Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
  • H01H85/02—Details
  • H01H85/04—Fuses, i.e. expendable parts of the protective device, e.g. cartridges
  • H01H85/05—Component parts thereof
  • H01H85/18—Casing fillings, e.g. powder
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
  • H01H9/30—Means for extinguishing or preventing arc between current-carrying parts
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31652—Of asbestos
  • Y10T428/31663—As siloxane, silicone or silane

Definitions

• the Extinguishing medium according to the invention consists of a pasty to solid silicone matrix, which with selected mineral Filler is filled and has a much improved Extinguishing characteristics.
• the extinguishing medium according to the invention confers in the applications mentioned, for example HV fuses, which contain an extinguishing medium according to the invention, a significantly improved switching characteristics.
• Extinguishing media for extinguishing arcs in electrical devices for example in fuses, are known per se.
• the function of the extinguishing media in electrical fuses is that the extinguishing medium withdraws enough energy from the arc or Arc cools so much that it is at zero current goes out.
• Sand is generally used as the extinguishing medium.
• the Switching characteristics of a sand contain fuse, therefore essentially by the composition of the sand and by its average grain size distribution and grain shape influenced. That is why from different manufacturers strongly differing extinguishing sands are used.
• I n rated current, also referred to as Irated
• large fault currents are relatively easy to handle by introducing weak points in the current path in a manner known per se. If a sufficiently high voltage is generated via the base voltage, these weak points lead to the extinguishing of the arcs in the zero current crossing.
• a tin particle (M-Spot, Metcalf effect) is applied to the fuse wire in the middle of the fuse.
• the tin diffuses into the silver.
• the resulting intermetallic phase AgSn 2 has a significantly lower melting point than the base material (silver) and melts at the point where sufficient tin has diffused into the silver wire.
• An arc forms at this point. This arc is now extinguished by the extinguishing medium, usually quartz sand, as a result of the energy withdrawal that occurs when the sand is melted.
• the fault current In order to provide sufficient energy to melt the sand, the fault current must generally be at least three times higher than the nominal current of the fuse. With smaller currents, the arc cannot grow accordingly because the energy is not sufficient to melt the base points on the fuse element (wire) and the arc cannot extinguish because the energy is insufficient to melt the fuse sand to the necessary extent. The arc therefore continues to burn stably over a defined distance within the fuse. The locally limited thermal energy introduced leads to an excessive thermal gradient within the fuse in the area in which the arc burns, which can lead to the fuse exploding. In order to be able to interrupt currents that lie between the nominal current and the minimum breaking current of around 3I N , it is necessary to improve the cooling of so-called low-current arcs.
• silicone polymers preferably in pasty to solid form, which contain known mineral compounds in suitable form and concentration as fillers, are excellent extinguishing media for extinguishing arcs in electrical fuses.
• the extinguishing media according to the invention it is possible to interrupt or extinguish arcs which are generated by currents which are below the minimum switch-off current of approximately 3I N and currents which are significantly smaller than the nominal current without the disadvantages described above occurring .
• arcs can be extinguished at 0.67 times the nominal current I N.
• Very fine can also be used with the extinguishing medium according to the invention Particles of cooling active media in large quantities directly and permanently be positioned near the expected arc. Due to the large surface area of the fine particles, the Cooling performance significantly improved, with the oxidation of the Silicones hardly conductive through the arc and none strongly toxic decomposition products arise. With the use of the Extinguishing media for arc quenching can Dimensions of fuses, such as HV fuses, at same performance can be significantly reduced. In addition, the Distance between parallel fuse wires from currently at least about 16 mm when using the inventive Extinguishing medium can be reduced down to about 1 mm without there is a short circuit between spiral turns of the Safety wire comes during or after the switching process.
• the present invention relates to an extinguishing medium in pasty to solid form for extinguishing arcs, consisting of a silicone polymer or a mixture of such silicone polymers, are characterized in that this silicone polymer or Mixture of silicone polymers as filler at least one mineral compound or a mixture of such compounds in powdery form, preferably with an average Grain size in the range from 500 nm to 500 ⁇ m, and in one Concentration of at least 10 percent by weight based on the Total weight of the extinguishing medium.
