YASKAWA Z1000U Technical Manual page 152

5.8 L: Protection Functions
n L2-02: Momentary Power Loss Ride-Thru Time
Sets the length of time that the drive will wait if the control circuit voltage is less than the detection level of the Uv1 after a
momentary power loss before the drive detects a control circuit undervoltage fault (Uv1). This function is applicable when
L2-01 = 1 (Momentary Power Loss Operation Selection = Recover within L2-02). After a power loss, if all of these conditions
are satisfied, the drive detects a Uv1 fault, shuts off the output, and the motor coasts to stop:
• The control circuit voltage is less than the detection level of Uv1.
• The time set in L2-02 is expired.
• The drive does not detect a control power supply voltage fault (Uv2).
• Depending on use conditions, if the time set in L2-02 is long, the drive can detect Uv2 before it detects Uv1. If this is a
problem, decrease the time set in L2-02 to prevent Uv2.
Note: 1. The length of time that the drive can recover after a power loss changes when drive capacity changes.
2. The upper limit of the possible momentary power loss Ride-Thru time changes when drive capacity changes.
No.
L2-02
n
L2-03: Momentary Power Loss Minimum Baseblock Time
Sets the minimum baseblock time when power is restored following a momentary power loss. This determines the time the
drive waits for the residual voltage in the motor to dissipate. Increase this setting if overcurrent or overvoltage occurs at the
beginning of Speed Search, after a power loss, or during DC Injection Braking.
No.
L2-03 Momentary Power Loss Minimum Baseblock Time
u
L3: Stall Prevention
The motor may experience excessive slip because it cannot keep up with the frequency reference when the load is too high or
acceleration and deceleration times are too short. If the motor slips during acceleration, it usually causes an overcurrent fault
(oC), drive overload (oL2), or motor overload (oL1). If the motor slips during deceleration, it can cause excessive regenerative
power to flow back into the DC bus capacitors, and eventually cause the drive to fault out from overvoltage (ov). The Stall
Prevention Function prevents the motor from stalling and while allowing the motor to reach the desired speed without requiring
the user to change the acceleration or deceleration time settings. The Stall Prevention function can be set separately for
acceleration, operating at constant speeds, and deceleration.
n L3-02: Stall Prevention Level during Acceleration
Sets the output current level at which the Stall Prevention during acceleration is activated.
No.
L3-02
<1> The upper limit and default values are determined by parameter L8-38, Carrier Frequency Derating Selection.
• Lower L3-02 if stalling occurs when using a motor that is relatively small compared to the drive.
• Also set parameter L3-03 when operating the motor in the constant power range.
152
Name
Momentary Power Loss Ride-Thru Time
Name
Name
Stall Prevention Level during Acceleration
Setting Range
0.0 to 2.5 s
Setting Range
0.1 to 5.0 s
Setting Range
YASKAWA SIEP YAIZ1D 01C Z1000U HVAC MATRIX Drive Bypass Technical Manual
Default
Default
Determined by o2-04
<1>
0 to 150%
0.5 s
Default
<1>