HIGH VOLTAGE FUSE-LINKS HIGH VOLTAGE FUSE-LINKS WITH THERMAL STRIKER HIGH VOLTAGE FUSES POWER NEEDS ONTROL
HIGH VOLTAGE FUSE-LINKS 1. General information High voltage fuse-links (hereinafter called HV fuse-links) are intended for protection of high voltage consumers (lines, transformers, motors, capacitors, switching devices etc.) against thermal and dynamic effects which are caused by the current which exceeds the permitted value as regards amplitude and duration. Owing to the low price, simple maintenance and small dimensions HV fuse-links are a good solution in cases when the usage of other sorts of protection would mean an excessive expenditure with regard to the price of the whole system. a. Short description of construction The construction of ETI HV fuse-link is shown on the figure 1. The base(1) of the fuse-links is made of qualitative brown glazed porcelain( 120 acc. to IE 672). A galvanically protected cap(2) of electrolitic copper is rolled by pressing into the groove of the tube. The tightness of this connection is assured by a special seal resistant to ageing and high temperatures. Inside the tube there is centrically installed an asteroid ceramic carrier(3) on which wire or strip melting elements(4) are coiled with precisely worked out weakened spots. As many as possible melting elements of pure silver are connected in a parallel way so that their thickness is as little as possible - and this is one of conditions for the correct function of the melting element in case of overload of the current. Melting elements are welded on both caps by means of a special copper strip. The inside of the tube is filled with quartz sand with exactly determined granulation. The sand guarantees good extinguishing of the electric arc in due time and in this way assures a high breaking capacity. An important element in the construction is also the striker system(5) the part of which is a striking needle - which in case that the melting elements fuses - springs out of the cap. This striking needle can function as an optical indicator in case that the melting element fuses or with its force it actuates some switching mechanism and in this way signals the state of fusing. Dimensions and characteristics of the force depending on the way of the striking needle are shown on the figure 2. ETI offers two versions of fuse-links: A version with the striker system - type (medium type acc. to IE 60282-1 item 4.14, table 11) and a version without striking system - type A. d ø 45 1 33 2 e 1 33 2 FIGURE 1 b. Advantages of HV fuse-links of the ETI production are: - high breaking capacity and reliable interruption of critical current - reliable interruption at minimal current - favourable characteristic of cut-off current - low power dissipation - switching voltages during interruption are essentially lower than prescribed - equal design for indoor and outdoor application - quality melting elements - reliable operation of the striker system. Force/Kraft F (N) 60 40 20 0 Travel/W Pot eg (mm) c. Quality control ETI has implemented a system of quality control according to ISO 9001 since 1993 which is certified by BVQI. 38 58 FIGURE 2
d. Accordance with standarts - IE 60282-1 (01/2002) urrent limiting fuses - IE 549 (1976) High-voltage fuses for the external protection of shunt power capacitors - IE 644 (1979) Specification for high-voltage fuse-links for motor circuit applications - IE 787 (1983) Application guide for the selection of fuse-links of high-voltage fuses for transformer circuit applications - EN 60282-1 (1983) High-voltage fuses, Part 1: urrent-limiting fuses - VDE 0670 Teil 4 (07/90) Bestimmungen für Wechselstromschaltgeräte für Spannung über 1kV (Sicherung) - VDE 0670 Teil 402 (05/88) Auswahl von strombegrenzenden Sicherungen für Transformatorstromkreise - DIN 43625 (11/83) Hochspannungs-Sicherung, Nennspannungen 3/3,6kV bis 30/36kV 2. Technical data onsidering the above mentioned standards there are two main types of HV fuse-links: A: back-up current limiting fuse-links B: general purpose fuse-links The graphical layout of the working regions of both types of fuse-links is shown in figure 3. back-up current limiting fuse links general purpose fuse links I N I TM I 1h I MIN I 1... rated current of HV fuse-link... minimum melting current of HV fuse-link... current which causes fusing of HV fuse-link in 1 hour... minimum breaking current... rated breaking capacity 0 Invv It I1h Im I1 not allowed region of function of HV fuse-link allowed region of function of HV fuse-link FIGURE 3 A. Back-up current limiting fuse-links Back-up current limiting fuse-links are intended for protection in a limited current region from the minimum current of fusing Imin to the rated breaking capacity I1. These fuse-links are not intended for protection of consumers in the