A Revolution in Energy System.
"Make in India Policy"
: Drop Out (D.O.) Fuse Elements:
‘Mayur’ Brand D.O. Fuse elements
11/22 and 33 KV D.O. fuse units,
Use in 11/22 KV electricity distribution lines, transformer centers by all electricity Boards/ electricity company and by Railway Department for Electric traction railway lines.
"Mayur" D.O. Fuse Element
(11KV Transformer Center With 3 D.O. Gang isolators included 3 D.O. Fuse elements)
Drop Out (D.O.) Fuse Elements:
We are manufacturing ‘Mayur’ Brand Fuse elements for 11/22 KV and 33 KV D.O. fuse units for electricity distribution network of India.
Use by: * All States electricity Boards/electricity company of India.
* Indian Railway Department.
Advantages of these Fuse Elements:
* It is cheapest form of operation.
* It affords current limiting effect under short circuits conditions due to cut off.
* It requires minimum time to replace.
* It requires no maintenance.
* It has current limiting effect.
Manufacturing range & Models:
Our ‘Mayur’ brand D.O. Fuse elements are available for 11/22 KV & 33 KV D.O. fuse units from 3.0 Amp to 70 Amp with models A & B.
Model A: New Standard:
Model:(A) New Standard
This model (A) having overall length is 24.5 inch with flexible tinned copper wire rope of 49 wires each of 38 SWG at both sides for fixing with D.O. unit. This model (A) provided 6 inch long protective SRBP tube to avoid fixing difficulty on D.O. on electric pole. This is economy model. This model is very easy to use with existing D.O. 'Langer' wire system. This model is also best for replacement of D.O. 'Langer' wire system for Indian & South Asian rural electricity distribution. This model (A) is hot demand in rural distribution area. For your inquiry/purchase Contact us.
This model (B) having overall length is 24.5 inch with provided 8.0 inch long of protective SRBP tube with flexible tinned copper wire rope of 49 wires each of 38 SWG at both sides for fixing with D.O. unit. This model is suitable for High Voltage expulsion type D.O. fuse units. They are inserted through the carrier tube. This is standard D.O. Fuse Element model for standard D.O. units.
At present, few areas in India, line staff are using this models directly as 'Langer' wires in open D.O., but getting difficulty to hook on bottom terminal of open D.O., facing obstacle problems by SRBP Tube some excess length. To avoid fixing problem of these standard fuse elements, we has innovated our 'Mayur' (A) models for rural electricity distribution system in India.
As per our 35 years experience, we suggest to use our standard (B) model for standard D.O. units only and remaining (A) model for existing Indian & South Asian rural open D.O. system for replacement of 'Langer' D.O. wire.
Best Suggested Rating for our Indian existing rural area:
Transformer KVA …………....... Rating of D.O. Fuse Element
25 KVA……………………........................ 03 Amp according to local area load condition.
63 KVA………………………...................... 03 Amp according to local area load condition.
100 KVA………………………...................... 05 to 10 Amp according to local area load condition.
200 KVA……………………........................ 10 to 15 Amp according to local area load condition.
500 KVA……………………........................ 20 to 30 Amp according to local area load condition.
Feeder Tap line (500 KVA load)........ 40 Amp according to local area load condition.
Feeder Tap line (800 KVA load)........ 60 Amp according to local area load condition.
Feeder Tap line (1000 KVA load)....... 80 Amp according to local area load condition.
Feeder Main line .............60 Amp to 100 Amp (According to connected load)
IS 9385/ 80-III advice to replace all three Fuse Elements links at a time while on replacement of any one melted fuse elements, unless it is definitely known that over current has passed through that unmelted fuse elements.
In fluctuating load transformer, fuse elements should allow the short time over current to flow without blowing. For this, it is necessary to select fuse Elements of rated current greater than that of the transformer, i.e. 2 or 3 times rated current is best selection for fluctuating load.
Your Local Purchase:
Please send us your local purchase inquiry/Tender: Contact Us
General Technical Information:
High Voltage expulsion type D.O. fuse are used extensively for the protection of feeders and transformers. ‘Mayur’ Fuse elements are suitable for High Voltage expulsion type D.O. fuse units. They are inserted through the carrier tube and hold the switch in its latcoed position while they are intact. When the fuse element melts, the latcoed trigger is released and allows the switch to swing down to the isolated position.
(11KV single Phase Transformer center with D.O. Fuse included Fuse Elements)
Avoid ‘Langer’ D.O.:
In our rural areas 11/22 KV & 33 KV and LT distribution network, our line staffs using ‘Langer’ wires instead of this D.O. fuse elements due to non availability of this item in field offices of our Electricity Board/ Vij Company. Our line staff is taking the ‘Langers’ wire from the scrap Aluminium conductors having minimum size is 2.00 mm each single wire and its rated current capacity is more than 80 Amp. The ‘Langer’ fuse wire can’t protect the 100 KVA transformers in time from over load fault conditions and resulting into burning out transformer frequently. Actually 100 KVA transformer is require 05 A or 10 A rated D.O. Fuse elements according to local area over load conditions. The substandard ‘Langer’ D.O. fuse wire is increasing overall transformers failure rate of our distribution system. We have specially designed our ‘Mayur’ D.O. Fuse Element for using in open D.O. for replacement of the substandard ‘Langer’ fuse wire systems.
We have specially designed our ‘Mayur’ DO fuse elements for using in open DO for replacement of substandard ‘Langer’ fuse wire with 3 different A, B, & C models.
What is main function of D.O. Fuse Elements?
