System Concepts; Auxiliary Power Supply Selection; Shell Diagram - Danfoss VLT ISD 510 Design Manual

System Integration
electronic devices, use voltage-dependent resistors
(varistors) to attenuate transients.

4.5 System Concepts

4.5.1 Auxiliary Power Supply Selection

4.5.1.1 Shell Diagram

4 4
The allowed number of servo drives on a hybrid line is
limited by the fact that voltage drops occur on the hybrid
cable. These voltage drops involve the auxiliary voltage
(24/48 V DC). The voltage drops on the cable depend on
the power consumption of the servo drives on the hybrid
line. The differences in power consumption are due to
servo drives with integrated holding brake, servo drives
without integrated holding brake, and ISD standard and
ISD advanced servo drive versions.
The number of ISD servo drives connected on 1 line
depends on several conditions. The most important
conditions are:
•
Power required by the servo drives on the
auxiliary supply
•
Auxiliary voltage
•
Cable length
The shell diagram is only calculated for servo drives
without sensors connected (8–9.6 W) and only with a feed-
in cable length of 10 m. The 1
consumption of each servo drive is set to 8 W. Then the
number of servo drives with brake (9.6 W) is increased
step-by-step. The servo drives with brake must be
connected at the beginning of the output line to lower the
voltage drop for all servo drives.
44
®
VLT Integrated Servo Drive ISD
st
step is that the power
Danfoss A/S © 08/2017 All rights reserved.
®
510 System
100
90
80
70
60
50
4
40
30
20
10
0
0 2 4 6
1 0 ISD servo drives with brake
2 3 ISD servo drives with brake
3 6 ISD servo drives with brake
4 Example 1
Illustration 4.6 24 V and 10 m Feed-in Cable
Example I: 7 servo drives are possible with a cable length
of 38 m, and 6 of them can be equipped with a brake.
The graphs are very close together because there is only a
slight difference between the AUX power consumption of
the servo drives with and without brake. The graphs are
calculated with the servo drives with brake connected at
the beginning of the line.
1
2
3
8 10 12 14
n
MG36C102