IS 9836 (1981): ExplodersDisclosure to Promote the Right To Information
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IS 9836 (1981): Exploders [ETD 22: Electrical Apparatus for Explosive Atmosphere]
IS : 9836 - 1981
Electrical Apparatus for Explosive Atmospheres Sectional Committee, ETDC 22
Chairman DR G. N. BADAMI
Members
SHRI MAHEW CHANDRA ( Alternate to Dr G. N. Badami )
SHRI AMLENDU RAY Food Corporation of India, New Delhi SHRI V. THIAGARAJAN ( Alternate )
SHRI J. H. BHOJWANI Bharat Heavy Electricals Ltd, Hyderabad SHRI S. B. C AGARWAL ( Alternate I ) SHRI G. H. SAHA ( Alternate II )
SHRI S. K. BISWAS ( GUPTA ) Directorate General of Mines Safety, Dhanbad SHRI N. K. SEN ( Alternate )
SHRI P. K. CHAKRABOR~Y Indian Oil Corporation Ltd ( Refineries Division), New Delhi
SHRI S. KANUN~~ ( Alternate ) Sum S. CHANDRA Macneill & Magor Ltd Industries Division,
Calcutta SHRI A. K. HAZRA ( Alternate )
SHRI B. A. CHEESY Electronics Commission, New Delhi SHRI S. G. DEWMUKH Bharat Bijlee Ltd, Bombay
SHRI P. N. JASUTKAR ( Alternate ) DIREC-WR ( COMMERCIAL ) Central Electricity Authority, Ministry of Energy,
( Department of Power ) DEPUTY DIREC’IDR ( Alternate)
SHRI S. N. GHOSH The Association of Mining, Electrical and Mechanical Engineers, U. K., Indian Sub
SHRI S. N. GHOSH SHRI D. P. GUPTA
SHRI H. N. GUPTA
Branch,. Calcutta Siemens lndla Ltd. Bombay Directorate General of Technical Development,
New Delhi Directorate General Factory Advice Service and
Labour Institutes, Bombay SHRI G. VAIDYANATHAN ( Alternate )
DR HARIHAR SINGH Directorate of Standardization, Ministry of Defence (DGI)
( Continued on page 2 )
@ Copyright 1981 INDIAN STANDARDS INSTITUTION
This publication is protected under the Indian Copyright Act ( XIV of 1957 ) and reproduction in whole or in part by any means except with written permission of the publisher shall be deemed to be an infringement of copyright under the said Act.
IS : 9836 - 1981
( Continuedfrom page 1 )
Representing
SHRI I. M. KHUSHU ( Alternate ) Tariff Advisory Committee, Bombay
SHRI S. LAL Indian Drugs and Pharmaceuticals Ltd, New Delhi SHRI G. L. CHAWLA ( Alternate )
SHRI M. M. MEHTA Tata Consulting Engineers, Bombay SHRI R. C. BAJPAI ( Alternate )
SHRI 1. N. MURTY Chief Controllerate of Explosives, Government of India, Nagpur
SHRI CHARANJIT LAL ( Alternate ) SHRI T. NITYANANDA S. Loss Prevention Association of India Ltd, Bombay SHRI S. V. OZARDE Crompton Greaves Ltd, Bombay DR M. S. PADBIDRI Hindustan Brown Boveri Ltd, Bombay
SHRI N, SUNDARARAXAN ( Alternate ) SHRI M. A. J. PARTHASARATHY Directorate of Standardization, Department of
Defence Production, Ministry of Defence. ( Eng-in-Chief Branch )
MAJ T. R. GULATI ( Alternate ) SHRI S. G. RAMACHANURA Kirloskar Electric Co Ltd, Bangalore
SHRI T. V. VIUYARATHNA RAJ ( Alternate ) SHRI B. RAMACHANDRAN Larsen & Toubro Ltd, Bombay
SHRI I. C. JOSEPH ( Alternate ) SHRI K. P. SINGH National Hydro-electric Power Corpn Ltd,
New Delhi SHRI A. N. SRIVATHSA NGEF Ltd, Bangalore
SHRI S. L. SRIDHARAMURTKV ( Alternate ) SHRI SURESH KUMAR The Fertilizer ( Planning & Development ) India
Ltd. Sindri ~, -~ ~~ SHRI G. S. SINGH ( Alternate >
SHRI R. N. TARAFDAR Central Mining Research Station ( CSIR ). Dhanbad
SHRI S. K. RAY ( Alternate ) SHRI M. B. TAWADEY Coal India Ltd, Ranchi
SHRI A. S. R. MURTHY ( Alternate ) SHRI G. N. THADANI Engineers India Ltd, New Delhi
SHRI S. KASTHURIRANGAN ( Alternate ) DR K. S. UPPAL Explosives Safety Group, Directorate of Arma-
ments. Ministry of Defence I R & D ) SHRI R. SRINIVASAN ( Alternate )
SHRI S. P. SACHDEV. Director General, ISI ( Ex-officio Member ) Director ( Elec tech )
Secretary
( Continued on page 10 )
0. FOREWORD
