Manual

7-14 Troubleshooting
7000-UM150I-EN-P – June 2013 7000 “B” Frame
FAULT
MESSAGE
FAULT
CODE
DESCRIPTION
RECOMMENDED ACTIONS
Master CurrentUB
163
The measured and calculated phase
currents in the Master Bridge have
exceeded the value set in Line Current
Unbalance Trip (P108) for the duration set in
Line Current Unbalance Delay (P109).
– Verify that all Current Transformer
connections are connected properly and
that no wires are reversed – Ring-out
wires to verify connections
– Check grounding on CTs
– Ensure that all plugs are firmly
connected in the SCBL
– Check that all input voltages are
balanced
– Verify Parameter settings
– Check the burden resistors
– Verify the Input Capacitor values if
installed
– Verity that there are no open sharing
resistors.
– Verify all Line Thyristors are firing in
Gating Test Mode
– Check the Line Filter Capacitors (for
PWM rectifier drives). Refer to Chapter 6
of the User‟s Manual for detailed
instructions on Testing Filter Capacitors.
Master VoltageUB
160
The measured phase voltages in the Master
Bridge have exceeded the value set in Line
Voltage Unbalance Trip (P271) for the
duration set in Line Voltage Unbalance
Delay (P272).
– CHECK TSN FUSING
– Verify the VSB connections and tap
settings, and check resistance of VSB
board – Megger board to confirm integrity
– Check actual voltage values on the
Operator Interface terminal for each
bridge and the total line voltage
– Check for possible source voltage supply
problems
– Use Multimeter and Oscilloscope to
check voltages on the drive voltage test
points
Motor Current UB
33
The measured current unbalance on the
drive output has exceeded Mtr I UB Trip
(P208) for the duration set in Mtr I UB Delay
(P214).
– Verify the current sensor wiring and
Burden Resistors from the Motor current
sensors
– Verify the HCS power
– Check the Motor Filter Capacitors for
balanced loading on all 3 phases. Refer
to Chapter 6 of the User‟s Manual for
detailed instructions on Testing Filter
Capacitors.
– Investigate the possibility of Motor
winding or cabling problems