Fuse Techno and Operation

Transcription

1 Fuse Techno and Operation

2 Technology Styles Ferrule Euro/ N.Am Tag British/ German Blade Euro/ N.Am Flat Euro/ N.Am 2/ 12

3 General exploded of the PSC-LR Technology Fuse-elements Body Sand (inside the body) Terminals 3/ 12

4 gg standard fuse with M effect fuse-element M effect 0% lead 0% cadmium Body It complies with the 2 nd design of European electronic scraps guideline 100% safe with voltage free metal grip lugs 4/ 12

5 Dual-element Example of design used for Time Delay fuses Fuse element for short circuit Fuse element for overloads Plunger I 5/ 12

6 Fuses under over current conditions Overloads 1000% I FLA Fast-acting :gg, gn, gd,j, L.. are designed to interrupt low overloads. Time-delay : AJT, A4BQ, A6D, ATDR are designed to interrupt low overloads. Semiconductors Fuses type gr and gs are designed to interrupt low overloads. Semiconductors Fuses type UR and SR can not interrupt overloads Motor circuit fuses type am can not interrupt overloads. Short-circuits > 1000% I FLA All fuse types will create several arcs in series by simultaneously melting several rows of notches to achieve the arc control. Silica sand: absolutely necessary to get the shortest arcing time, better current limitation, less I²t and energy. I FLA = Full Load Amps 6/ 12

7 Overloads operation of fuses with M effect Tin or tin-alloy solder added on element. On sustained overload, heat produced by the element melts the tin-alloy solder. Tin goes through the element and creates a gap. An arc starts. Safe oveload operation! 7/ 12

8 Overload operation with a dual-element fuse Thermal mass provides time-delay Low operating temp (< 200 C)... Solder melts Plunger of overload section retracts... Arc created Arc extinguished by distance and pressure Specialized overload operation...no performance compromises! 8/ 12

9 Short circuit interruption Fusibles without M effect am, URD, A50QS, A70QS etc.. Fuses with M effect fuse elements gg, grb, class J, L fast acting etc.. All notches melt simultaneously for high-magnitude currents. Multiple arcs in series (4 in this example) are created. Melted sand = fulgurite (glass-like substance) Result is energy limitation and safe breaking operation! 9/ 12

10 Short circuit interruption with a dual-element fuse The process and the result are the same as for the fast acting fuses and semiconductor fuses. All notches melt simultaneously for high-magnitude currents. Multiple arcs in series (4 in this example) are created. Melted sand = fulgurite 10 / 12

11 Dual-element another example of design used for Time Delay fuses A Ferrule (rejection ferrule) B Overload element (spring loaded) C Eutectic solder D Filler (quartz sand) E Fuse body F Non rejection ferrule G Short circuit element 11 / 12

12 Comparison of the curves of 5 fuses rated 100 A Fuse element with M effect IEC Class gg Mersen gg 100 A Full Range curve Dual element fuse UL Class J Time Delay Mersen AJT 100 A Full Range curve Fuse element with M effect UL Class J Fast acting Mersen A4J 100 A Full Range curve Back up protection fuse element IEC Class am Mersen am 100 A No operation above 60 S Semiconductor fuse IEC Class ar Mersen PSC URD 100 A No operation above 30 S 12 / 12