0.1 This Indian Standard was adopted by the Indian Standards Institution on 27 April 1981, after the draft finalized by the Electrical Apparatus for Explo- sive Atmospheres Sectional Committee had been approved by the Electro- technical Division Council. 0.2 The exploders or blasting machines are used for blasting operations in mining and civil works ( non-mining ) areas. 0.3 There are two types of exploders, namely, permitted type and general (or non-permitted ) type used in the blasting operations. 0.4 The permitted type exploders [see also 3.1 (a) ] are used in under- ground locations where flammable gas hazard may be present. Such locations are coal mines, non-coal mines or underground civil works. Such exploders shall be approved by statutory authority before use. The general type exploders are used in the open areas where gas hazard may not be present. 0.5 It is essential that the exploder must fire the specified number of deto- nators in series and/or in parallel in a manner recommended by the manufac- turer of the exploder and in accordance with stipulations of the statutory authorities.
0.6 Attention is invited to the fact that the manufacture and use of exploders in underground coal mines is controlled by the Directorate General of Mines Safety, Dhanbad.
The testing facility, at present is available in the Central Mining Research Station, Dhanbad. 0.7 For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test, shall be rounded off in accordance with IS : 2-1960*. The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard.
1. SCOPE
1.1 This standard covers the requirements of exploders and portable blasting machines used for electric shot firing operations for activating electro-
*Rules for rounding off numerical values ( revised ).
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IS:9836-1981
2. DEFINITIONS
2.0 For the purpose of this standard, the following definitions shall apply.
2.1 Electra-Explosive/Pyrotechnic Device - A device which uses electrical energy for activating an explosive/pyrotechnic.
3. CLASSIFICATIONS
3.1 The exploders covered by this standard shall be either of the following two types:
Permitted Type - A type which is approved by the statutory authority namely, Directorate General of Mines Safety, for use in underground coal, gassy non-coal mines and other hazardous locations.
General or Non-permitted Type - A type which is used for mining operations in open places or civil work where the danger from flammable gases is not present.
4. CONSTRUCTION AND GENERAL REQUIREMENTS
4.1 The exploder shall be so constructed that all parts are of satisfactory strength for the service intended. The enclosure case shall be robust such that meets the requirements of 8.4 and 8.5, splash proof and dust tight ( degree of protection IP 54) in accordance with IS : 2147-1962*.
The enclosure of the permitted type exploders shall be so constructed as not to give rise to ignition hazard of gas and coal dust due to frictional spark, static charges and leakage current.
4.2 Carrying Strap - A carrying strap shall be fastened securely to the body of the exploder. The carrying strap shall be of adequate strength so as to withstand an additional 50 percent weight of exploder for 15 minutes with- out failure or break.
4.3 The operating spindle shall extend through the top or side of the enclosure and shall be operated by a suitable detachable handle or key. The protruding portion of the operating spindle shall be enclosed within-a
*Specification for degrees of protection provided switchgear and controlgear.
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IS : 9836 - 1981
shouder or a collar so designed that the operatings pindle cannot be opera- ted without the handle or key. The operating handle shall be proportioned and dimensioned so as to permit the operator a firm grasp without striking the knuckles during the twisting or turning movement.
4.4 The output terminals shall be provided with suitable connecting devices for firm connections. It shall not be possible to remove the connecting device from its position. It shall be possible for easy and firm connection of shot firing cable with the terminals.
4.5 The firing circuit of the exploder shall be adequately insulated from its enclosure and shall meet the requirements given in 8.1.
4.6 It shall not be possible to remove the handle or key of exploder until this is brought to ‘oh? position or the completion of firing sequence. The operat- ing handle or key shall be of special design to avoid the operations by unauthorised persons.
