Manual

Rockwell Automation Publication 1407-UM001G-EN-P - April 2013 155
Troubleshooting Chapter 7
Table 21 - Reactive Power Control - PF
Symptom Most Likely Cause Diagnostic Action Corrective Action
Power Factor not at PF setpoint PF not enabled Check input tag PF_Ened If not enabled, select appropriate
modes of operation to enable PF
mode
Gain misadjusted Observe response of PF to changes
in PF setpoint
If a response is slow, increase gain
Diode failure Use diode monitor if previously
configured or measure/check diodes
Replace as required
Excitation limiting active Check UEL/OEL active input Correct UEL/OEL configuration or
change operating point
Power Factor unstable/erratic Gain misadjusted Observe response of PF to changes
in PF setpoint
Adjust until a stable response is
observed
Wiring Error Check stability in other control mode
such as Droop
If stable in other mode, see above.
Otherwise, check field output wiring
and VT/CT input wiring
Table 22 - Reactive Power Control - VAR
Symptom Most Likely Cause Diagnostic Action Corrective Action
VARs not at VAR setpoint VAR not enabled Check input tag VAR_Ened If not enabled, select appropriate
modes of operation to enable VAR
mode
Gain misadjusted Observe response of VAR to
changes in VAR setpoint
If a response is slow, increase gain
Diode failure Use diode monitor if previously
configured or measure/check diodes
Replace as required
Excitation limiting active Check UEL/OEL active input Correct UEL/OEL configuration or
change operating point
VARs unstable/erratic Gain misadjusted Observe response of VAR to
changes in VAR setpoint
Adjust until a stable response is
observed
Wiring Error Check stability in other control mode
such as Droop
If stable in other mode, see above.
Otherwise, check field output wiring
and VT/CT input wiring