Danfoss VLT AutomationDrive FC 301 Series Design Manual page 150

Electrical Installation
L1
T1
Enclosure type
C1
C1
C2
Figure 9.47 Terminal Connections for C1, C2
9.6.3 Load Sharing
The DC bus terminal is used for DC backup, with the
intermediate circuit being supplied from an external
9 9
source. It uses terminals 88 and 89.
The connection cable must be shielded and the max.
length from the adjustable frequency drive to the DC bar
is limited to 82 ft [25 m].
Load sharing enables the linking of the DC intermediate
circuits of several adjustable frequency drives.
CAUTION
Note that voltages up to 1099 V DC may occur on the
terminals.
Load sharing calls for extra equipment and safety
considerations.
CAUTION
Note that line power disconnect may not isolate the
adjustable frequency drive due to DC link connection.
148
Design Guide
L2 L3
T2 T3
Type
Kraus&Naimer KG100 T303
Kraus&Naimer KG105 T303
Kraus&Naimer KG160 T303
Rev. 2014-04-04 All rights reserved.
9.6.4 Brake Resistor
13
The connection cable to the brake resistor must be
shielded and the max. length from adjustable frequency
drive to the DC bar is limited to 82 feet [25 m].
1. Connect the shield by means of cable clamps to
the conductive backplate on the adjustable
14
frequency drive and to the metal cabinet of the
brake resistor.
2. Size the brake cable cross-section to match the
brake torque.
Terminals 81 and 82 are brake resistor terminals.
NOTICE!
If a short circuit in the brake IGBT occurs, prevent power
dissipation in the brake resistor by using a line switch or
contactor to disconnect the line power from the
adjustable frequency drive. Only the adjustable
frequency drive should control the contactor.
CAUTION
Note that voltages up to 1,099 V DC, depending on the
supply voltage, may occur on the terminals.
9.6.5 PC Software
The PC is connected via a standard (host/device) USB
cable, or via the RS-485 interface.
USB is a serial bus utilizing four shielded wires with
Ground pin 4 connected to the shield in the PC USB port.
When connecting the PC to an adjustable frequency drive
through the USB cable, there is a potential risk of
damaging the PC USB host controller. All standard PCs are
manufactured without galvanic isolation in the USB port.
Any ground potential difference caused by not following
the recommendations described in AC Line Input
Connection in the Instruction Manual can damage the USB
host controller through the shield of the USB cable.
It is recommended to use a USB isolator with galvanic
isolation to protect the PC USB host controller from
ground potential differences when connecting the PC to
an adjustable frequency drive through a USB cable.
MG33BF22