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11/50
Dimensions
Section 12
11
400 Hz network
Technical advice
Compatibility of 50/60 Hz equipment with a 400 Hz
network
The performance of products designed for domestic frequencies of 50/60 Hz is
impacted by the specific properties of networks of 400 Hz frequency.
Phenomena due to the increased frequency influence the behaviour of the copper
components of transformers, cables and protective equipment.
Some types of equipment designed for 50/60 Hz networks may not be suitable.
You should check whether or not a product is compatible and also apply any
correction factors given by the manufacturer.
Circuit breakers
Depending on the technologies used, modular circuit breakers designed for
50/60 Hz can be used at 400 Hz.
To choose the performance of a modular circuit breaker:
b
b
do not take any thermal derating into account
(In at 400 Hz is equivalent to In at 50 Hz).
b
b
increase the magnetic tripping threshold, according to the table below.
b
b
check that the short-circuit current on the installation is less than the breaking
capacity of the circuit breaker. The breaking capacity of the circuit breakers at a
frequency of 400 Hz is the same as at frequencies of 50/60 Hz. This characteristic
is generally complied with, due to the fact that the short-circuit current of a 400
Hz generator is relatively low. In most cases, the generator Isc does not exceed
four times the rated current.
Circuit breaker
Curve
Magnetic trip thresholds
50 Hz
400 Hz
Tolerance
iDPN
B
4 In
6 In
± 20 %
C
8 In
12 In
D
12 In
18 In
iC60
B
4 In
5.6 In
C
8 In
11.2 In
D
12 In
16.8 In
C60
B
4 In
5.1 In
C
8.5 In
10.9 In
D
12 In
15.4 In
C120
The NG125 and C120 circuit breakers are not suitable for networks of
400 Hz frequency. Refer to the Compact NSX offer.
NG125