TURKISH ELECTRICITY DISTRIBUTION CO. TECHNICAL SPECIFICATION FOR POST (SUPPORT) INSULATORS FOR MEDIUM VOLTAGE SYSTEMS CONSULTANT: ELTEM-TEK ELECTRICAL INSTALLATIONS ENGINEERING SERVICES AND TRADE CO. JUNE, 1996
TECHNICAL SPECIFICATION FOR POST INSULATORS FOR MEDIUM VOLTAGE SYSTEMS CONTENTS 1. GENERAL 1.1. Subject and Scope 1.2. Standards 1.3. Work Conditions 2. TECHNICAL CHARACTERISTICS 2.1. Type of Post Insulators 2.2. Electrical and Mechanical Characteristics 2.3. Constructional Characteristics 2.3.1. Insulating Parts 2.3.2. Metal Parts 2.3.3. Top and Bottom Fixing Arrangements 2.3.4. Marking 2.3.5. Dimensions and Tolerances 3. TESTS 3.1. Type Tests 3.1.1. Type Tests to be Applied to the Insulators of Ceramic and Glass 3.1.2. Type Tests to be Applied to the Post Insulators of Epoxy Resin 3.2. Sample Tests 3.2.1. Sample Test to be Applied to the Post Insulators of Porcelain and Glass 3.2.2. Sample Test to be Applied to the Post Insulators of Epoxy Resin 3.3. Routine Tests 3.3.1. Routine Tests to be Applied to the Post Insulators of Porcelain and Glass 3.3.2. Routine Tests to be Applied to the Post Insulators of Epoxy Resin 3.4. Acceptance Tests and Provisions 3.4.1. Acceptance Tests and Sampling 3.4.2. Acceptance Criteria 3.4.3. Provisions for Acceptance Tests 3.4.4. Acceptance Procedure 1
4. MISCELLANEOUS CONDITIONS 4.1. Packing 4.2. Documents to be Submitted With the Bid 4.3. Documents to be Submitted for Approval 4.4. Prices 4.5. Warranty ADD I BILL OF MATERIALS ADD II SCHEDULE OF GUARANTEED CHARACTERISTICS 2
1. GENERAL 1.1. Subject and Scope This specification covers the technical characteristics of post insulators to be purchased and installed in medium voltage distribution networks with highest voltage of 36 kv. The aerial line insulators are out of the scope of this specification. The post insulators in the scope of this specification shall be supplied as complete units together with all their accessories as specified in this specification. The types and the technical characteristics of the post insulators to be purchased have been given in the Bill of Materials and/or Schedule of Guaranteed Characteristics attached to this specification. 1.2. Standards Post insulators specified in this specification shall be designed, manufactured and tested in accordance with the latest editions of the following standards. TS 556 / IEC 168 Tests on indoor and outdoor post insulators for systems with nominal voltages greater than 1000 V TS 4237 / IEC 660 Tests on indoor post insulators of organic material for systems with nominal voltages greater than 1000 V up to but not including 300 kv. TS 2042 / IEC 273 Characteristics of indoor and outdoor post insulators for systems with nominal voltage greater than 1000 V IEC 815 Guide for the selection of insulators in respect of polluted conditions. TS 6080 / IEC 437 Radio interference tests on high-volatge insulators. If any other standards with equivalent or tighter conditions are applied, an English or Turkish copy of the standard shall be submitted with the bid. 1
1.3. Work Conditions Unless otherwise specified in the Bill of Materials, post insulators to be supplied shall be suitable for operation under the service conditions listed below. SERVICE CONDITIONS INDOOR OUTDOOR - Altitude : Below 1000 m unless otherwise specified - Ambient Temperature. minimum : -25 0 C - 40 0 C. maximum : 40 0 C 45 0 C. 24 hours average : Not exceeding 35 0 C Not exceeding 35 0 C - Air Pollution level : - - Icing : - Class 10, 10 mm - Wind pressure : - 700 Pa (34 m/s wind velocity) - Average relative humidity : over 24 hours - 95 %, maximum - Earthquake. Horizontal acceleration : 0.5 g for indoor and outdoor. Vertical acceleration : 0.4 g for indoor and outdoor 2. TECHNICAL CHARACTERISTICS 2.1. Type of Post Insulators Types of the post insulators, according to their installation location and major insulation material and in accordance with the standard type definitions of IEC 273, shall be as follows; - Indoor post insulators of porcelain or glass : Type-J - Indoor post insulators of epoxy resin : Type-J0 - Outdoor cylindrical post insulators of porcelain or glass with internal metal fittings - Outdoor cylindrical post insulators of porcelain or glass with external metal fittings : Type-H : Type-C 2
