Rockwell Automation 1336 8A-48A Fiber Industry - Manual (Page 94)

5–28 Programming
Power Loss Ride-Thru
The 1336 plus has the ability to ride through short power
interruptions. On loss of input power to the drive, the drive offers
two methods of operation.
Diagram 1
With the Line Loss Fault parameter disabled, if a power
interruption occurs (T1) the drive will continue to operate off
stored DC bus energy until bus voltage drops to 85% of its
nominal value (T2). At this point, the drive output is shut off,
allowing the DC bus to discharge more slowly. The drive will
retain its logic and operating status as long as bus voltage is
above the absolute minimum bus voltage (refer to Appendix). If
bus voltage should fall below this level (T5), the drive will trip and
Undervolt Fault will be displayed. If input power is restored before
this minimum is reached (T3) and bus voltage rises above the
85% level (T4), the drive will restore output power to the motor
and resume running.
Diagram 2
With the Line Loss Fault parameter enabled, if input power is lost
(T1) the drive will continue to operate until the bus voltage falls
below 85% of nominal (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 minimum before the time ex-
pires (T6). This will generate an Undervolt Fault.
2. The bus voltage will remain below 85% but above minimum
and the timer expires (T5). This will generate a Line Loss Fault.
3. The input power is restored (T3) and the bus voltage rises
above the 85% level before the timer expires (T4). This allows
the drive to turn its output on and resume running.
Output DIAGRAM 1
T1
T1 = Loss of Power
T2 = Bus Level at 85% of Nominal, Outputs Shut Off
T3 = Power Returned
T4 = Outputs Turned On
T5 = Minimum Bus Voltage Level, Undervoltage Fault Point
T2 T4 T5 T3
Logic
Output Off
100% V
BUS
85% V
BUS
Minimum V
BUS
Undervoltage Fault
(depends on [Low Bus Fault])
Output
T1
T1 = Loss of Power
T2 = Bus Level at 85% of Nominal, Outputs Shut Off
T3 = Power Returned
T4 = Outputs Turned On
T5 = 500mS Time Out, Line Loss Fault
T6 = Minimum Bus Voltage Level, Undervoltage Fault Point
T2 T4 T6
T5
T3
Logic
Output Off
100% V
BUS
85% V
BUS
Minimum V
BUS
Undervoltage Fault
(depends on [Low Bus Fault])
Line Loss Fault
DIAGRAM 2
Faults