20
Rockwell Automation Publication 20P-TG001C-EN-P - February 2018
Chapter 2
Component Test Procedures
Troubleshoot an AC
Undervoltage Fault
If one of the following occurs, measure the AC line input signals as directed in
these steps:
• The drive faults with an AC Undervoltage Fault (F4)
• The value of parameter 466 [AC Line Voltage] does not equal the
expected incoming AC line voltage
1. Read the General Safety Precautions on page
2. Remove the protective covers from the drive (see page
3. Use a voltmeter to measure the voltage at terminals U, V, and W of the
drive. If an AC input contactor is used, the voltage must be measured on
both the input and output sides of the contactor.
If any of the voltage measurements is incorrect or missing, remove
incoming AC power and verify the wiring to the drive and the power
supply source and correct any problems.
4. Using a voltmeter, measure the combined voltages of the AC lines on the
following testpoints on the control board (all waveforms have a 2.5V
offset). See
on page
on page
for location of
the testpoints. See
on page
for a schematic diagram.
ATTENTION:
Servicing energized equipment can be hazardous. Severe
injury or death can result from electrical shock, burn, or unintended
actuation of controlled equipment. Follow Safety related practices of NFPA
70E, ELECTRICAL SAFETY FOR EMPLOYEE WORKPLACES.
Table 1 - Combined AC Line Input Signal Testpoints
Incoming AC
Line Voltage
Phases
Measure from
Testpoint
… To Testpoint
Peak to Peak
Measurement
RMS
Measurement
240V AC
V and U
XY22
…
XY18
1.42V AC
0.500V
V and W
XY21
…
XY18
480V AC
V and U
XY22
…
XY18
2.95V AC
1.040V
V and W
XY21
…
XY18
575V AC
V and U
XY22
…
XY18
2.85V AC
1.007V
V and W
XY21
…
XY18
690V AC
V and U
XY22
…
XY18
3.45V AC
1.220V
V and W
XY21
…
XY18
