X20 system modules • Motor controllers • X20SM1436
2026
X20 system User's Manual 3.10
4.25.7.13 Protection
The power supply line should be protected by a circuit breaker or a fuse. In general, dimensioning the supply line
and overcurrent protection depends on the structure of the power supply (modules can be connected individually
or in groups).
Information:
The effective current for the power supply depends on the load but is always less than the motor
current. Make sure the maximum nominal current of 10 A is not exceeded on the power supply terminals
of the power unit.
When choosing a suitable fuse, the user must also account for characteristics such as aging effects, temperature
derating, overcurrent capacity and the definition of the rated current, which can vary by manufacturer and type. In
addition, the fuse that is selected must also be able to handle application-specific characteristics (e.g. overcurrent
that occurs in acceleration cycles).
The cross section of the power mains and the rated current of the overcurrent protection used are chosen according
to the current load so that the maximum current load for the cable cross section selected (based on the type of
wiring, see table) is greater than or equal to the current load in the power mains. The rated current of the overcurrent
protection must be less than or equal to the maximum current load for the cable cross section selected (based
on the type of wiring, see table):
I
Mains
≤
I
b
≤
I
Z
Mains
≤
Fuse
≤
Line/cable
Maximum current load for cable cross section I
Z
/ rated current for overcurrent protection I
b
[A] depending on
the type of wiring at an ambient air temperature of 40°C in accordance with IEC 60204-1
Wire cross section [mm²]
B1
B2
C
E
1.5
13.5 / 13
13.1 / 10
15.2 / 13
16.1 / 16
2.5
18.3 / 16
16.5 / 16
21 / 20
22 / 20
Table 715: Cable cross section of the mains supply line depending on the type of wiring
The tripping current of the fuse must not exceed the rated current for overcurrent protection I
b
.
Type of wiring
Description
B1
Wires in conduit or cable duct
B2
Cables in conduit or cable duct
C
Cables or wires on walls
E
Cables or wires on open cable tray
Table 716: Type of wiring used for the mains supply line
Summary of Contents for X20 System
Page 2: ......
