Low Voltage Fuses. Safety in Focus. ZVEI.ppt / / 1

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1 Low Voltage Fuses Safety in Focus ZVE.ppt / / 1

2 Applications, Product Advantages Fuses protect Human life Electrical circuits Electrical products Electronics Cables and conductors Product advantages Very high breaking capacity in very small dimensions Effective current limitation very low peak currents Fine tuned discrimination Low power dissipation Very high reliability and resistance to aging Simple use ZVE.ppt / /

3 Structure of an NH- Fuse NH- Fuse-base NH- Fuse-link NH Fuse-handle Knifeblade contact indicator Endplate with gripping-lug Fusible element Ceramic body M-effect material Quartz sand ndicator wire Endplate with gripping-lug Knifeblade contact ZVE.ppt / / 3

4 Structures of D- Fuse and D0- Fuse D- Fuse D0- Fuse D-Fuse-base Touch protection cover Screw cap/fuse carrier D0-Fuse-base Touch protection cover Screw cap/fuse carrier Fusible element Fusible element Gauge Piece (Screw Gauge) D-Fuse-link Gauge Piece (Ring Adapter) D0-Fuse-link ZVE.ppt / / 4

5 Standardized Characteristics EC/EN 6069 min t s Halbleiter Semiconductor ar, gr ar,gr Kabel- Cable und and Leitungsschutz conductor gg gg (gl) 1. Letter a = partial range g = full range s ms Schaltgeräteschutz Motor protection am am. Letter G (L) = Cable and conductor protection M = Motor(switchgear) protection R = Semiconductor protection x / N ZVE.ppt / / 5

6 Function of Fusible elements at Overloads and Short-circuits t Overload: min s Limit of Diffusibility Overload Melting c Temperature M-effect ca. 170 C Prearcing time current-characteristic Constrictions Short Circuit tmelting Temperature Copper 1083 C, The M-effect material diffuses into the copper fusible element. The melting temperature is lowered to approx. 170 C Short circuit: Due to the high heat of the current the copper fusible element melts on all constrictions ms N (4...8) N Melting temperature approx C ZVE.ppt / / 6

7 Function of the M-Effect Material Fusible element without M-effect Fusible element with M-effect New Copper New M-effect Material J p Cu J p nterruption at approx C Overload J p J p alloy M-effect / Cu nterruption at approx C J p ZVE.ppt / / 7

8 State of Fusible Elements before and after the nterruption of the NH- fuse-link NH-fuse link size 00 / 63 A / AC 500V characteristic gg acc. EC 6069 Rated current n = 63 A Overload 5 = 16 A Short-circuit = 5 ka Short-circuit 1 = 10 ka ZVE.ppt / / 8

9 Cut-off Oscillogram of a Fuse Arcing current Max. Peak Current Prospective Short-circuit Current t U Arc Voltage System Voltage t S Pre-arcing time t S t LB t t LB Arcing time t A t A Operating time ZVE.ppt / / 9

10 Discrimination by Fuses 63 A 63 A n general: 100 A 63 A Pre-arcing Melting Value t s = f ( p) Operating Cut-off Value t L = f ( p, U n, cos ϕ ) Fuse 1 Fuse i i t s t L t A t t s t t L t A t A Discrimination is achieved, if: The blue area is smaller than the orange area i.e. Pre-arcing Value of fuse 1 > Operating Value of fuse Example: t s (Fuse 1) > t A (Fuse ) 100 A t s = 4000 A s t s t L 63 A = 7700 A s = A s t A = A s ZVE.ppt / / 10

11 Temperature and Diffusion as a Function of Time under Overload Conditions Te emperature [ C C] Diffusion de epth [mm] Time[s] Zeit[s] ZVE.ppt / / 11

12 Cut-off & t Characteristic The fuse limits the peak current at short circuit t Fuse 63 A 4 Circuit breaker 63 A eff ZVE.ppt / / 1

13 Peak Current and Current limitation D ka 5 ka A 63 A ka 5 eff ZVE.ppt / / 13

14 Maximum Permissable Power dissipation NH Fuse-links gg for general purpose AC 500 V and AC 690 V complying with EC Section Pa [W] A 150 A A 500 A 630 A A 400 A A 160 A 50 A AC 690 V 0 size 00 size 1 size size 3 size 4a A AC 500 V ZVE.ppt / / 14

15 Power dissipation as a Function of Load Current NH-fuse link size 00, 100 A, gg, AC 500 V e.g. P n = 6 W 1 0,9 F (Load Rel lation / n) 0,8 0,7 0,6 0,5 0,4 0,3 0, 0,1 example: P a at L = 60 A 60 A/100 A = 0,6 F(0,6) F(0,6) = 0,31 P a = F(0,6) x P n P a = 0,31 x 6 = 1,86 W 0 0 0, 0,4 0,6 0,8 1 Load Relation / n ZVE.ppt / / 15