4.7 The exploder can be so constructed that:
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b)
It shall be operated by a removeable handle or key,
The firing circuit is made or broken either automatically or by the operation of handle or key or a push button switch, and
No residual energy is left at the terminals after the completion of operation sequence. ’
4.8 The permitted type exploders shall have suitable devices so as to termi- nate the output energy pulse within four milliseconds of the operation of the firing switch/key.
4.9 If the exploder incorporates a circuit testing device for testing the electrical continuity or resistance of the firing circuit, this device shall comply with the requirements given in Appendix A.
4.10 Each exploder shall be capable of firing prescribed number of electro- explosive/pyrotechnic detonators in the manner reco.mmended by the manu- facturer of the exploder with a total resistance appropriate to that number of shots. The performance requirements of the exploder shall be in accordance with 6.
4.11 In the case of a battery operated exploders, it shall be possible to replace the battery without disturbing or damaging components or circuit connections:
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lS:9836- 1981
4.12 The permitted type exploder shall also meet the following require- ments:
a) The exploder of the capacitor discharge/electronic type, suitable means shall be provided to ensure automatically that current is put to line only when the full output potential of the machine has been attained and also to give a clearly visible indication when the machine has attained its full output energy.
b) The exploder whose output is directly obtained from a hand operated generator, suitable means shall be provided to ensure automatically that current is not put to the line until the speed of rotation attained by the generator is at least that capable of producing the output required by 6.2 or otherwise ensuring that the output is not available until the moment of firing.
c) The exploder whose output is directly obtained from a spring driven generator, shall be provided with such measure as to ensure auto- matically that current is not put to line until full energy of the machine is attained.
4.13 Electrical Connections - All internal electrical connections shall be mechanically secured or soldered or brazed such that the exploder meets the requirements of drop test and impact test ( see 8.4 and 8.5 ).
4.14 Open-Circuit Voltage ( Peak ) ( Applicable to Multi-Shot Exploder ) - The value of maximum or peak open circuit voltage across output terminals of the exploder is under consideration.
5. MATERIALS
5.1 Materials - Materials not specifically designated shall be of a good commercial quality.
6. PERFORMANCE REQUIREMENTS
6.1 The performance of electrical exploders for successful firing of any particular number of shots connected in series and/or in parallel would depend on the characteristics of detonators used and the conditions under which the shots are fired.
6.2 The exploder shall be capable of firing the prescribed number of shots of detonators in a manner recommended by the manufacturer of the exploder.
6.2.1 The exploder manufacturer shall indicate in the instruction manual, the total circuit resistance and the rated ac and equivalent dc output voltage at that resistance.
6.2.2 In the case of capacitor type exploders, the value of capacitance, the maximum charged voltage and the external resistance shall be specified in the
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instruction manual. In addition, the total available energy/ohm/ms from the exploder may also be specified therein.
6.3 The compliance of the exploder with the requirements of this standard shall be checked by firing the specified number of detonators in a manner indicated in the instruction manual. The performance may also be checked by incorporating suitable external resistance across the output terminals.
7. MARKING
7.1 Each exploder shall be marked with the following information on its rating plate:
a) Name of the manufacturer;
b) Type of exploder; c) Rated load resistance;
d) Current in amperes; e) The rated number of detonators, the exploder would fire in series
and/or in parallel; and
f) Any other marking indicating the approval from the statutory authority.
7.2 Each exploder shall be provided with an instruction manual giving necessary operating instructions, illustrations, testing instructions, and safety precautions to ensure proper operation and maintenance of the exploder.
7.3 The exploder may also be marked with the IS1 Certification Mark.
NOTE - The use of the IS1 Certification Mark is governed bv the provisions of the Indian Standards Institution (Certification Marks) Act and the Rules and Regulations made thereunder. The IS1 mark on products covered by an Indian Standard conveys the assurance that they have been produced to comply with the requirements of that standard under a well-defined system of inspection, testing and quality control which is devised and supervised by ISI and operated by the producer. ISI marked products are also continuously checked by IS1 for conformity to that standard as a further safeguard Details of conditions, under which a licence for the use of the IS1 Certi- fication Mark may be granted to manufacturers or processors, may be obtained from the Indian Standards Institution.
8. TESTS
8.0 AcceptanceTests and the Sampling Plan - The acceptance tests and the sampling plan for exploders shall be as agreed to between the manu- facturer and the user.
