Yaskawa E7B Drive Bypass - Manual (Page 193)

Diagnostic & Troubleshooting 6 - 13
OV
DC Bus Overvolt
(Flashing)
DC Bus Overvoltage
208-240VAC: Trip point is
≥ 400Vdc
480VAC: Trip point is ≥ 800Vdc
High input voltage at R/L1,
S/L2 and T/L3.
Check the input circuit and
reduce the input power to within
specifications.
Extend the time in C1-02.
The deceleration time is set too
short.
Power factor correction
capacitors are being used on the
input to the Drive.
Remove the power factor correc-
tion capacitors.
OVRD
Emergcy
Override
Emergency Override
Emergency Override is active. Forward or Reverse Emergency
Override input is closed.
When the Forward (H1-0X = 81)
or Reverse (H1-0X = 82)
Emergency Override multi-
function input is closed, the drive
will run at either the B1-14
reference (B1-15 = 0) or the
AUTO reference (B1-15 = 1) and
“OVRD Emergency Override”
will be displayed on the digital
operator.
If the Drive Enable (H1-0X = 6A)
or Bypass Drive Enable
(H1-0X = 70) is programmed, the
emergency override function can
only be activated when the
Enable input is open. If the
Enable input is closed at any time
during emergency override, the
drive will stop.
PRHT
Motor Preheating
Motor Preheating
Motor is preheating.
Motor Preheat 2 input is closed. - - -
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 (Continued)
Digital
Operator Display
Description Cause Corrective Action