L2: Momentary Power Loss Ride-Thru - YASKAWA A1000 Series Technical Manual

◆ L2: Momentary Power Loss Ride-Thru

L2-01: Momentary Power Loss Operation Selection
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When a momentary power loss occurs (DC bus voltage falls below the level set in L2-05), the drive can be set to
automatically return to the operation it was performing when the power went out based on certain conditions.
No.
L2-01
Setting 0: Disabled (default)
If power is not restored within 15 ms, a Uv1 fault will result and the drive will stop the motor. The motor coasts to stop.
Setting 1: Recover within L2-02
When a momentary power loss occurs, the drive output will be shut off. Should the power return within the time set to
parameter L2-02, th e drive will perform Speed Search and attempt to resume operation. If power is not restored within
this time (i.e., DC bus voltage level remains below Uv1 detection level L2-05), then a Uv1 fault is triggered.
Setting 2: Recover as long as CPU has power
When a momentary power loss occurs, the drive output will be shut off. Should the power return as long as the drive
control circuit has power, th e drive will attempt to perform Speed Search and resume the operation. A Uv1 fault is not
triggered.
Setting 3: KEB Ride-Thru operation within L2-02
The drive decelerates using regenerative energy from the motor until the time set in L2-02 has expired. It then tries to
accelerate back to the frequency reference. If the power does not returned within the time set in L2-02, an Uv1 fault is
triggered and the drive output shuts off. The type of KEB operation is determined by the setting of L2-29.
Setting 4: KEB Ride-Thru as long as CPU has power
The drive decelerates using regenerative energy from the motor until the power returns and then restarts. If the motor has
come to a stop before, the power returns. If the drive control power gets lost, the drive output will shut off. A Uv1 fault is
not triggered. The type of KEB operation is determined by the setting of L2-29.
Setting 5: Ramp to stop with KEB deceleration
The drive ramps to stop using the regenerative energy from the motor. Even if the power is restored, the drive will
continue decelerating until it brings the motor to a complete stop. The type of KEB operation is determined by the setting
of parameter L2-29. Note that if an input terminal set for KEB 1 (H1-
decelerating, then it will accelerate back up to speed when the input is released.
Notes on Settings 1 through 5
• "Uv" will flash on the operator while the drive is attempting to recover from a momentary power loss. A fault signal is
not output at this time.
• A Momentary Power Loss Unit is available to allow for a longer momentary power loss ride through time in the drive
model CIMR-A 2A0004 through 2A0056 and CIMR-A 4A0002 through 4A0031. This option makes it possible to
continue running after up to two seconds of power loss.
• When a magnetic contactor between motor and drive is used, be sure that the magnetic contactor remains closed as
long as the drive performs KEB operation or attempts to restart with Speed Search.
• Make sure the Run command is kept active during KEB operation. Otherwise the drive cannot accelerate back to the
frequency reference when the power returns.
• When L2-01 is set to 3, 4, or 5, KEB Ride-Thru will be executed as specified in L2-29.
KEB Ride-Thru Function
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When power loss is detected, the Kinetic Energy Backup Ride-Thru function (KEB Ride-Thru) decelerates the motor and
uses regenerative energy to keep the main circuit operating. Despite power loss, the drive output is not interrupted.
For applications driven by a single drive, choose between Single Drive KEB Ride-Thru 1 and 2 (L2-29 = 0 or 1).
For applications where multiple drives have to perform KEB operation while keeping a certain speed ratio (such as
textile machinery), select between System KEB Ride-Thru 1 and 2, (L2-29 = 2 or 3).
YASKAWA ELECTRIC SIEP C710616 27C YASKAWA AC Drive A1000 Technical Manual
Name
Momentary Power Loss Operation Selection
5.8 L: Protection Functions
Setting Range
0 to 5
= 65, 66) is triggered while the drive is
Default
0
5
249