US 8,014,111 B2 · Method and device for preventing fire caused by defects in electric circuits and arrangements

Abstract

A method for preventing fire in electric circuits and arrangements includes measuring an electric current of a controllable section, separating a high frequency component therefrom, amplifying and rectifying a first harmonic signal, determining a spark current value, forming the first harmonic signal from a measured current signal range, measuring short-circuit and/or overload and/or a leak, and/or measuring the electric circuit voltage, in forming a warning and/or switching off signal of the controllable section. The signal amplitudes and/or other parameters including a spark striking-suppression cycle are measured for determining a spark current. The fire preventing device includes a unit for forming a signal of first and higher harmonics, a unit for determining a spark current quantity, a unit for measuring short-circuit and/or overload and/or leak currents, and/or electric circuit voltage measuring currents, units for forming a warning and/or switching off the controllable section signal. The spark current quantity determining unit has devices for measuring signal amplitudes and/or other parameters including a spark striking-suppression cycle.

Claims7

Dependent claims

A method of fire prevention from faults in electric networks or electric installations containing measurement of electric current of a controlled section, the method comprising:

forming a signal of a first harmonic and of a second and higher harmonic from a spectrum of a measured current;
measuring at least one of a short-circuit current measurement an overload current, a creeping current, or an electric network voltage, the short-circuit current and the overload current measured by allocation of a first harmonic signal out of the measured electric current of the controlled section, and at least one of the creeping current measurement or the electric network voltage measurement performed by at least one of a connection of a leakage current sensor, or feeding to the device the electric network voltage or electric installation voltage;
and
measuring, for sparking a current determination, a quantity of a pulse amplitude at at least one of a forming stage, a dying stage of a cycle of arc striking-extinction, or a pulse quantity of a forming stage of a cycle with an admissible amplitude.

1 more element

A method of fire prevention from faults in an electric network, comprising:

measuring an electric current in a monitored section of the electric network;
forming a signal of a first harmonic and of a second and higher harmonic from a spectrum of the measured current;
measuring at least one of a short-circuit current, an overload current, a leakage current, or an electric network voltage, wherein the short-circuit current and the overload current are measured by separating the signal of the first harmonic from the measured electric current of the monitored section;
measuring amplitudes of pulses for determining a magnitude of an arcing current in at least one of a forming or decaying stage of an arc striking-extinction cycle;
and
measuring a number of pulses having an amplitude exceeding a set value in the forming stage of the cycle.

3 more elements

Dependencies are inferred from the claim text.

Method and device for preventing fire caused by defects in electric circuits and arrangements

Life of this patent

Method and device for preventing fire caused by defects in electric circuits and arrangements

Life of this patent

Abstract

Claims7