Rockwell Automation SB3000 Configuration and Programming - Manual (Page 113)

Discharging the DC Bus H-1
A
PPENDIX
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Discharging the DC Bus
Observe the following precautions to safely discharge the SB3000 Rectifier’s DC bus
capacitors before performing any service or maintenance on the rectifier. Refer to
instruction manual S-30xx, Distributed Power System High Power SB3000 Power
Modules, for information regarding test points, component locations, and
troubleshooting and maintenance procedures.
• Disconnect, lock out, and tag three-phase AC input power.
• Wait five minutes to allow the DC bus voltage to dissipate.
• Look at the built-in DC Bus voltmeter. When the DC bus potential is down to
approximately zero volts, open the Power Module cabinet doors and measure the
DC bus potential across the DC bus bars, 1247 A (+ bus) and 1145A (- bus), with an
external voltmeter before working on the unit.
!
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.