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Dimensions
Section 12
11
400 Hz network (cont.)
Technical advice
Compatibility of residual current devices at 400 Hz:
Depending on the type and the technology employed, a residual current device
designed for a frequency of 50/60 Hz will or will not be capable of ensuring
protection for users in accordance with the requirements of the standard.
Type of protection and
type of equipment
Use possible on network of
400 Hz frequency
Limit
A type
Not compatible
Trip threshold exceeding the
limit given by the curve
AC type
Not recommended
Excessive sensitivity with risk
of unwanted tripping (poor
guarantee of continuity of
service)
Si
type iID
YES
Vigi iC60
Not compatible
Trip threshold exceeding the
limit given by the curve
iDPN Vigi,
YES
Note: The choice of an iID residual current circuit breaker ensures protection for users at 400 Hz
while ensuring good continuity of service.
At 400 Hz, the test function of residual current devices designed for 50/60 Hz is
not operational due to the increase in the trip threshold.
Auxiliary function
Voltmetric releases
If a circuit breaker needs to be provided with a voltmetric release whose control
circuit is powered by the 400 Hz network, it is necessary to use a release auxiliary of
appropriate characteristics for 400 Hz networks:
Type
Voltage
Cat. no.
Undervoltage release iMN 115 V AC - 400 Hz
A9A26959
15
F f
50/60 100
300
ƒ
(Hz)
1000
10
5
6
1
400
Frequency factor
Frequency
Variations in the ventricular fibrillation threshold for shock durations exceeding the period of
cardiac cycle (as per IEC 60479-2).
Earth leakage protection devices
The residual current device trip thresholds designed for 50/60 Hz increase with the
frequency, but since the human body is less sensitive to the passage of a current at
400 Hz, protection is still ensured for the users.
According to the IEC 60479-2 standard, at 400 Hz the ventricular fibrillation
threshold is higher by a ratio of 6 (which means that the physiological effect of a
180 mA current at 400 Hz will be the same as that of a 30 mA current at 50/60 Hz).