current region between In and Imin. Their construction is of such sort that these currents can destroy the complete fuse-link. This type of HV fuse-links has been a standard product of ETI for a long time and therefore a lot of knowledge and experience have been built into it which assures a quality product and reliable protection. Their quality is attested also by positive type tests in ESI, Milan and IEL Warsaw test laboratories. Figure 4 shows an example of the oscilogramme of the test of breaking capacity of the fuse-link a- 24 kv/100a. We can see that the voltage of the arc is only 50.46 kv (=1.48x 2xUn ) which is essentially less than the upper limit which is permitted by the standard IE 60292-1 (2.2x 2xUn=74.7kV). Figure 5 shows I/t characteristics and figure 6 shows characteristics of cut-off current of back-up current limiting fuse-links. The internal mark of ETI for back-up current limiting fuse-links is a. With regard to the type of the indicator we distinguish between type a-a (without striker system) and type a- (with built-in striker system of medium power). U 20 kv EN 120 kj 2 I T 2 40 ka sec 20 70 120 170 220 270 320 370 420 5. msec ESI - gps :94/817638 FIGURE 4 1 2 4 5
Data for ordering and the most important electrical data of back-up current limiting fuse-links. rated voltage rated current type code No. dimens. dimens. rated breaking smallest breaking cold resistance power dissipation weight U N (kv) I N (A) e d capacity (ka) current I 3 = I min (A) R hl (mv) P v (W) (kg) 2 4223003 6 580 3,5 4 4223004 12 370 8,9 6 4223005 19 270 14,6 10 4223006 40 70 9,8 16 4223007 53 55 57,5 20,6 1,1 20 4223008 75 37,7 21,1 7,2 25 4223009 92 30,8 26,9 32 4223010 192 50 105 21,6 30,9 40 4223011 140 20,7 46,4 50 4223012 180 15,2 53,2 63 4223013 260 10,1 60 80 4223014 75 270 7,3 70,1 1,9 100 4223015 400 5,1 76,5 125 4223016 580 3,7 86,7 160 4223017 840 2,9 111 2 4233003 6 980 5,9 4 4233004 12 630 15,1 6 4233005 19 450 24,3 10 4233006 40 115 16,1 16 4233007 53 55 95,7 34,3 1,6 20 4233008 75 62,9 35,2 12 25 4233009 92 51,4 44,9 32 4233010 292 50 105 36 59,5 40 4233011 140 34 76,2 50 4233012 180 25,4 88,9 63 4233013 260 16,9 100 80 4233014 75 270 12,1 116 100 4233015 400 8,5 127 3,0 125 4233016 580 6,1 143 160 4233017 840 4,8 184
Data for ordering and the most important electrical data of back-up current limiting fuse-links. rated voltage rated current type code No. dimens. dimens. rated breaking smallest breaking cold resistance power dissipation weight U N (kv) I N (A) e d capacity (ka) current I 3 = I min (A) R hl (mv) P v (W) (kg) 2 4243003 6 1400 8,4 4 4243004 12 900 21,6 6 4243005 19 630 34 10 4243006 40 163 22,4 16 4243007 53 55 138 49,4 1,9 20 4243008 75 91,3 51,2 25 4243009 92 74,6 65,3 17,5 367 50 32 4243010 105 52,3 74,9 40 4243011 150 49,3 110 50 4243012 180 36,9 129 63 4243013 260 24,6 146 80 4243014 75 270 17,6 169 3,6 100 4243015 400 12,3 184 125 4243017 580 8,8 206 2 4253003 6 1960 11,8 4 4253004 12 1250 30 6 4253005 19 870 47 10 4253006 40 227 31,8 16 4253007 53 55 191 68,4 2,3 20 4253008 75 126 70,6 25 4253009 92 101 88,4 24 442 40 32 4253010 105 72 103 40 4253011 140 68 152 50 4253012 180 51 179 63 4253013 260 34 202 80 4253014 75 270 24,3 233 4,5 100 4253015 400 17 255 125 4253017 580 12,1 283 2 4263003 6 2900 17,4 4 4263004 12 1870 44,9 6 4263005 19 1300 70,2 10 4263006 40 341 47,7 16 4263007 53 55 287 103 2,8 36 20 4263008 537 25 75 189 106 25 4263009 92 152 133 32 4263010 105 108 154 40 4263011 140 102 228 50 4263012 180 76,5 268 75 5,1 63 4263013 260 51 304
B. General purpose fuse-links General purpose fuse-links are new in the production programme of ETI. They are intended for interruption of overload currents - from the ones which cause fusing of the fuse-link within one hour up to rated breaking capacities. This type of fuse-link is used above all in cases when the protected object has no additional protection against overload on the low voltage side and in this way there can appear such overloads on the secondary side which would destroy the ordinary back up fuse-link. The internal mark of ETI for general purpose fuse-links is g. As regards the construction they are completely the same as fuse-links which were described in the item 1.A. It also applies for them that they can be made in version without striker system (g-a) and in version with striker system (g-). The only difference between the two types of the fuse -links is in the melting element which is at the same time also the most important part of the back up current limiting fuse-link. It is made of silver strips (or wires) of high chemical purity and it is additionally weakened on several places. At the same time solder is applied on some spots (M-effect!). With wire melting elements the required function is achived by the correct shaping of Ag wire melting