Yaskawa E7 Drive User Manual - Manual (Page 115)

Programming 5 - 41
If L2-01= “1: PwrL Ride Thru t”, the Drive restarts without the UV1 fault if power is returned within the time specified in
L2-02, the Momentary Power Loss Ride-thru Time. During the power loss but before the fault trip, the digital operator will
display a UV alarm. If L2-02 is set for a time longer than the control power supply can be sustained, a UV1 fault will not occur
and the Drive restarts upon the return of AC power. The time that the control power supply can be maintained varies with
Drive size. The larger the Drive, the greater the potential ride-thru time.
If L2-01= “2: CPU Power Active”, the Drive ignores L2-02 and attempts a restart as long as the control power supply is still
able to maintain a minimal voltage level. In effect, setting L2-01= “2: CPU Power Active” (factory default) is programming
the Drive for maximum Power Loss Ride-thru. An equivalent setting is L2-01= “1: PwrL Ride Thru t”, with L2-02 set to a
time longer than the control power supply can be maintained after power is lost.
Note: The run command must be held during power loss for any power loss ride-thru capability to be possible. It is for this
reason that 3-wire control is not recommended for use with the Momentary Power Loss function.
L3 Stall Prevention
L3-01 Stall Prevention Selection During Accel
L3-02 Stall Prevention Level During Accel
Setting Range: 0 to 200% of Drive rated output current
Factory Default: 120% of Drive rated output current
The stall prevention during acceleration function adjusts the acceleration time in order to prevent OC fault trips during
acceleration. If L3-01= “0: Disabled”, stall prevention is disabled. If the load is large enough and the acceleration time short
enough the Drive may fault and stop.
If L3-01= “1: General Purpose”, then the standard stall prevention function is enabled. When the output current exceeds the
level set by the L3-02 parameter, the Drive will discontinue accelerating and maintain speed. If, during acceleration, the
output current comes within 15% of the level set by parameter L3-02, the acceleration time is lengthened. Once the output
current level has dropped below the L3-02 level, acceleration will begin again with the acceleration rate reaching the
programmed rate once again 15% below the L3-02 level.
Setting Description
0 Disabled
1 General Purpose (factory default)
2 Intelligent
TM_E7_01_07182008.book Page 41 Wednesday, July 23, 2008 2:35 PM