Yaskawa Z1000U - Manual (Page 126)

No. Name Setting Range Default
L2-01 Momentary Power Loss Operation Selection 0 to 2 0
Setting 0: Disabled
If a momentary power loss occurs, a power supply frequency fault (Fdv) is detected and the drive output is turned OFF. The
motor coasts to stop.
Setting 1: Recover within L2-02
When a momentary power loss occurs, the drive output will be shut off. If the power returns within the time set to parameter
L2-02, the drive will perform Speed Search and attempt to resume operation. If power does not return within this time, it will
trigger a Uv1 fault.
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 an Fdv fault.
Notes on Settings 1 and 2:
• “Uv” flashes on the operator while the drive attempts to recover from a momentary power loss. A fault signal is not output
at this time.
• When using a magnetic contactor between the motor and the drive, keep the magnetic contactor closed while the drive
attempts to restart with Speed Search.
n L2-02: Momentary Power Loss Ride-Thru Time
Sets the maximum time allowed to ride through a power loss. If power loss operation exceeds this time, the drive will attempt
to accelerate back to the frequency reference. This parameter is valid when L2-01 = 1.
Note: The amount of time the drive is capable of recovering after a power loss is determined by the capacity of the drive. Drive capacity determines
the upper limit for L2-02.
No. Name Setting Range Default
L2-02 Momentary Power Loss Ride-Thru Time 0.0 to 2.5 s 0.5 s
n L4-05: Frequency Reference Loss Detection Selection
The drive can detect a loss of an analog frequency reference from input A1, A2, or A3. Frequency reference loss is detected
when the frequency reference drops below 10% of the reference or below 5% of the maximum output frequency within 400
ms.
100%
400 ms
Analog
frequency
reference
Loss of
Reference
output
time
10%
ON OFF
Figure 4.27 Loss of Reference Function
Set H2-01 or H2-02 to C for a digital output to trigger when frequency reference loss occurs.
Parameter L4-05 selects the operation when a frequency reference loss is detected.
No. Name Setting Range Default
L4-05 Frequency Reference Loss Detection Selection 0, 1 1
Setting 0: Stop
Drive follows the frequency reference (which is no longer present) and stops the motor.
Setting 1: Continue Operation with Reduced Frequency Reference
The drive will continue operation at the percent of the previous frequency value set to parameter L4-06. When the external
frequency reference value is restored, the operation is continued with the frequency reference.
4.7 Basic Drive Setup Adjustments
126 YASKAWA ELECTRIC TOEP C710636 10B Z1000U HVAC MATRIX Drive User Manual