Rockwell Automation 20T PowerFlex Diode Bus Supply - Manual (Page 22)

1-10 Installation/Wiring
PowerFlex Diode Bus Supply User Manual
Publication 20T-UM001D-EN-P
Disconnecting MOVs and
RFI Filter Capacitors The Diode Bus Supply contains protective MOVs, and input filter and
common mode capacitors that are referenced to ground. To prevent damage,
the MOVs should be disconnected from ground if the Bus Supply is
installed on any non-solid grounded distribution system where the
line-to-ground voltages on any phase could exceed 125% of the nominal
line-to-line voltage. To disconnect these devices from ground, remove the
jumpers shown in
Table 1.D . Jumpers can be removed by carefully pulling
the jumper straight out. Solid and non-solid grounded systems are defined
in
Table 1.E .
Table 1.D Jumper Removal
Table 1.E Recommended MOV Configurations
For more information on non-solid grounded system installation, see Wiring
and Grounding Guidelines for Pulse Width Modulated (PWM) AC Drives,
publication
DRIVES-IN001 .
Item Jumper
(1)
(1) Important: Do not remove jumpers if the distribution system is grounded.
Jumper Location (see Figure 1.2 ) Removes Component (see Figure 1.6 )
➎ 12 and GND Control Terminals MOV neutral from Ground
➏ J4 On DFPS Board Capacitors from Ground
Power Source Type
(1)
(1)
It is highly recommended to accurately determine the power source type and then configure appropriately.
MOV/Input Filter
Capacitors
(2)
(2) When MOVs are disconnected, the power system must have its own transient protection to ensure known and
controlled voltages.
Benefits of Correct Power Source
Type Configuration
Solid Grounded
• AC fed, solidly grounded
• DC fed from passive rectifier which
has an AC source and solid ground
Connected • UL compliance
• Reduced electrical noise
• Most stable operation
• EMC compliance
• Reduced voltage stress on
components and motor bearings
Non-Solid Grounded
• AC fed ungrounded
• Impedance grounded
• High resistive ground
• B phase ground
• Regenerative unit (common DC bus
supply and brake)
• DC fed from an active converter
Disconnected • Helps avoid severe equipment
damage when ground fault occurs
!
ATTENTION: To avoid an electric shock hazard, verify that the
voltage on the bus capacitors has discharged before removing/
installing jumpers. Measure the DC bus voltage at the +DC and –
DC output terminals. The voltage must be zero.