Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive (A Frame) - ForGe Control - Manual (Page 185)

Rockwell Automation Publication 7000A-UM200C-EN-P - June 2014 185
Meggering Appendix E
Reconnecting Connections between Power Circuit and
Low Voltage Control
Reconnect the ribbon cables “J1”, J2” and “J3” in all the VSBs. Do not cross the
cable connections. Mixing the feedback cables may result in serious damage to the
drive.
Reconnect the Power Circuit to the System Ground
Voltage Sensing Boards
Securely reconnect the two ground conductors on the VSBs.
The two ground connections on the VSB provide a reference point for the VSB
and enable the low voltage signal to be fed to the SCBs. If the ground conductor
was not connected, the monitored low voltage signal could then rise up to
medium voltage potential which is a serious hazard that must be avoided at all
times. You must always ensure the ground conductors on the VSB are securely
connected before applying medium voltage to the drive.
Output Grounding Network
Reconnect the ground connection on the OGN capacitor. The bolt connection
should be torque down to 3.4 N•m (30 lb•in). Exceeding the torque rating of this
connection may result in damage to the capacitor.
IMPORTANT Humidity and dirty standoff insulators may also cause leakage to ground
because of tracking. You may have to clean a 'dirty' drive prior to commencing
the Megger test.
ATTENTION: Failure to connect both ground connections on the voltage
sensing board will result in high potential in the Low Voltage cabinet within the
drive which will result in damage to the drive control and possible injury or
death to personnel.
ATTENTION: Failure to reconnect the OGN ground may result in the neutral
voltage offset being impressed on the motor cables and stator, which may
result in equipment damage. For drives that did not originally have the OGN
connected (or even installed), this is not a concern.