2.2. Electrical and Mechanical Characteristics Unless otherwise specified in the Bill of Materials, the electrical and mechanical characteristics of the post insulators shall be as follows: - Highest system voltage (kv) : 7.2 12 17.5 36 - Dry lightning impulse withstand voltage (kv-peak) : 60 75 95 170 - One minute dry power/frequency withstand voltage (for indoor types) ( kv-rms) : 28 38 50 70 - One minute wet power-frequency withstand voltage (for outdoor types) (kv-rms) : 20 28 38 70 - Minimum nominal surface creepage distances for outdoor types (mm) :. For pollution level II (MEDIUM) (mm) : 220 240 350 600. For pollution level III (HEAVY) (mm) : 190 300 438 900 - Rated frequency (Hz) : 50 - Mechanical Withstand : As specified in the Bill of Materials (to be selected from following table) Type Failing loads (bending) (N) (Symbol) 2000 4000 6000 8000 10000 12500 16000 J X X - X - - X JO X X X X X - X H X X - X - - X C - X X X X X - NOTE: 12500 N failing load of Type C is only valid for systems having highest system voltage of 17.5 kv and 36 kv. 3
2.3. Constructional Characteristics 2.3.1. Insulating Parts - Post insulators shall have a capability to withstand and cope with all pull (tensile), torsion and bending forces prevailing under normal service conditions and in the case of over voltages and short circuits arising in the system. They shall be suitably designed and manufactured to withstand electromechanical forces earthquakes and other vibrations, sudden temperature changes, and to prevent cracks and breaks due to forces caused by elongation and contraction. - Insulating parts shall be smooth and symmetrical and shall ensure a uniform distribution of electrical field and minimization of radio interference voltage. Radio interference voltage (RIV) emitted by the insulators shall not exceed the level indicated in the IEC 437. - Under-surfaces and grooves shall be shaped to ensure self-cleaning. - Post insulators shall be free from any harmful substances, cracks, flaws, burrs, specks or other imperfections. - Post insulators shall be made of high grade insulation materials and all the exposed surfaces of the outdoor type post insulators shall be glazed smoothly in shining brown colour, they shall be manufactured so that they shall withstand temperature variations, industrial pollution, ozon, acid, alkalines, dust and other atmospheric effects. - Glass insulators shall be made from toughened lime-soda glass. - For manufacture of indoor type insulators, only epoxy resin shall be used as organic material, insulators made from other types of organic materials shall not be accepted. 2.3.2. Metal Parts All the metal parts and bolts and nuts shall be fixed in a manner so that the fixing medium shall not enter into chemical reaction with the metal parts or cause fracture by mechanical stresses and expansion due to the temperature changes. 4
All metal parts of insulators shall be made of non-corrosive metals or shall be hot-dip galvanized. Galvanizing shall comply with the TS 914/ISO 1459, 1460, 1461 standards. Thickness of galvanize coating shall be; - for iron and steel castings and forgings 600 g/m 2 for all samples, 500 g/m 2 on any individual sample - for bolts, nuts and washers 375 g/m 2 for all samples, 300 g/m 2 on any individual sample 2.3.3. Top and Bottom Fixing Arrangements - Insulators made of ceramic and glass shall be fitted with metal fittings at the top and bottom. Fittings shall be fixed so that they shall be placed and centered on the insulator axis with a right angle and such that their faces shall be in parallel position. - Dimensions, number of holes, size of threaded holes and arrangements of fittings fixed on C type insulators shall be as indicated in IEC 273 Tables IV and IV A. - J, JO and H type insulators shall be provided with one fixing hole at the center of top and bottom fittings. The sizes of the threaded holes shall be in accordance with IEC 273 Tables I, II and III. Furthermore, fittings shall be fitted with additional auxiliary holes, if it is required in the Bill of Materials. - Threads on top and bottom fixing arrangements shall be in ISO metric thread size and shall be provided in accordance with principles described in IEC 273 Clause 6. The length of full thread at the holes, shall be not less than the bolt diameter for ceramic or glass insulators, and not less than 1.5 times the nominal bolt diameter for cast epoxy resin insulators. Holes to be tapped shall be oversized by not more than 0.25 mm. Threads shall be suitable for steel bolts having standard dimensions after galvanizing. - Bidders shall submit with their bids the detailed drawings showing top and bottom fixing arrangements and sizes of the fixing holes. 5