The main function is to breaks power circuit within calculated/stipulated time while passing calculated overload in Distribution Transformer/Feeder Tap lines. We must think on this main function as our ‘Langer’ system is fulfilling this function? In India, on average, 99 % of Distribution Transformers and Feeder Tap lines are operating with substandard ‘Langers’ D.O. system. In this situation, we must have to concentrate our full attention to improve this substandard D.O. ‘Langers’ system. In this regards, a strong circular is issued in 1982 by Mr. Mankodi, Cheif Engineer, GEB, Baroda with main subject line of "Avoid Lungers of Transformers Centers."
‘Mayur’ Fuse Elements Technology:
(Reference books, A Text Book of Electrical Technology for electrical engineers by S.L. Bhatia and B.L. Theraja)
Fuse Element:-It is that part of the fuse which melts when an excessive current flows in the circuit and thus isolates the device from the supply mains.
Current Rating of Fuse Element:-It is that value of current at which the fusing elements can normally carry without melting. Its value is less than the minimum fusing current.
Minimum fusing current: It is that minimum value of current at which the fuse element melts.
Fusing Factor: It is the ratio of the minimum current at which a fuse element will blow to its rated current.
Fusing Factor= minimum fusing current / rated current.
It is always greater than unity and is equal to 1.9 to 2.0 for DO Fuse Elements.
Example: A 5 amp fuse element will operate when current through it exceeds 5A *1.9 = 9.5A for a sufficient length of time.
Effects on Fuse Element:
(1) Oxidation of fuse element wire and consequent thinning of fuse wire section with laps of time.
(2) Local heating caused by loose connection.
(3) Effect of weather in proximity.
(4) Single phasing effect
It is to be noted that a wire taken out a cable is not fit to be used as a fuse element and should, therefore, be not used for the purpose.
Heat Generation: The maximum heat is generated at central portion of fuse element wire when full rated current passing through and become melted before fusing time. To avoid this drawback, heat sink device must require at central portion. For heat sink device, additional small wire piece jointed together or provided additional sleeve with one turn of wire to increase thickness at central portion of element.
Length of Fuse Element wire: The minimum length of fuse element wire used must be 2 to 3 inch of central element.
Physical Construction of ‘Mayur’ Fuse elements:
Mayur’ D.O. Fuse Elements are standard electrical designed, consists of special alloy wire overlapped centrally within the heat sink device ferrule/sleeve provided to protect from over heating during full load. The fuse elements are crimped jointed by ferrule/sleeve with two stranded tinned copper flexible wire rope tails made of 38 SWG/49wires. The overall length of 11/22 KV D.O. fuse elements tails are 24.5 inch and for 33 KV D.O. fuse elements tails are 33 inch for standard model. The central portions of the Fuse Elements are having a protecting device made of good quality SRBP tubes with glossy coating.
Heat Generation: The maximum heat is generated at central portion of fuse element wire when over rated current passing through and become melted before fusing time. To avoid this drawback, heat sink device must require at central portion. For heat sink device, additional small wire piece jointed together or provided additional sleeve with one turn of wire to increase thickness at central portion of element.
SRBP Tube: D.O. Fuse Elements are having a protecting device made of good quality SRBP tubes with glossy coating. Our SRBP Tubes are manufacturing from the best quality of Electrical grade insulating papers of high temperature range with Super grade Silicone resin bonded.
Flexible Tail rope wires: The D.O. fuse elements are crimped jointed by ferrule/sleeve with two stranded tinned copper flexible wire rope tails made of 38 SWG/49wires. We are manufacturing stranded tinned copper flexible wire ropes by our own stranding machine from Electrical Grade 100% tinned copper wires.
Stranded tinned copper flexible wire ropes: 15.00 Kg Reel
:Our own Wires Stranding Machine:
Testing by Recognized Test House:
Our ‘Mayur’ D.O. fuse elements are tested as per IS: 9385/80-II by
(1) The Central Scientific Instruments Organization(C.S.I.O.), CHANDIGARH.
(2) ERDA Laboratory, Baroda.
(3) Government Engineering College, Jabalpur.
Strength test: Result: SATISFACTORY.
Tail Strength test: Result: SATISFACTORY.
Marking: Result: SATISFACTORY.
Time/Current Test: Result: SATISFACTORY.
Fuse elements Amp rating tests are conducted at 100% to 200% of rated current as per IS Standard clause 198-2-6. All fuse elements,
(1) must open at 135 to 150% Amp of rated load within 1 Hour.
(2) must open at 200% Amp of rated load within 5 minutes. If it takes more and more time,
selection of fuse elements is poor.
Our own Testing:
Our ‘Mayur’ D.O. fuse elements are tested for over load Amp breaking test, Mechanical Strength test & physical tests on random basis in our own testing laboratory, which is fully equipped with Current booster from 1 Amp to 100 Amp, Digital current meters, testing instruments.
:D.O. Fuse Element Testing Machine:
Our own testing machine
Specifications of our machine:
Input working: Single Phase 230 V A/C with manual fine tuning controller, with main switch, with Red indicator, fuse facility.
Output working: Boost Current 0 to 100 Amp A/C with manual fine tuning controller, suitable out put 2 terminals provided at back side, 4 Digit Current Meter 100/5 A CT operated.
Test Result:Current over load test, Current Breaking Test from 0 to 100 Amp possible.
Duty Cycle: 1.00 Hrs continue with 100 Amp full loads testing.
Use for: D.O.Fuse Elements Testing, Electric PVC wire testing, Fuse wire testing.
Mayur Vidyut Company
( District Industry Center Registered S.S.I. Unit No: 24 - 004 - 11 - 00522 )