• the present invention further relates to the use of the Extinguishing medium according to the invention for extinguishing arcs in Overcurrent protection elements, preferably in fuses, for example in fuses in the household, in High-voltage high-performance fuses (HV fuses) in Distribution network or substrate fuses, in electronics, the Microelectronics or in high voltage technology or in repetitive fuses, preferably in PTC elements.
• Overcurrent protection elements preferably in fuses, for example in fuses in the household, in High-voltage high-performance fuses (HV fuses) in Distribution network or substrate fuses, in electronics, the Microelectronics or in high voltage technology or in repetitive fuses, preferably in PTC elements.
• the present invention further relates to overcurrent protection elements, preferably fuses, substrate fuses in the Electronics, in microelectronics or in high voltage technology, repetitive fuses, preferably PTC elements, which contain an extinguishing medium according to the invention.
• overcurrent protection elements preferably fuses, substrate fuses in the Electronics, in microelectronics or in high voltage technology, repetitive fuses, preferably PTC elements, which contain an extinguishing medium according to the invention.
• the present invention also relates to a method of manufacture the electrical devices according to the invention, in particular Fuses as described below.
• Suitable starting products for the production of the inventive Extinguishing media are flowable, preferably curable, cyclic, linear or branched organopolysiloxanes or a Mixture of such compounds. These are preferably liquid to pasty, so that the filler is relatively high Allows concentration to be incorporated.
• the one from the starting polymer produced mass containing the filler as a rule a significantly higher viscosity than the starting polymer itself and can be used uncured if necessary.
• curable polysiloxane or a curable polysiloxane mixture used at room temperature or at elevated temperature preferably by polyaddition but also by polycondensation hardens.
• R 2 preferably has one of the meanings of R, where R preferably denotes methyl or phenyl, and both methyl and phenyl can be present in the molecule.
• the ratio of methyl to phenyl is given by the flowability or processability and fillability of the compound or the compound mixture.
• R is preferably methyl.
• the compound of the formula (I) is generally a mixture of homologous compounds of the formula (I), which is known to the person skilled in the art.
• the compound of the formula (I) is a cyclic organohydrogenpolysiloxane or organovinylpolysiloxane, this is composed of - [Si (R) (R) O] units and / or - [Si (R 1 ) (R 2 ) O] units, For example, only composed of - [SiH (R 2 ) O] units, which form a ring with preferably 4 to 12 such units.
• the ring-shaped siloxanes however, the ring-shaped oligomeric polydimethylsiloxanes having 4 to 8 siloxy units are preferred.
• a curable silicone resin molding composition is used as a curable mixture consisting of two components.
• R 2 means hydrogen at least for some of the molecules present in the one component.
• a complex compound or a mixture of such complex compounds from the group of the rhodium, nickel, palladium and / or platinum metals, such as Catalytically active compounds for addition reactions between SiH bonds and alkenyl radicals are described in detail in the literature and are known to the person skilled in the art.
• Pt (0) complexes with alkenylsiloxanes as ligands or Rh catalysts are preferred in catalytic amounts of preferably 1 to 100 ppm of platinum, calculated on the amount of the compounds containing the reactive groups.
• the two terminal silyloxy groups of the compound containing the radical -A-CH CH 2 , independently of one another, preferably mean dimethylvinylsiloxy, n then preferably denoting zero.
• the individual starting components preferably have a viscosity in the range from about 10 cSt to 10,000 cSt, preferably in the range from 100 cSt to 10,000 cSt and preferably in the range from 500 cSt to 3,000 cSt, measured according to DIN 53 019 at 20 ° C.
• the two components, the catalyst and the filler are mixed in any order, whereupon the resulting free-flowing mixture is used, for example by bringing it into the desired shape, or by applying it to the safety wire or entering it in the fuse , and the mixture cures.
• the hydrogen silane compound and the vinyl silane compound are used to produce the curable silicone resin molding composition at least in equimolar amounts.
• Systems can also be used in the same way where the catalyst has already been introduced into the resin and / or hardener component prior to mixing.
• condensation-crosslinking silicone resin systems can also be used be used.
