove the four screws that fasten the pre-charge assembly to the back
panel of the cabinet.
Step 10. Remove the pre-charge assembly.
Step 11. Install the new pre-charge assembly by following steps 1 through 10 in
reverse order.
Step 12. Close the cabinet doors.
Step 13. Reapply power to the Power Module.
4.4.4 Replacing a Blower Assembly
Use the following procedure to replace a blower assembly:
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. Open the cabinet doors and check the voltage across the DC bus bars,
347 A,B,C (+ bus) and 345 A,B,C (- bus), with an external voltmeter to ensure
the DC bus capacitors are discharged before touching any internal
components. See figure 4.1.
Step 4. Turn off the AC power to the blower by turning the circuit breaker in the power
supply panel off.
Step 5. Disconnect the wires from the right side of the blower assembly. The wire
connectors are keyed.
Step 6. Remove the blower from the cabinet by sliding it out.
!
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. Open the cabinet
doors and check the voltage across the DC bus bars, 347 A,B,C (+ bus)
and 345 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.