YASKAWA GA700 Technical Manual page 281

Code Name
Note:
• Detected if PID feedback input is lower than the level set in b5-13 [PID Feedback Loss Detection Lvl] for longer than b5-14 [PID
Feedback Loss Detection Time].
• Perform Fault Reset to clear the fault.
• If detected, the drive will operate the motor according to the stop method set in b5-12 [Feedback Loss Detection Select].
Code Name
GF Ground Fault
Note:
• Detected if a current short to ground exceeded 50% of rated current on the output side of the drive.
• Perform Fault Reset to clear the fault.
Code Name
LF Output Phase Loss
Note:
• Detected if phase loss occurs on the output side of the drive.
• Perform Fault Reset to clear the fault.
• Use L8-07 [Output Phase Loss Protect Select] to enable/disable LF detection.
Code Name
LF2 Output Current Imbalance
YASKAWA ELECTRIC SIEP C710617 01B YASKAWA AC Drive GA700 Technical Manual
Cause
A fault occurred in the feedback input
circuit of the drive.
Cause
The motor is damaged from overheat or
the motor insulation is deteriorated.
The contact with a damaged motor main
circuit cable is creating a short circuit.
The leakage current has become large
due to the stray capacitance of the cable
and the grounding terminal becoming
large.
A drive hardware problem occurred.
Cause
The motor main circuit cable is
disconnected.
Disconnection in the motor coil
winding.
The output terminal screws of the drive
are loose.
The rated output current of the motor
being used is less than 5% of the drive
rated current.
A single-phase motor is being used.
The output transistor in the drive is
damaged.
Cause
Phase loss occurred in the wiring on the
output side of the drive.
The output terminal screws of the drive
are loose.
Balance was lost between the three
phases of the PM motor impedance.
Possible Solution
Replace the board or the entire drive. For
instructions on replacing the control board, contact
Yaskawa or your nearest sales representative.
Possible Solution
Measure the motor insulation resistance, and
replace the motor if there is electrical conduction or
worn insulation.
• Check whether the motor main circuit cable is
damaged, and remove any short circuits.
• Measure the resistance between the motor main
circuit cable and the ground terminal. If there is
electrical conduction, replace the cable.
• If the wiring length of the cable exceeds 100 m,
reduce the carrier frequency.
• Reduce the stray capacitance.
Replace the board or the entire drive. For
instructions on replacing the control board, contact
Yaskawa or your nearest sales representative.
Possible Solution
Correct any disconnected wires in the motor main
circuit cable. Correct any wiring errors in the main
circuit drive input power.
Measure the motor line-to-line resistance and
replace the motor if a coil is disconnected.
Properly tighten the terminals according to the
specified tightening torque.
Check the drive capacity or the motor output to be
applied.
This product cannot operate a single-phase motor.
Replace the control board or the entire drive if the
fault still remains even after all counter-measures
have been taken. For more information on
replacing the control board, contact Yaskawa or
your nearest sales representative.
Possible Solution
Check for any wiring errors or disconnected wires
on the output side of the drive, and fix any
problems.
Properly tighten the terminals according to the
specified tightening torque.
• Measure the line-to-line resistance for each
motor phase, ensuring that resistance is even
between the three phases, and that all wires are
connected properly.
• Replace the motor.
6.4 Fault
6
281