8.1 Insulation Resistance Test - The exploder shall be kept for 24 hours in the humidity cabinet maintained at 27 f 2°C and relative humidity not less
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IS:9836-1981
than 95 percent. The insulation resistance of the exploder after humidity treat- ment shall be measured by insulation tester with a dc voltage of approximately 500 volts, applied between the line parts and the metal enclosure. The measurement being made one minute after the application of voltage. The insulation resistance so measured shall be not less than 50 megohm.
8.2 Dielectric Strength Test - The exploder shall be capable of withstand- ing the application of high voltage applied for one minute between mutually insulated circuits and between insulated circuits and external metal parts. The test voltage is given in the Table 1.
TABLE 1 TEST VOLTAGE
(1) (2)
up to 12 200
Over 12 and up to 15 1 Over 15 and to 25 up J 600 Over 25 and up to 50 1 Over 50 and to 100 up > 2 500 Over 100 and up to 200 J
After the high voltage test, the exploder shall meet the requirements given in 6.
8.3 Mechanical Endurance Test - All exploders shall be capable of with- standing a minimum of 5 000 actuations at the rate not less than 6 operations per minute. The exploders after the mechanical endurance test shall comply with the requirements given in 6.
8.4 Drop Test - position and
A completely assembled exploder shall be held in any then dropped once from a height of 1 m on to a concrete floor.
This test may be repeated for severe1 positions with separate exploders as desired by testing authorities before the grant of approval.
8.4.1 After the drop test, the exploder shall be checked for the require- ments given in 8.5.2.
8.5 Impact Test - The mechanical strength of the enclosure of the exploder shall be tested by the impact of falling body having a hardened steel hemi- sphere of 25 mm diameter on the impinging end. The mass of this falling body shall be 1 kg which shall be dropped vertically from a height of 2 m. The falling body shall be aimed at the weakest points of enclosure. The exploder enclosure shall be subjected to this test when placed on a rigid base. After
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IS:9836-1981
the test it shall satisfy the requirements given in 8.5.2 and also the dust tightness requirements of IP 54 in accordance with IS : 2147-1962*.
8.5.1 The strength of the transparent parts of the exploder shall be tested by the impact of a falling body having on the impinging end a hemisphere of 25 mm diameter in polyamide ( nylon 6.6 ) rockwell hardness R 100. The mass of the falling body shall be 1 kg which shall be dropped vertically from a height of 1 m. The transparent parts are tested when the exploder is placed on a rigid base.
8.5.2 The impact test and drop test ( 8.4) shall not produce a condition which invalidates the type of protection of the enclosure of electrical apparatus. Any deformation caused by these tests shall not prevent the proper operation of the electrical apparatus nor reduce the creepage and clearance distances nor the degree of protection of the enclosure. It is accepted that the superficial damage, chipping to paint work, breakage of cooling fans or similar parts of the electrical apparatus and small items shall be ignored.
APPENDIX A ( Clause 4.9 )
REQUIREMENTS FOR CIRCUIT CONTINUITY TESTER
A-O. Before firing the detonators with exploder, it is required to check the continuity of the firing circuit with a resistance measuring device. It is better to measure the circuit resistance to be of the order for the particular number of shots. If the resistance is high and the firing is continued there may be misfire. To avoid this, there should be a check over the measurement of continuity and circuit resistance.
A-l. While doing so the testing current in the circuit should be as low as possible not exceeding 50 mA so that the detonators may not be fired while checking the continuity of shots. The circuit of the continuity tester shall be intrinsically safe conforming to IS : 5780-1980t.
A-2. The instrument shall be so designed and constructed as to be incapable of firing even a single detonator in the circuit.
A-3. The construction and the enclosure of the continuity tester shall meet the similar requirements as applicable to exploders. ( see 4, 8.4 and 8.5 ).
*Specification for degrees of protection provided by enclosures for low-voltage switchgear and controlgear.
tSpecification for intrinsically safe electrical apparatus and circuits (first revision ).
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IS:9836-1981
Members
Representing
Directorate General of Mines Safety, Dhanbad
SHRI B. K. SHARAN ( Alternate to Shri V. C. Varma j
SHRI J. ACHARI SHRI SARAL DAS (Alternate)
SHRI S. SESHAN
Indian Explosives Ltd. Calcutta SHRI K. R. KRISHNASWAMY ( Alternate )
SHRI R VEDAM IDL Chemicals Ltd, Hyderabad SHRI P. V. SATYAVRATAN ( Alternate )
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