2.3.4. Marking Each insulator shall be marked, with a permanent and clearly legible manner, with the following data; - Manufacturer s name or trademark - Data of manufacture - Type designation of the insulator (mechanical strength class, type and rated lightning impulse withstand voltage designations of the insulator, as per IEC 273, Clause 8) 2.3.5. Dimensions and Tolerances Basic dimensions of post insulators are the followings: - overall height - maximum nominal diameter of the insulating part - fixing arrangements - minimum nominal creepage distance. Dimensions of the ceramic and glass insulators shall be subject to the following tolerances: - height : as indicated in the relevant tables of IEC 273 - creepage distance : ± (0,04 d + 1,5) mm - for other dimensions ± (0,04 d + 1,5) mm when d 300 mm ± (0,025 d + 6) mm when d > 300 mm where d is the checked dimension in mm. For epoxy resin insulators, dimension other than those for which specific tolerances are specified shall be subject to the following tolerances; ± (0,01 d + 0,2) mm, where d is the dimension to be measured in mm. 6
3. TESTS 3.1. Type Tests Following type tests shall be carried out for each type of post insulators on a number of samples as required in the relevant IEC standards, such samples shall e taken from lots which have passed routine and sample tests. 3.1.1. Type Tests to be Applied to the Insulators made of Ceramic and Glass - Verification of dimensions (IEC 168, Sub-clause 5.1) - Dry lightning impulse withstand voltage test (IEC 168, Sub-clause 4.5) - Dry power-frequency withstand voltage test (applicable only to post insulators of indoor type) (IEC 168, Sub-clause 4.7) - Wet power-frequency withstand voltage test (applicable only to post insulators of outdoor type) (IEC 168, Sub-clause 4.8) - Test for mechanical strength (IEC 168, Sub-clause 5.2) - Test for deflection under load (IEC 168, Sub-clause 5.3) - Radio interference test (IEC 437). 3.1.2. Type Tests to be Applied to the Post Insulators of Epoxy Resin - Verification of dimension (IEC 660, Clause 27) - Dry lightning impulse withstand voltage test (IEC 660, Clause 15) - Dry power-frequency withstand voltage test (IEC 660, Clause 16) - Partial discharge extinction voltage test (IEC 660, Clause 17) - Lightning impulse puncture test (This test shall be applied only to post insulators of type B) (IEC 660, Clause 18) - Test for mechanical strength (IEC 660, Clause 19) - Test for deflection under load at normal ambient temperature conditions (IEC 660, Clause 20) - Test for mechanical bending strength as a function of temperature (IEC 660, Clause 21) - Water absorption test (IEC 660, Clause 22) - Wetting and moisture test (IEC 660, Clause 23) - Flammability test (IEC 660, Clause 24) - Temperature cycle test (IEC 660, Clause 25) - Dielectric loss factor (tan δ) or power factor (Cos φ) measurement. 7
3.2. Sample Tests Sample tests shall be carried out on samples selected from lots which have passed the routine tests and number of samples shall be as indicated in the Subclause 3.4.1. 3.2.1. Sample Test to be Applied to the Post Insulators of Porcelain and Glass - Verification of dimensions (IEC 168, Sub-clause 5.1) - Temperature cycle test (IEC 168, Sub-clause 5.4) - Test for mechanical strength (IEC 168, Sub-clause 5.2) - Power-frequency voltage puncture test (This test shall be applied only to post insulators of type B) (IEC 168, Sub-clause 4.9) - Porosity test (for ceramic post insulators only) (IEC 168, Sub-clause 5.6) - Galvanizing test (IEC 168, Sub-clause 5.7) 3.2.2. Sample Test to be Applied to the Post Insulators of Epoxy Resin - Verification of dimensions (IEC 660, Clause 27) - Partial discharge extinction voltage test (IEC 660, Clause 17) - Test for deflection under load at normal ambient temperature conditions (IEC 660, Clause 20) - Test for mechanical strength (IEC 660, Clause 19) 3.3. Routine Tests Routine tests which shall be applied to each post insulator by the manufacturer during the manufacturing process are the followings. 