Rockwell Automation 1336F PLUS II User Manual - Firmware 1.xxx-6.xxx - Manual (Page 105)

Programming 6–23
Feature Select
T1 T2 T3
T1 = Loss of Power
T2 = Line Loss Recognized by Drive
T3 = Power Returned
T4 = Recovery from Line Loss Initiated by Drive
T5 = Minimum Bus Voltage Level, Undervoltage Fault Point
T6 = 500 ms Time Out, Line Loss Fault
T4 T5 T6
[DC Bus Memory]
[Ride Thru Volts]
[Min Bus Volts]
[DC Bus Memory] – [Loss Recover]
[DC Bus Memory] – [Line Loss Volts]
Undervoltage Fault
Line Loss Fault
Power Loss Ride-Thru
Important: The drive has the ability to ride through short
power interruptions. However, power loss ride-thru requires
careful system design to guard against problems associated
with rapid return of the AC line voltage after a line voltage
dip. Consult the factory with your application details before
attempting to program your drive to ride through an AC line
voltage dip of more than 15% below the nominal voltage.
6 parameters are associated with the line loss functionality.
[Line Loss Mode] selects the method of detecting a power
line loss and the response to a line loss.
[Line Loss Volts] adjusts the level at which a line loss is
recognized when [Line Loss Mode] is set to “LoBus>Off” or
“LoBus>Decel.”
[Loss Recover] adjusts the level at which the drive
recognizes the input power has returned when [Line Loss
Mode] is set to “LoBus>Off’ or “LoBus>Decel.”
[Ride Thru Volts] sets the bus voltage that the inertia ride
thru function will attempt to regulate. If [Line Loss Mode] is
set to “LoBus>Decel,” a line loss condition activates the inertia ride thru function. The load is then decelerated such that the energy absorbed from the mechanical
load balances the losses, and bus voltage is maintained.
[Min Bus Volts] sets the bus voltage below which the drive will disable firing of the output devices.
[Line Loss Restart] selects the timing and method of reconnecting the motor after power returns.
Operation when [Line Loss Mode] is set to “LoBus>Off.”
If a power interruption occurs (T1) the drive will continue to operate from stored DC bus energy until the bus voltage drops to the level set by
[DC Bus Memory] – [Line Loss Volts] (T2). At this point, the drive output is turned off and a 500 ms timer is started. One of the following conditions will then occur:
1. The bus voltage will fall below the level set by [Min Bus Volts] (T5) before the timer expires. This will generate a bus Undervoltage Fault if [Low Bus Fault] is
set to ”enabled.”
2. The bus voltage will remain below [DC Bus Memory] – [Loss Recover], but above [Min Bus Voltage] and the timer expires (T6). If [Line Loss Fault] is set to
“enabled,” a Line Loss Fault will be issued.
3. The input power is restored (T3) and the bus voltage rises above [DC Bus Memory] – [Loss Recover] (T4) before the timer expires. This allows the drive to
turn its output on and resume running according to the selection programmed in [Line Loss Restart].
Operation when [Line Loss Mode] is set to “LoBus>Decel.”
Operation in this mode is similar to above, except that the drive will attempt to maintain the bus voltage at the level programmed in [Ride Thru Volts].
If a power interruption occurs (T1) the drive will continue to operate from stored DC bus energy until the bus voltage drops to the level set by
[DC Bus Memory] – [Line Loss Volts] (T2). At this point, the drive will start a 500 ms timer and attempt to regulate the bus voltage at the level set by [Ride Thru
Volts]. One of the following conditions will then occur:
1. The drive is unable to extract enough energy from the mechanical load, and the bus voltage will fall below the level set by [Min Bus Volts] (T5) before the
timer expires. This will generate a bus Undervoltage Fault if [Low Bus Fault] is set to ”enabled.”
2. The bus voltage will be maintained at the level programmed in [Ride Thru Volts] and the timer expires. If [Line Loss Fault] is set to “enabled,” a Line Loss
Fault will be issued.
Important: [Ride Thru Volts] should be set below the level set by [DC Bus Memory] – [Loss Recover], below the level set by [DC Bus Memory] – [Line Loss
Volts], and above the level set by [Min Bus Voltage]. If [Ride Thru Volts] is set above the recovery level, the drive will oscillate in and out of line loss. If [Ride
Thru Volts] is set above the line loss level, as soon as a line loss is detected, the drive will immediately decelerate as quickly as the decel setting allows until
the bus voltage increases to the ride-thru level. If [Ride Thru Volts] is set below [Min Bus Voltage], the bus voltage will be allowed to drop below the minimum
required and the drive output will be turned off.
3. The input power is restored (T3) and the bus voltage rises above [DC Bus Memory] – [Loss Recover] (T4) before the timer expires. The drive will then
accelerate back to the commanded speed using the programmed acceleration rate.
Operation when [Line Loss Mode] is set to “Input>Off” or “Input>Decel.”
When operating in either of these modes, the line loss condition is detected by an external source. The drive is then signaled through the Pulse input that a
loss of power has occurred. Drive operation is the same as when [Line Loss Mode] is set to “LoBus>Off” or “LoBus>Decel,” except for the following: If an inertia
ride-thru is initiated, the drive attempts to regulate the bus at the value in [DC Bus Memory] rather than the value in [Ride Thru Volts].