Protective And Diagnostic Functions; Fault Detection - YASKAWA Varispeed G7 Series Instruction Manual

Protective and Diagnostic Functions

This section describes the alarm functions of the Inverter. The alarm functions include fault detection,
alarm detection, operation error detection, and autotuning error detection.


Fault Detection

When the Inverter detects a fault, the fault contact output operates, and the Inverter output is shut OFF causing
the motor to coast to a stop. (The stopping method can be selected for some faults, and the selected stopping
method will be used with these faults.) A fault code is displayed on the Digital Operator.
When a fault has occurred, refer to the following table to identify and correct the cause of the fault.
Use one of the following methods to reset the fault before restarting the Inverter:
Set a multi-function contact input (H1-01 to H1-05) to 14 (Fault Reset) and turn ON the fault reset signal.
•
Press the RESET Key on the Digital Operator.
•
Turn the main circuit power supply OFF and then ON again.
•
Display
Overcurrent
OC
The Inverter output current
Over Cur-
exceeded the overcurrent detection
rent
level. (200% of rated current)
Ground Fault
GF
The ground fault current at the
Ground
Inverter output exceeded approxi-
Fault
mately 50% of the Inverter rated
output current.
* The ground fault here is one which occurs in the motor wiring while the motor is running. A ground fault may not be detected in the following cases.
 A ground fault with low resistance which occurs in motor cables or terminals.
 A ground fault occurs when the power is turned ON.
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7
Table 7.1 Fault Displays and Processing
Meaning
• A short-circuit or ground fault
occurred at the Inverter output. (A
short or ground fault can be caused
by motor burn damage, worn insula-
tion, or a damaged cable.)
• The load is too large or the accelera-
tion/deceleration time is too short.
• A special-purpose motor or motor
with a capacity too large for the
Inverter is being used.
• A magnetic contactor was switched
at the Inverter output.
There is a break in the PG wiring.
The PG is wired incorrectly.
Power isn't being supplied to the PG.
• A short-circuit between +V, −V, and
AC terminals occurred.
• Overload in the control circuit termi-
nal.
A ground fault occurred at the Inverter
output. (A ground fault can be caused
by motor burn damage, worn insulation,
or a damaged cable.)
*
• A short-circuit between +V, −V, and
AC terminals occurred.
• Overload in the control circuit termi-
nal.
Probable Causes
Reset the fault after correcting its
cause.
Note: Before turning the power
ON again, make sure that no short-
circuit or ground fault occurs at the
Inverter output.
Fix the broken/disconnected wir-
ing.
Fix the wiring.
Supply power to the PG properly.
• Make sure that incorrect wiring
• Check the resistance and wiring
Reset the fault after correcting its
cause.
Note: Before turning the power
ON again, make sure that no short-
circuit or ground fault occurs at the
Inverter output.
• Make sure that incorrect wiring
• Check the resistance and wiring
Corrective Actions
has not been done.
for the frequency setting potenti-
ometer, etc. (Check that the cur-
rent for terminals +V and –V is
20 mA or less.)
has not been done.
for the frequency setting potenti-
ometer, etc. (Check that the cur-
rent for terminals +V and –V is
20 mA or less.)