Emerson E300 Series Design Manual page 422

Safety Product Mechanical
information information installation
Backup Supply Mode for frame size 06 drives and smaller: LV Supply Mode Enable (O12) = 1
Backup supply mode is intended to provide a smooth transition, without disabling the drive, from a high voltage a.c. supply to a low voltage d.c.
backup supply. It is necessary to disable the drive for the transition back to the high voltage a.c. supply. The following diagram is a simple
representation of the power circuit required. This does not include the necessary circuit protection components or possible battery charger, etc.
High
voltage a.c.
supply
Low voltage
d.c. backup
supply
The diagram below shows the state of Under Voltage (L19), the control signal to the external contactor (Under Voltage Contactor Close Output
(O15)) and Active Supply (O09). When LV Supply Mode Enable (O12) is set to one the maximum applied to Low Under Voltage Threshold (O14)
prevents this from being increased above Standard Under Voltage Threshold (O11) / 1.1 so that the 5 % hysteresis band on the low under-voltage
threshold does not overlap the standard under-voltage threshold.
Figure 8-37 Backup Supply Mode
Upper threshold based on
Standard Under - voltage
Threshold(O11)
Lower threshold based on
Low Under-voltage
Threshold (O14)
1. If the D.C. Bus Voltage (J65) is below the Lower Threshold the drive is in the under-voltage state and the internal charge system is active to limit
the charging current either from the low voltage d.c. backup supply or the high voltage a.c. supply. Under Voltage Contactor Close Output (O15) =
1, and so it is possible for the high voltage a.c. supply to charge the d.c. link.
2. If the D.C. Bus Voltage (J65) is above the Lower Threshold, but below the Upper Threshold, there are two possible states depending on whether
the Final drive enable is 0 or 1. If Final drive enable = 0 then Under Voltage (L19) = 1, the internal charge system is active and Under Voltage
System Contactor Closed (O16) = 1, so that the d.c. link can be charged by the high voltage a.c. supply. If Final drive enable = 1 then Under
Voltage (L19) = 0 and the internal charge system is inactive so that the drive can run from the low voltage d.c. backup supply. Under Voltage
Contactor Close Output (O15) = 0, so that it is not possible for the high voltage a.c. supply to charge the d.c. link.
3. If the D.c. Bus Voltage (J65) is above the Upper Threshold then Under Voltage (L19) = 0 and Under Voltage System Contactor Closed (O16) = 1,
so the drive can run from the high voltage a.c. supply.
4. If the D.c. Bus Voltage (J65) subsequently falls below the Upper Threshold and the Final drive enable = 1, the drive can continue to run, but
Under Voltage System Contactor Closed (O16) is set to 0 to open the high voltage a.c. supply contactor. The d.c. link voltage will fall until it
reaches the low voltage d.c. backup supply level. This gives a smooth changeover to the backup supply without stopping the motor.
422
Electrical Getting
User Menu A Commissioning
installation started
K1
K1
Backup supply mode for frame size 08 drives and larger
Final drive
enable
Under-voltage
System Contactor
Under Voltage
Close (O15) = 0
Active (L19) = 1
Backup supply mode states for frame size 08 drives and larger
Advanced
Parameters
Drive with backup supply
Digital output routed from
Under-voltage System
Contactor Close(O15)
+24V
Digital input routed to Under-
voltage System Contactor
Closed (O16)
Final drive
enable
Under-voltage System
Contactor Close (O15) = 1
Under-voltage System
Contactor Close (O15) = 1
Diagnostics Optimization CT MODBUS RTU Technical Data
Active
Supply
(O09) = 0
D.c. Link
Voltage
Active
(J65)
Supply
(O09) = 1
Active
Supply
(O09) = 1
E300 Design Guide
Issue Number: 1