Tinned Copper Fuse Wire

             Tinned Copper fuse wire is one of the common and simple fuse element used in semi enclosed fuses for maintaining the safety of electric equipment. The material used is Tin plated Copper. Copper is a good conductor, has good tensile strength and corrosion resistance. Hence bare copper wire is not a bad choice to use as a fuse. But, Tin plated copper fuse wires are much popular and widely used. Why ?

Tin Plating

             When Tin plating is applied over bare copper wire, it improves the strength and longevity of the copper beneath it. The corrosion resistive power of bare copper wire to humid and wet atmospheres gradually decreases when temperatures exceed especially above 100 degrees Celsius when carrying currents. In such circumstances, Tin plating on the bare Copper wire protects Copper beneath it and improves longevity and strength of the fuse wire. Tin coating does not allow oxidation easily. Tin coating on the fuse wire also makes it convenient for soldering. Even though Tin plated Copper wire is expensive than bare Copper wire, the expenditure will be prudent in the long run usage. Hence, TC fuse wires are widely used in electrical maintenance.

Advantages of TC fuse wire

  1. It is cheapest.
  2. It requires no maintenance.
  3. It requires minimum time to replace.

Disadvantages of TC fuse wire

  1. Due to prolonged exposure to atmosphere, oxidation makes the wire thin and fails.
  2. Operation is unreliable and hence cannot be used for large fault currents.
  3. There is a chance of misuse by using inappropriate rated fuse wire.
  4. Loose connections causes local heating.

 

Specification & Ratings

The common specification of TC fuse wire is Standard Wire Gauge (SWG) in the market based on the diameter of the wire which is the main parameter to decide the current carrying capacity of the fuse wire. The current carrying capacity of a TC fuse wire is usually mentioned as ‘Rated Current‘ of the wire which indicates the maximum current that the fuse can continuously conduct without interrupting the circuit and ‘Fusing Current‘ which indicates the current at which the fuse blows isolating the equipment from the circuit.

The ratings of TC fuse wires as per IEE regulations are mentioned below for reference and practise of using correct rated TC fuse wires for the electrical equipment under protection.

TINNED COPPER FUSE WIRES

I.E.E Regulation 14th edition Table A1

Approximated size of Fuse Elements Composed to Tinned Copper wire for use in semi-enclosed Fuses.

S.W.G

Diameter in inches Rated Current‘ of fuse in amperes

Approximate ‘fusing current’ in amperes

40

0.0048 1.5 3
39 1.0052 2.5

4

38

0.0060 3.0 5

37

0.0068 3.5 6

36

0.0076 4.5 7

35

0.0084 5.0

8

34 0.0092 5.5

9

33

0.0101 6.0

10

32

0.0108 7.0

11

31

0.0116 8.0

12

30

0.0124 8.5

13

29

0.0136 10.0

16

28

0.0148 12.0

18

27

0.0164 13.0

23

26

0.0180 14.0

28

25

 0.020 15.0

30

24

0.022 17.0

33

23

0.024 20.0

38

22

0.028 24.0

48

21

0.032 29.0

58

20

0.036 34.0

70

19

0.040 38.0 81
18 0.048 45.0

106

17

0.056 65.0 135

16

0.064 73.0

166

15 0.072 78.0

197

14 0.080 102.0

230

13 0.092 130.0

295

Sample look

bfw-01