Load Share Overview - Danfoss VLT AutomationDrive FC 302 Design Manual

Product Features

5.5 Load Share Overview

Load share is a feature that allows the connection of DC circuits of several drives, creating a multiple-drive system to run 1
mechanical load. Load share provides the following benefits:
Energy savings
A motor running in regenerative mode can supply drives that are running in motoring mode.
Reduced need for spare parts
Usually, only 1 brake resistor is needed for the entire drive system instead of 1 brake resistor for per drive.
Power back-up
If there is mains failure, all linked drives can be supplied through the DC link from a back-up. The application can continue
running or go though a controlled shutdown process.
Preconditions
The following preconditions must be met before load sharing is considered:
•
The drive must be equipped with load sharing terminals.
•
Product series must be the same. Use only VLT
FC 302 drives.
•
Drives must be placed physically close to one another to allow the wiring between them to be no longer than
25 m (82 ft).
•
Drives must have the same voltage rating.
•
When adding a brake resistor in a load sharing configuration, all drives must be equipped with a brake chopper.
•
Fuses must be added to load share terminals.
For a diagram of a load share application in which best practices are applied, see Illustration 5.9.
3x Class L-800 A
380 V
Common mains
disconnect switch
Illustration 5.9 Diagram of a Load Share Application Where Best Practices are Applied
MG38C202
Design Guide
®
AutomationDrive FC 302 drives with other VLT
2x aR-1000 A
315 kW
91 96
92 97
93 98
82 81
3x 1.2%
Danfoss A/S © 01/2018 All rights reserved.
2x aR-1500 A
500 kW
91 96
M
92 97
93 98
82 81
3x 1.2%
3x Class L-1200 A
®
AutomationDrive
DC connecting point for
additional drives in the
load sharing application
M
Mains connecting point for
additional drives in the
load sharing application
27
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