• Condensation curing silicone resin systems are known per se. They network in particular on the ground the existing [ ⁇ Si-OH] groups, which are in the crosslinking process Form [ ⁇ Si-O-Si ⁇ ] bonds.
• condensation crosslinking systems Disadvantage that when crosslinking or hardening, fission products form, especially water, causing corrosion or failure the fuse according to the invention can lead.
• Geopolymers such as trolites and / or zeolites based on aluminum silicates or other alkaline earths, glasses, mica, such as micro mica and / or ceramic particles.
• Alumina containing hydrated water can be used as filler.
• Compounds which contain magnesium ions (Mg +2 ) are preferred. Particularly preferred are compounds (natural and synthetic sands etc.) which contain silicon, aluminum and / or magnesium ions, such as MgCO 3 , Mg (OH) 2 .4MgCO 3 .4H 2 O; Mg (OH) 2 ; MgO; MgCl 2 .5Mg (OH) 2 .7H 2 O.
• a filler is also preferred as two or multiphase mixture consisting of silicon dioxide, aluminum oxide, Aluminum trihydrate, magnesium hydroxide and / or titanium dioxide, where the extinguishing medium about 40-80% by weight, based on the Total weight of the extinguishing medium.
• Preferred as filler Boric acid is also used, which is used during processing a few minutes (preferably at most 15 minutes) at 80 ° C was dried.
• the average grain size or particle size of the filling material is preferably in the range of 500 nm to 500 ⁇ m, preferably in the range from 10 ⁇ m to 250 ⁇ m.
• Grain sizes are preferably in diameters Range from 20 ⁇ m to 150 ⁇ m, preferably in the range from 30 ⁇ m to 130 ⁇ m.
• coarser average grain sizes they are Diameter preferably in the range from 500 nm to 50 ⁇ m, preferably in the range from 0.5 ⁇ m to 10 ⁇ m.
• the average Grain size distribution or particle size distribution is not critical and is preferably in common areas such as these are known for fillers when they are processed into polymers.
• the proportion of the filler in the silicone resin is preferably in the Range from 5% by weight to 95% by weight, preferably in the range from 40 % By weight to 85% by weight, and in particular in the range from 60% to 80% by weight, calculated on the total weight of filler and polymer.
• Fill levels at the physical are preferred realizable upper limit at which the fluidity or the processing of the uncured mixture is straight what is usually given with a degree of filling of about 80 % By weight is given.
• the extinguishing medium according to the invention is so made this this very little and practically none Includes air pockets.
• the arc is cooled significantly more if the extinguishing medium has a finer average grain size, since with smaller particles to be melted a larger particle surface for the Withdrawal of energy from the arc is available and the particles are melted faster.
• a comparatively fine-grained sand usually consists of rounded particles, which - in comparison with coarse sand - results in a different trip characteristic and in particular poorer extinguishing behavior.
• it is not only the available particle surface or the average grain size that is important, but also the grain shape.
• Coarse sand for example, has a quick response and a good extinguishing capacity for small overcurrents in the range from 3I N ⁇ I K ⁇ 8I N (where I K means a variable in the range from 3I N to 8I N ), but has a poor extinguishing capacity for high currents in the range of I K > 8I N.
• Fine sand has a slow response and has the advantage of good quenching power for high currents in the range of I K > 8I N , but has poor quenching power for low overcurrents in the range of 3I N ⁇ I K ⁇ 8I N.
• fine sand also has the problem of separating and solidifying the fine particles, which over the course of the operating life of a fuse of around 25 years can lead to the formation of a larger air-filled cavity in the fuse, which due to the poor thermal conductivity of the air There is a risk of an explosion when switching.
• the excellent extinguishing capacity of the extinguishing medium according to the invention which is preferably evenly filled with a fine-grained filler, can be explained by the fact that the arc is cooled by the large surface area of the filler on the one hand, and the easily oxidizable silicone resin on the other hand. This synergistic effect of the combination according to the invention was not to be expected.
• the present invention also relates to a method of manufacture the electrical devices according to the invention, in particular fuses, which is characterized in that a liquid to pasty silicone compound or a mixture such silicone compounds with a suitable filler or a mixture of such fillers in the desired concentration evenly mixed in any order, the obtained Mixes into a desired shape and / or on the Applies safety wire of the device and / or inside of the device and then the mixture, if necessary beforehand and / or after introduction into the Interior of the fuse, hardens or allows to harden.
• the liquid to pasty Filled silicone mass according to the invention into solid molded parts process or harden, e.g. Tubes, elliptical tubes or rod-shaped elements with a trapezoidal cross-section, which on the securing element with or without a carrier on the Carrier of the securing element can be pushed on.
