Siemens 3VA1 100 A, Руководство пользователя

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Description
2.8 Electronic trip unit
3VA molded case circuit breakers
Manual, 04/2015, A5E03603177010-02
101
2.8.5 Measuring with a Rogowski coil
The Rogowski coil is a toroidal coil without a ferromagnetic core. It is used as a component
in electronic measuring devices to measure alternating current.
Advantages of the current sensor:
● Each transformer can be optimized for its task and operating points
–
Transformers for power generation
– Transformers for measurement
● Higher accuracy of current measurement and therefore higher accuracy for ground-fault
currents
A power measurement is made possible by the more exact and more linear measurement of
the current together with the integrated voltage tap in the molded case circuit breaker.
Accuracy levels of the specified measured values of the 8-series ETU, including the
integrated current sensors
Interpretation of measured values
PF Power factor
Measured current and voltage values are always positive.
The "normal" direction of energy flow of the 3VA molded case circuit breaker is top down
(can also be adjusted using the powerconfig software), corresponding to operation in
quadrants Q1 and Q4. If the molded case circuit breaker is supplied from below, it is
operated in quadrants Q2 and Q3.