16 Summary of Equipment Definitions Function Making and Breaking Current solating Making and Breaking Current and solating Switch Disconnector Switch disconnector Fuse combination unit Switch - Fuse Disconnector - fuse Switch-disconnector-fuse Fuse-switch Fuse-disconnector Fuse-Switch-Disconnector Utilization Category AC0B, DC0B AC1B, DC1B ACB, DCB AC3B, DC3B Typical applications Connecting and Disconnecting under no-load conditions Switching of resistive loads including moderate overloads Switching of mixed resistive and inductive loads, including moderate overloads (e.g. shunt motors) Switching of highly inductive loads (e.g. series motors) ZVE.ppt / / 16

17 Application of Fuses "gl/gg" Cable and Conductor Protection HV-Fuse Fuse Switch Combination NH-Fuse Switch Disconnector Overcurrent relay > "am" Protection of motor circuits M gtr "gtr" Transformr Transformer Protection "gr/ar" Semicond uctor Protection "gb" Mining Special Application ZVE.ppt / / 17

18 Survey of Low Voltage Fuses NH-fuses sizes: 000, 00, 1,, 3, 4 and 4a NH-fuse switch disconnectors sizes: 000, 00, 1,, 3, 4a NH-vertical fuse bases sizes: 00, 1,, 3, 4a NH- vertical fuse switch disconnectors sizes: 00, 1,, 3, 4a Rated current: Rated voltage: to 100A, to 160 A, to 50A, to 400A, to 630A, to 150A AC 400 V, AC 500 V, AC 690 V NH fuse-base 1 and 3pole NH fusw--switch disconnector 1 and 3pole Phase barrier Fuse handle NH busbar fuse-base 1-pole NH busbar fuse-switch disconnector 1-pole NH vertical fuse-base for busbar NH vertical fuse-switch disconnector for busbar systems 3-polie NH busbar fuse-base 3-pole NH fuse-switch disconnecotr for b ZVE.ppt / / 18

19 Overview of Low Voltage Fuses D0-Fuses Sizes: D01, D0, D03 Thread: E14, E18, M30x1,5 Ampere: -16A, 0-63A, A Rated. Voltage: AC 400 V DC 50 V D0- Fuse Disconnector D0- Fuse Switch Disconnector Sizes: D01, D0 Thread: E14, E18 Ampere: -16A, 0-63A Rated. Voltage: AC 400 V D-Fuses Sizes: NDz, D, D, DV Thread: E16, E7, E33, R1¼" Ampere: -5A, -5A, -63A A Rated. Voltage: AC 500 V DC 500 V D0-integral fuse-base Standard D0-Disconnector D-Einbausicherungssockel D-ntegral fuse-base Standard Screwfixing Screw fixing snap fixing D0-integral fuse-base with rail clamp D0-Load break switch slidieinsertion snap fixing D0-integral fuse-basel VBG4 D0-Load break switch screw insetrtion D-integral fuse-base for busbar D0-Busbarmounted fuse-base 3-pole D0-Busbar mounted fuse-switch-disconnector Adapter D-Busbar mounted fuse-base 3-pole D0-load breakswitch ZVE.ppt / / 19

20 EC/EN Standards EC/EN EC/HD Low Voltage Fuses : General Requirements Supplementary Requirements for fuses for use by authorized persons (mainly for industrial applications) Examples of standardized systems of fuses EC/HD Supplementary Requirements for fuses for use by unskilled persons (mainly for household applications) Examples of standardized systems of fuses EC/EN Supplementary Requirements for fuse-links for the protection of semiconductor devices ZVE.ppt / / 0

21 Practical References for Fuse Selection Selection of System EC/EN (Definition of Protection, Conditions of Electrical Network) Protection for Cable/Conductor Systems VDE 0100 T430 Selection of Fuse Rating VDE 0100 T430 Bb1 Proximity of Fuses VDE 0660 T (Rated load factors) Heat balance of the system nformation from the Manufacturer ZVE.ppt / / 1

22 System Monitoring MONTORNG Of Fuse/Switch Combinations Voltage Monitoring Fuse operation (yes/no) Switch Positionn(on/off) Current Measurement Phase Failure F1 LED-indicator System F F3 Failure Elektronic L1 L L3 Electronic Monitoring F1 F F3 Electronic-Unit A A A Relais Supply voltage 30 V / Hz N PE L Signal contact (C/O) Supply Voltage ZVE.ppt / /