Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
149 words
A power switching apparatus comprising: at least one electrical conductor to which high voltage can be applied; a series circuit arranged in a cable run of the electrical conductor and formed by a switching point and a current-limiting element; an operating apparatus which interacts with the current limiting element in order to operate the switching point, wherein the current-limiting element has n-series connected parallel circuits each having at least one PTC thermistor and at least one varistor connected in parallel with each PTC thermistor, n being a natural number greater than 1; and connections of one of the n-series connected parallel circuits at two junction points being operatively connected to the input of the operating apparatus, wherein the PTC thermistor of said one n-series connected parallel circuit which acts on the input of the operating apparatus has a greater resistance than remaining PTC thermistors of the current limiting element.
Claim 2
Dependent Claim
149 words
A power switching apparatus comprising: at least one electrical conductor to which high voltage can be applied; a series circuit arranged in a cable run of the electrical conductor and formed by a switching point and a current-limiting element; an operating apparatus which interacts with the current limiting element in order to operate the switching point, wherein the current-limiting element has n-series connected parallel circuits each having at least one PTC thermistor and at least one varistor connected in parallel with each PTC thermistor, n being a natural number greater than 1; and connections of one of the n-series connected parallel circuits at two junction points being operatively connected to the input of the operating apparatus, wherein the PTC thermistor of said one n-series connected parallel circuit which acts on the input of the operating apparatus has a greater resistance than remaining PTC thermistors of the current limiting element.
Claim 3
Dependent Claim
24 words
The power switching apparatus as claimed in claim 1, wherein the switching point is part of a switching device designed as a load-break switch.
Claim 4
Dependent Claim
16 words
The power switching apparatus as claimed in claim 2, wherein the load-break switch is a switch-disconnector.
Claim 5
Dependent Claim
26 words
The power switching apparatus as claimed in claim 1, wherein a relay is arranged between the two junction points and the input of the operating apparatus.
Claim 6
Dependent Claim
23 words
The power switching apparatus as claimed in claim 1, wherein the two junction points are connected to the input of the operating apparatus.
Claim 7
Dependent Claim
37 words
The power switching apparatus as claimed in claim 4, wherein the relay of the operating apparatus has a threshold detector which is controlled by voltage present at the two junction points when a PTC transition takes place.
Claim 8
Dependent Claim
40 words
The power switching apparatus as claimed in claim 1, wherein an uninterrupted operating voltage of the varistors is in each case at least 100 V, and an overvoltage in a switching state is in each case at least 300 V.
Claim 9
Dependent Claim
40 words
The power switching apparatus as claimed in claim 7, wherein an uninterrupted operating voltage of the varistors is in each case at least 140 V, and an overvoltage in a switching state is in each case at least 340 V.
Claim 10
Dependent Claim
27 words
The power switching apparatus as claimed in claim 1, wherein a distance between electrical connections of the PTC thermistors is in each case at least 3 mm.
Claim 11
Dependent Claim
29 words
The power switching apparatus as claimed in claim 9, wherein a distance between electrical connections of the PTC thermistors is in each case at least 4 to 6 mm.
Claim 12
Dependent Claim
35 words
The power switching apparatus as claimed in claim 1, wherein the PTC thermistor which has the greater resistance is cooled to a reduced extent or has a smaller cross section than the remaining PTC thermistors.