elements which are all treated according to a special procedure. Generally speaking: in the region of overloads between In and ca. 3In the active part of melting element is the one which has built in additional weakenings and solder while in the region of higher overloads the classical melting element operates. By careful design we determined exactly the points where the characteristics of both parts meet. The internal ETI mark for general purpose fuse-links is g. With regard to the type of the indicator we distinguish between the type g-a (without striker system) and the type g- (with built in striker system of medium power). Data for ordering and the most important electrical data of general porpose fuse-links. rated voltage rated current type code No. dimens. dimens. rated breaking smallest breaking cold resistance power dissipation weight U N (kv) I N (A) e d capacity (ka) current I 3 = I min (A) R hl (mv) P v (W) (kg) 6 4273006 13 210 9,1 10 4273006 53 18 121 14 1,6 16 4273007 28 91 31,2 20 4273008 37 38,3 19,9 12 25 4273009 292 50 52 28,7 23,3 32 4273010 69 26,3 37,7 75 40 4273011 85 22,4 50,2 3,0 50 4273012 120 19,1 70,2 63 4273013 165 15,3 91,1 6 4283005 13 420 18,1 10 4283006 53 18 242 28,1 2,3 16 4283007 28 182 62,4 20 4283008 37 76,6 39,8 24 25 4283009 442 40 52 57,5 46,7 32 4283010 69 52,6 75,4 75 40 4283011 85 45 100,8 4,5 50 4283012 120 38,3 140,7 63 4283013 165 30,7 182,7
HIGH VOLTAGE FUSE-LINKS WITH THERMAL STRIKER ETI, a well recognized manufacturer of low and high voltage fuse links has introduced an innovation to its range of products, the THERMO, a high voltage fuse link which also incorporates thermal protection. For rated currents 160A (rated voltage 12kV) and 100A (rated voltage 24kV) there is a choice of either the standard indicator with firing pin force of 50N and the new indicator with firing pin force of 80N. In addition, this new indicator is also temperature sensitive due to an additional integral element which reacts in cases of temperature increase of the fuse link due to various reasons. The reaction temperature is set at 100. This provides an important additional function to the VW fuse link, with a blow-out indicator which will react in the following circumstances: -In the event of an increase in ambient air temperature, a special integral mechanism will react by releasing the indicator pin (affecting the mechanism connected to the release device even in cases where the fuse link element has not cut out. - In the event of an incorrectly calibrated fuse link in relation to power supply user parameters (transformer..) and in cases where a fuse link is calibrated to react in surroundings close to the minimum breaking current. -In the event of an increase in temperature due to poor contact between the fuse link and its base. The standard function of the indicator mechanism in cases of a fuse link blow-out is completely independent and the thermal indicator does not affect the primary function of the fuse link. rated voltage rated current indicator type code dimension dimension rated breaking minimum breaking cold resistance power dissipation weight U N (kv) I N (A) (, medium) No. e d capacity (ka) current I 3 = I min (A) R hl (m ) P v (W) (kg) 6 4232005 25 280 15 10 A 4232006 40 81 10 16 4232007 75 49 16 20 A 4232008 63 90 40 20 25 4232009 100 29 21 32 A 4232010 150 18,5 25 2,6 292 69 40 4232011 200 14 29 50 A 4232012 225 12 40 63 4232013 40 330 8,3 43 80 A 4232014 360 7,4 72 100 4232015 400 6,7 101 12 40 A 4232111 200 14 31 50 4232112 225 12 40 63 63 A 4232113 330 7,7 42 80 4232114 292 88 360 6,9 62 4,0 100 A 4232115 400 6,7 85 125 4232116 40 450 6,3 170 160 A 4232117 500 5,5 280 50 4232212 225 12 40 63 63 A 4232213 330 8,3 42 442 69 80 4232214 360 7,3 62 40 100 A 4232215 400 6,7 85 3,8 125 4232216 500 5,7 130 442 88 40 160 A 4232217 875 4,3 177 6,8 rated voltage rated current indicator type code dimension dimension rated breaking minimum breaking cold resistance power dissipation weight U N (kv) I N (A) (, medium) No. e d capacity (ka) current I 3 = I min (A) R hl (m ) P v (W) (kg) 6 4252005 25 530 35 10 A 4252006 40 139 22 16 4252007 40 75 86,9 33 20 A 4252008 97 63,4 37 25 4252009 122 50,2 46 32 A 4252010 194 33,5 46 2,6 292 69 40 4252011 267 24,8 55 31,5 50 A 4252012 315 21,4 74 63 4252013 432 14,2 76 6 A 4252205 25 540 28 10 4252206 40 148 18 24 16 A 4252207 40 75 93,5 30 20 4252208 442 69 97 72,2 39 25 A 4252209 122 54 39 3,8 32 4252210 194 33,5 46 40 A 4252211 267 24,8 55 31,5 50 4252212 315 21,4 74 63 A 4252213 432 14,2 76 40 4252311 267 24,4 52 50 A 4252312 40 315 21,4 63 63 4252313 442 88 432 14,2 76 5,8 80 A 4252314 475 12,8 128 31,5 100 4252315 540 11,5 190
ETI Elektroelement d. d. Obrezija 5, 1411 Izlake, Slovenia tel. +386 (0)3 56 57 570 fax: +386 (0)3 56 74 077 e-mail: eti@eti.si www.eti.si