YASKAWA FP65U T Series Installation & Primary Operation page 90

20 Troubleshooting
Code Name
LWL Low Water Level
NMS Setpoint Not Met
nSE Node Setup Error
oC Overcurrent
90
Causes
• The digital input terminal set to H1-xx = BB
[MFDI Function Selection = Low Water Level]
activated or is defective.
• The digital input terminal set to H1-xx = 1BB [!
Low Water Level] deactivated or is defective.
The feedback deviates from the setpoint at a level
more than Y1-15 [Maximum Setpoint Difference] for
the time set in Y1-16 [Not Maintaining Setpoint
Time].
The drive received a Run command while the Node
Setup function was active.
The load is too large.
Overheating caused damage to the motor or the motor
insulation is not satisfactory.
The motor main circuit cable is contacting ground to
make a short circuit.
A short circuit or ground fault on the drive output
side caused damage to the output transistor of the
drive.
The acceleration time is too short.
The drive is trying to operate a specialized motor or a
motor that is larger than the maximum applicable
motor output of the drive.
A magnetic contactor was switched at the output.
The V/f pattern settings are incorrect.
The torque compensation gain is too large.
Electrical interference caused a problem.
The gain during overexcitation operation is too large.
The drive received a Run command while the motor
was coasting.
The motor code setting is incorrect for PM Control
Methods.
The current flowing in the motor is more than the
value set in L8-27 [Overcurrent Detection Gain] for
PM Control Methods.
The control method is set incorrectly for the motor.
The motor main circuit cable is too long.
YASKAWA TOEPC7106171GA FP605 Drive Installation & Primary Operation
Possible Solutions
• Increase the water level.
• Adjust the terminal set to H1-xx = BB or 1BB.
• Examine for a blocked impeller, over cycling, or broken pipe.
• Set Y1-15 and Y1-16 correctly.
Stop the drive when the Node Setup function is in use.
• Measure the current flowing into the motor.
• Replace the drive with a larger capacity model if the current
value is more than the drive rated current.
• Decrease the load or replace with a larger drive to prevent
sudden changes in the current level.
Measure the motor insulation resistance, and replace the motor if
there is electrical conduction or unserviceable insulation.
• Examine the motor main circuit cable for damage, and repair
short circuits.
• Measure the resistance between the motor main circuit cable and
the ground terminal. If there is electrical conduction, replace the
cable.
• Make sure that there is not a short circuit in terminals - and
terminals U/T1, V/T2, and W/T3.
• If there is a short circuit, contact Yaskawa or your nearest sales
representative.
• Calculate the torque necessary during acceleration related to the
load inertia and the specified acceleration time.
• Increase the values set in C1-01 or C1-03 [Acceleration Times]
to get the necessary torque.
• Increase the values set in C2-01 to C2-04 [S-Curve
Characteristics] to get the necessary torque.
• Replace the drive with a larger capacity model.
• Examine the motor nameplate, the motor, and the drive to make
sure that the drive rated current is larger than the motor rated
current.
• Replace the drive with a larger capacity model.
Set the operation sequence to not turn ON or OFF the magnetic
contactor while the drive is outputting voltage.
• Examine the ratios between the V/f pattern frequency and
voltage. Decrease the voltage if it is too high compared to the
frequency.
• Adjust E1-04 to E1-10 [V/f Pattern Parameters]. For motor 2,
adjust E3-04 to E3-10.
Decrease the value set in C4-01 [Torque Compensation Gain] to
make sure that the motor does not stall.
Examine the control circuit lines, main circuit lines, and ground
wiring, and decrease the effects of electrical interference.
• Find the time when the fault occurs.
• If the fault occurs at the same time as overexcitation operation,
decrease the value set in n3-13 [OverexcitationBraking (OEB)
Gain] and consider the motor flux saturation.
• Examine the sequence and input the Run command after the
motor fully stops.
• Set b3-01 = 1 [Speed Search at Start Selection = Enabled] or set
H1-xx = 61, 62 [Speed Search from Fmax or Fref] to input speed
search commands from the MFDI terminals.
• Enter the correct motor code to E5-01 [PM Motor Code
Selection] as specified by the PM motor.
• For specialized motors, refer to the motor test report and set E5-
xx [PM Motor Settings] correctly.
Correct the value set in L8-27.
Set A1-02 [Control Method Selection] correctly.
Replace the drive with a larger capacity model.