Rockwell Automation Publication 7000-UM202D-EN-P - May 2018 199
Insulation Resistance Test Appendix E
The motor filter capacitors and line filter capacitors (if applicable) may
result in the test results being lower than expected. These capacitors have
internal discharge resistors designed to discharge the capacitors to
ground. If you are uncertain of the test results, disconnect the output
capacitors.
5. Reconnect connections between power circuit and low voltage control.
a. 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.
6. Reconnect the power circuit to the system ground.
Voltage Sensing Boards
a. 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 ACBs.
If you do not connect the ground conductor, the monitored low
voltage signal could then rise up to medium voltage potential, which
is a serious hazard to avoid at all times. Always ensure the ground
conductors on the VSB are securely connected before applying
medium voltage to the drive.
Failure to connect both ground connections on the voltage sensing
board will result in high potential in the low voltage cabinet within
the drive that will damage the drive control, and possible cause injury
or death to personnel.
Grounding Network
b. Reconnect the ground connection on the GN capacitor. The bolt
connection should torque down to 3.4 N•m (30 lb•in). Exceeding
the torque rating of this connection may result in damage to the
capacitor.
Failure to reconnect the GN ground may result in impressing the
neutral voltage offset on the motor cables and stator, which may
result in equipment damage. For drives that did not originally have
the GN connected (or even installed), this is not a concern.
Transient Suppression Network
c. Re-install the fuses on the TSN.
Drive with input/output capacitors disconnected 5k M Ω
Isolation transformer 5k M Ω
Motor 5k M Ω
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 test.
Type of Drive Minimum Insulation Resistance Value
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