• the silicone compound filled according to the invention can also directly applied to the fuse wire or to the fuse element and then hardened, the silicone mass for example by diving, brushing, trickling or watering can be applied.
• a vulcanization individual parts are also conceivable, e.g. a vulcanization of separate sections of the securing element, the carrier of the Securing element, the securing body (on the inside) or the security element itself.
• the extinguishing medium according to the invention is used according to the invention for the Extinguishing any arcs in electrical devices, Devices and systems used, preferably in overcurrent protection elements, like fuses in general, for example Fuses in households, high-voltage high-performance fuses (HV fuses) in the distribution network or substrate fuses.
• overcurrent protection elements like fuses in general, for example Fuses in households, high-voltage high-performance fuses (HV fuses) in the distribution network or substrate fuses.
• HV fuses high-voltage high-performance fuses
• Such fuses are the ABB (CEF) 12 kV-6A (backup) fuse or ABB (CEF) 24 kV-63A fuse; the EFEN 6 / 12kV-6.3A (all purpose) fuse; the FERRAZ 12kV-6.3A- (all purpose) security; the SIBA 6 / 12kV-16A (all purpose) fuse; each with ceramic extinguishing medium; the Bussmann High Voltage-12kV-80A (full range) H.R.C. Fuse whose Fuse elements sit on a glass support with one Glazing of the surface and ceramic extinguishing medium. Information about the dimensions, components and functional parameters, or electrical properties, such fuses are the respective catalogs published by the manufacturers remove.
• HV fuse links with temperature limiter code HH1-03 / 97, from SIBAbutbau GmbH, Borker Strasse 22, D-44534 Lünen, Germany, or the catalog Bussmann, High Voltage Products, identifier HVP-98, Bussmann Division, Cooper (UK) Ltd, Burton-on-the-Wolds, Leicestershire, LE12 5TH UK (additional information at http://www.bussmann.com), or the catalog HV fuses, HV fuse carriers, Issue 03/98, EFEN Elektrotechnische Fabrik GmbH, P.O.Box 1254, D-65332 Eltville, Germany. See also CD-ROM, Interactive Catalog Ferraz 1999.
• the extinguishing medium according to the invention not only in fuses, but in the entire area of low voltage technology, the Electronics and microelectronics up to high voltage technology for Arc extinguishing applicable. Also arise in electronics Arcs that must be extinguished.
• overcurrent protection elements extinguishing media on the substrates, that is in particular ceramic or glass, on which the securing elements are upset, tied up.
• the surfaces cleaned (ultrasound, degreasing e.g. with isopropanol or Ethanol) and with a primer, for example DOW CORNING 1200 OS Primer, brushed, dipped or sprayed.
• a primer for example DOW CORNING 1200 OS Primer
• Example 2 is repeated with the proviso that the quartz powder is replaced by aluminum oxide Al 2 O 3 .0-30 .mu.m from Hermann C. Starck Berlin GmbH & Co. KG, the aluminum oxide drying at 600 ° C. for 120 minutes before use becomes. The degree of filling is 60% by weight. A minimum breaking current (I min ) of 0.67 I N was measured for a 24kV / 40 A CEF fuse made with this extinguishing medium.
• I min A minimum breaking current
• Example 2 is repeated with the proviso that the quartz powder is replaced by boric acid for industrial use, powdered, from Siegfried CMS AG, the boric acid being dried at 80 ° C. for 15 minutes before use and then in a ball mill with agate balls of one Diameter of 10 mm was crushed. The degree of filling is 60% by weight. A minimum breaking current (I min ) of 0.67 I N was measured for a 24kV / 40 A CEF fuse made with this extinguishing medium.
• I min A minimum breaking current
• I min minimum cut-off current
• Example 2 is repeated with the proviso that the quartz powder is replaced by aluminum oxide E 600, 0-1 ⁇ m from Saint Gobain Industrial Ceramics (USA), the aluminum oxide being dried at 600 ° C. for 120 minutes before use. The degree of filling is 40% by weight. A minimum cut-off current (I min ) of 0.67 I N was measured for a 24kV / 40 A CEF fuse made with this extinguishing medium.
• I min minimum cut-off current

Landscapes

• Compositions Of Macromolecular Compounds (AREA)
• Fuses (AREA)

Priority Applications (5)

Applications Claiming Priority (1)

Publications (1)

Family

ID=8174743

Family Applications (1)

Country Status (5)

Cited By (5)

Families Citing this family (8)

Citations (5)

Family Cites Families (13)

• 2000
  • 2000-06-07 EP EP20000810495 patent/EP1162640A1/fr not_active Withdrawn
• 2001
  • 2001-05-31 US US09/867,654 patent/US6645637B2/en not_active Expired - Fee Related
  • 2001-06-05 PL PL347881A patent/PL196151B1/pl unknown
  • 2001-06-05 AU AU50127/01A patent/AU774864B2/en not_active Ceased
  • 2001-06-06 NO NO20012784A patent/NO20012784L/no not_active Application Discontinuation

Patent Citations (5)

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events