YASKAWA E7 Drive User Manual

Diagnostic & Troubleshooting 6 - 10
UL3
Undertorq Det 1
(Flashing)
Undertorque Detection 1
Drive output current < L6-02 for more than
the time set in L6-03
Motor is underloaded
Ensure the values in
L6-02 and L6-03 are appropriate
Check application/machine status
to eliminate fault
UV
DC Bus Undervolt
(Flashing)
DC Bus Undervoltage
The DC bus voltage is ≤ L2-05
208-240Vac: Trip point is ≤ 190Vdc
480Vac: Trip point is ≤ 380Vdc
Low input voltage at R/L1, S/L2
and T/L3
Check the input circuit and
increase the input power to
within specifications
The acceleration time is set too
short
Extend the time in C1-01
Voltage fluctuation of the input
power is too large
Check the input voltage
UV2
CTL PS Undervolt
Control Power Supply Undervoltage of the
control circuit when running
External load connected pulling
down the Drive power supplies
Cycle power off and on to the
Drive
Repair or replace the Power PCB/
Gate Drive PCB
UV3
MC Answerback
Soft Charge Circuit Fault
The pre-charge contactor opened while the
Drive was running
Contacts on the soft charge
contactor are dirty and the soft
charge contactor does not
function mechanically
Cycle power off and on to the
Drive
Check the condition of the soft
charge contactor
Table 6.2 Alarm Displays and Processing
Digital
Operator Display
Description Cause Corrective Action

YASKAWA E7 Drive Specifications

General

Brand	YASKAWA
Model	E7 Drive
Category	Controller
Language	English