YASKAWA A1000 Technical Manual page 278

5.8 L: Protection Functions
KEB Ride-Thru Operation as Long as CPU Has Power, KEB Input Used
Here, L2-01 = 3 and an input terminal is set to issue KEB Ride-Thru (H1- = 65, 66, 7A, 7B). After decelerating for
the time set in parameter L2-10, the drive checks the DC bus voltage and the status of the digital input. If the DC bus
voltage is still below the level set in L2-11 or if the digital input assigned to KEB Ride-Thru is still active, then the drive
continues to decelerate. If the DC bus voltage has risen above L2-11 and the terminal that initiated KEB Rid-Thru is
released, then operation resumes.
Figure 5.99
Power loss shorter than L2-10
Main Power Supply
0 V
KEB Digital Input
DC bus voltage
0 V
Output Frequency
KEB deceleration is
triggered by DC bus voltage
0 Hz
L2-01 = 5
KEB operation ends when the motor has come to a stop, even if the power returns and the digital input terminal that
initiated KEB Ride-Thru is cleared.

KEB Operation Wiring Example
Figure 5.100 shows a wiring example for triggering the KEB Ride-Thru at power loss using an undervoltage relay. If
power loss occurs, the undervoltage relay triggers KEB Ride-Thru at terminal S6 (H1-06 = 65, 66, 7A, 7B). Note that an
additional dynamic braking option is required if System KEB Ride-Thru 1 is used.
Note: 1. Make sure the Run command is not switched off during momentary power loss. If the Run command is shut off, the drive will not
accelerate back to speed when the power is restored.
2. A dynamic braking option is required in order to use System KEB 1 (L2-29 = 2).
Figure 5.100
278
Power Loss
L2-11 (Desired DC Bus Voltage)
L2-05 (Uv Detection Level)
KEB restart after
L2-10 (Minimum KEB
L2-02 has passed
Operation Time)
Figure 5.99 KEB Operation Using L2-10 and KEB Input
R/L1
L1
S/L2
L2
T/L3
L3
UV Detection
Relay
S6 - KEB command 1 or 2
S1 - Start command
SC
Figure 5.100 KEB Function Wiring Example
YASKAWA ELECTRIC SIEP C710616 27G YASKAWA AC Drive A1000 Technical Manual
0 V
0 V
KEB deceleration is
triggered by DC bus voltage
0 Hz
Braking
Required for System KEB
Resistor
Ride-Thru 1 only (L2-29 = 2)
B1 B2
U/T1
V/T2
W/T3
Power loss longer than L2-10
Power Loss
L2-11 (Desired DC Bus Voltage)
L2-05 (Uv Detection Level)
L2-10 (Min.
KEB KEB restart after
Operation L2-02 has passed
Time)
M