Delta Electronics VFD-EL Power Supply User Manual


 
Chapter 4 Parameters|
4-78 Revision August 2008, 2ELE, V1.02
DC Brake during Start-up is used for loads that may move before the AC drive starts, such as
fans and pumps. Under such circumstances, DC Brake can be used to hold the load in
position before setting it in motion.
DC Brake during stopping is used to shorten the stopping time and also to hold a stopped load
in position. For high inertia loads, a brake resistor for dynamic brake may also be needed for
fast decelerations.
08.04 Momentary Power Loss Operation Selection
Factory Setting: 0
Settings 0 Operation stops (coast to stop) after momentary power loss.
1 Operation continues after momentary power loss, speed search
starts with the Master Frequency reference value.
2 Operation continues after momentary power loss, speed search
starts with the minimum frequency.
This parameter determines the operation mode when the AC motor drive restarts from a
momentary power loss.
08.05 Maximum Allowable Power Loss Time Unit: 0.1
Settings 0.1 to 5.0 sec Factory Setting: 2.0
If the duration of a power loss is less than this parameter setting, the AC motor drive will
resume operation. If it exceeds the Maximum Allowable Power Loss Time, the AC motor drive
output is then turned off (coast stop).
The selected operation after power loss in Pr.08.04 is only executed when the maximum
allowable power loss time is 5 seconds and the AC motor drive displays “Lu”.
But if the AC motor drive is powered off due to overload, even if the maximum allowable power
loss time is 5 seconds, the operation mode as set in Pr.08.04 is not executed. In that case it
starts up normally.
08.06 Base Block Speed Search
Factory Setting: 1
Settings 0 Disable
1 Speed search starts with last frequency command
2 Speed search starts with minimum output frequency (Pr.01.05)
This parameter determines the AC motor drive restart method after External Base Block is
enabled.