Yaskawa AC Drive Z1000 Bypass Technical Manual - Manual (Page 234)

The electrical thermal protection characteristics
and motor overload characteristics do not match
• Check the motor characteristics.
• Correct the type of motor protection that has been selected (L1-01).
• Install an external thermal relay.
The electrical thermal relay is operating at the
wrong level
• Check the current rating listed on the motor nameplate.
• Check the value set for the motor rated current (E2-01).
Motor overheated by overexcitation operation
• Overexcitation increases the motor loss and the motor temperature. Excessive duration of
overexcitation may cause motor damage. Prevent excessive overexcitation operation or apply
proper cooling to the motor.
• Reduce the excitation deceleration gain (n3-13).
• Set L3-04 (Stall Prevention during Deceleration) to a value other than 4.
Parameters related to Speed Search are set
incorrectly
• Check values set to Speed Search related parameters.
• Adjust the Speed Search current and Speed Search deceleration times (b3-02 and b3-03
respectively).
Output current fluctuation due to input phase loss Check the power supply for phase loss.
HOA Keypad Display Fault Name
oL2
Drive Overload
The thermal sensor of the drive triggered overload protection.
Cause Possible Solution
Load is too heavy Reduce the load.
Acceleration or deceleration time is too short Increase the settings for the acceleration and deceleration times (C1-01 and C1-02).
The output voltage is too high
• Set E1-03 to a V/f pattern matching the application.
• Do not lower E1-08 and E1-10 excessively. This reduces load tolerance at low speeds.
Drive capacity is too small Replace the drive with a larger model.
Overload occurred when operating at low speeds
• Reduce the load when operating at low speeds.
• Replace the drive with a model that is one frame size larger.
• Lower the carrier frequency (C6-02).
Excessive torque compensation Reduce the torque compensation gain in parameter C4-01 until there is no speed loss but less current.
Parameters related to Speed Search are set
incorrectly
• Check the settings for all Speed Search related parameters.
• Adjust the current used during Speed Search (b3-03) and the Speed Search deceleration time
(b3-02).
• After Auto-Tuning, set b3-24 to 1 to enable Speed Estimation Speed Search.
Output current fluctuation due to input phase loss Check the power supply for phase loss.
HOA Keypad Display Fault Name
oL3
Overtorque Detection 1
The current has exceeded the value set for torque detection (L6-02) for longer than the allowable time
(L6-03).
Cause Possible Solution
Parameter settings are not appropriate for the load Check L6-02 and L6-03 settings.
Fault on the machine side (e.g., machine is locked
up)
Check the status of the load. Remove the cause of the fault.
HOA Keypad Display Fault Name
oL7
High Slip Braking oL
The output frequency stayed constant for longer than the time set to n3-04 during High Slip Braking.
Cause Possible Solution
Excessive load inertia
Reduce deceleration time in parameter C1-02 for applications that do not use High Slip Braking.
Motor is driven by the load
Something on the load side is restricting
deceleration
The overload time during High Slip Braking is too
short
• Increase parameter n3-04 (High-slip Braking Overload Time).
• Install a thermal relay and increase the setting of n3-04 to maximum value.
6.4 Fault Detection
234 YASKAWA ELECTRIC SIEP YAIZ1B 01D YASKAWA AC Drive – Z1000 Bypass Technical Manual