YASKAWA A1000 HHP Programming Manual page 135

Setting 2: Recover as long as CPU has power
When a momentary power loss occurs, the drive output will be shut off. If the power returns and the drive control circuit has
power, the drive will attempt to perform Speed Search and resume the operation. This will not trigger a Uv1 fault.
Setting 3: Kinetic Energy Backup (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 return within the time set to L2-02, it will trigger a Uv1 fault and the
drive output will shut off.
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 comes
to a stop before the power returns, the drive loses control power and the drive output shuts off. A Uv1 fault is not triggered.
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
to decelerate until the motor comes to a complete stop. If an input terminal set for KEB 1 (H1-oo = 65, 66) is triggered while
the drive is decelerating, 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 models
CIMR-Ao2A0004 to 2A0056 and 4A0002 to 4A0031. This option makes it possible to continue running the drive after up
to two seconds of power loss.
• When using a magnetic contactor between the motor and the drive, keep the magnetic contactor closed as long as the drive
performs KEB operation or attempts to restart with Speed Search.
• Keep the Run command active during KEB operation or the drive cannot accelerate back to the frequency reference when
the power returns.
n KEB Ride-Thru Function
When the drive detects a power loss, 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.
Single Drive KEB Ride-Thru 1
After KEB Ride-Thru begins, the drive uses regenerative energy from the motor to keep the DC bus voltage at the level set
to L2-11 while adjusting the rate of deceleration.
n KEB Ride-Thru Start
KEB operation is triggered independently of the selected KEB operation mode. When the KEB function is selected as the
function to be executed when power loss operation occurs (L2-01 = 3, 4, or 5), then KEB Ride-Thru will be activated if one
of the following conditions becomes true:
• A digital input programmed for H1-oo = 65 or 66 is activated. This will start the KEB operation.
• The DC bus voltage fell below the level specified in L2-05.
When using a digital input to trigger KEB operation and the device controlling the input acts relatively slow, set a minimum
KEB operation time in parameter L2-10. In the example below, the DC bus voltage triggers KEB operation and a digital input
triggers the Hold command.
YASKAWA ELECTRIC SIEP YEAHHP 01B YASKAWA AC Drive – A1000 HHP Programming Manual
1.8 L: Protection Functions
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