DE2062694A1 - Residual current circuit breaker - Google Patents

Description

Residual current circuit breaker Addendum to patent ............... (patent application P 2 044 302.1 -our VPA 70/4032) The main patent relates to a residual current circuit breaker with a summation current transformer, which has a magnetic core, with primary windings for connection to a circuit to be monitored and with a secondary winding, which act on the excitation winding of a switch mechanism for a switching device Trigger magnet feeds, the magnetic core has an induction stroke that is so large is that one by a pulsating, in a primary winding of the summation current transformer flowing direct current residual current in the secondary winding induced voltage to the Actuation of the release magnet is sufficient.

To achieve such an induction stroke, the magnetic core E.g. a specially pretreated toroidal tape core made of an iron-nickel alloy certain composition. This particular pretreatment and composition of the material from which the magnetic core is made, however, is sufficient to achieve a Induction thrust not required if this magnetic core according to the invention Cutting tape core is. Due to the two air gaps, the cut ribbon core has opposite a sheared hysteresis loop and thus a considerably larger induction stroke, which is the difference between the saturation induction and the remanent induction is defined.

Cut tape cores as such are known, but they were used to Simplification of the assembly of fully wound coils, e.g. developed for chokes. Since the primary windings of a summation single converter in a PeWier current circuit breaker but only from one of the ring-shaped magnetic core of the summation current transformer enclosed wire or, like the secondary winding, only very few turns have fault current circuit breakers with a cut ribbon core for the summation current transformer has not become known, but the development of residual current circuit breakers went in favor of toroidal tape cores, as these because of their greater permeability may have smaller geometric dimensions.

The invention and its advantages are explained in more detail with reference to the drawing: The drawing shows a schematic representation of a fault current circuit breaker 3 according to the invention, which is used to monitor the lines R / U and Mp of an electrical Plant serves. It has a summation current transformer 4 with a magnetic core 5. Of the Magnetic core 5 is a cut tape core, which consists of two halves, which are through a Tension band 5a are held together, and which has two air gaps 5b. The tape thickness can be, for example, 0.006 to 0.3 mm. This magnetic core encloses the two Wires 6, which represent primary windings and which are in the lines to be monitored R / U and Mp lie. Furthermore, a secondary winding 7 is seated on the magnetic core 5, which is connected to the excitation winding 9 of a trip magnet is connected. This trigger magnet 8, which can be a holding magnet or a work magnet, works via a mechanical one Connecting part 8a on the switch lock 10, which via a switch rod 10a the switching contacts 11 located in the lines to be monitored R / U and Mp are actuated.

The residual current circuit breaker according to the drawing trips when the An alternating current fault current flows through wires 6, because of the air gap 5b is the induction stroke of the cutting tape core 5, i.e. the difference between its Saturation induction and its remanence induction, however, sufficiently large that also caused by a pulsating DC fault current flowing in the wires 6 evoked change in magnetic flux to induce the response voltage of the tripping magnet 8 excess voltage in the secondary winding 7 of the summation current transformer 4 is sufficient and the fault current protection switch also when such a flow pulsating DC fault routine triggers.

*) of the cutting tape core It is favorable when the Induction stroke of the cutting tape core 5 is more than 3000 Gauss, in particular at least 4000 Gauss.

Perner it is advantageous if the relative permeability of the cutting tape core 5 is as large as possible, e.g. at least 1000, since in this case only one is proportionate low magnetic excitation required to trip the residual current circuit breaker and therefore the summation current transformer of the residual current circuit breaker is only small needs to have geometric dimensions.

1 patent claim 1 figure

Claims (1)

Patent claim Fchler's extreme protection switch with a summation current transformer, which has a magnetic core with primary windings for connection to one to be monitored Circuit and with a set secondary winding that connects the excitation winding to a Switching mechanism for a switching device feeds actuating release magnets, whereby the magnetic core has an induction stroke that is so large that a pulsating DC residual current flowing in a primary winding of the summation current transformer The voltage induced in the secondary winding is sufficient to actuate the release magnet, according to patent ........... (patent application P 2 044 302. 1 - our VPA 70/4032), thereby characterized in that the magnetic core is a cut tape core.