3.3.1. Routine Tests to be Applied to the Post Insulators of Porcelain and Glass - Thermal shock withstand test (for toughened glass parts only) (IEC 168, Sub-Clause 5.5) - Visual inspections (IEC 168, Sub-Clause 5.8) - Electrical routine test (IEC 168, Sub-Clauses 4.10.1 or 4.10.2) - Mechanical routine test (IEC 168, Sub-Clause 5.9) 3.3.2. Routine Tests to be Applied to the Post Insulators of Epoxy Resin - Visual examination (IEC 660, Clause 30) - Electrical routine test (IEC 660, Clause 31) 8
3.4. Acceptance Tests and Provisions 3.4.1. Acceptance Tests and Sampling Unless otherwise specified in the Contractor documents and its attachments, acceptance tests shall consist of the followings; - Type tests specified in Sub-clause 3.1. Repetition of all or some of the type tests may be requested as acceptance test. Type tests (if requested) shall be made on number of samples of each type as required by the standards. - Sample tests specified in Clause 3.2. All the sample tests shall be carried out on samples taken from each delivery lot. Out of the post insulators which are sent to inspection and test at the same time, those of the same material and type are considered as one party. The samples of post insulators shall be selected at random by the Purchaser s representatives, and unless otherwise specified, the number of samples shall be determined from the following tables according to the type of insulator. Number of insulators (ceramic or glass) in a party (n) Number of samples n 500 1 % 500 < n 4 + (1.5 n / 1000) Number of insulators (epoxy resin) in a party (n) Number of samples Less than 300 3 300 1200 1 % More than 1200 8 + (3 n / 1000) If the calculation does not give an integer number then the next greater integer number shall be chosen. 9
3.4.2. Acceptance Criteria i) Acceptance criteria for type tests All type tests shall have a positive result. For type tests which shall be carried out according to IEC 168 and IEC 660, those acceptance criteria mentioned in the relevant clauses, of these standards, indicated in Sub-clause 3.1 shall apply. For type tests which shall be carried out according to other IEC standards, acceptance criteria specified in those standards shall be applied. The negative result of a type test, if deemed by the Purchaser essential for reliable operation of insulators, may involve rejection of all the post insulators of the same type of the order. The purchaser, at its unobjectionable judgement, may accept the repetition of the test if the Supplier proposes to modify the design of the post insulators within a reasonable period of time and to repeat, at its own expense, all the type tests specified by this specification. ii) Acceptance criteria for sample tests The party shall be accepted if all the sample tests have a positive result within the tolerances if any- and/or acceptance criteria mentioned in the relevant clauses of IEC 168 and IEC 660 are met. Retest procedure which shall apply for sample tests is explained below. If only one post insulator or its metal part fails to comply with any of the sample tests, a new quantity of test samples equal twice the number of samples initially taken shall be subjected to retesting. The retesting shall comprise the test in which failure occurred, preceded by those tests which may be considered to have influence on the results of the original test. If two or more post insulators or their metal parts fail to comply with any of the sample tests or if any failure occurs on post insulators or metal parts subjected to retesting as described above, the complete party shall be withdrawn for further examination by the Manufacturer. 10
Provided the cause of the failure can be clearly identified, the Manufacturer may sort the lot to eliminate all the insulators with that defect. If party divided into small groups is concerned and if one of these groups has been rejected, then the test may be done for other groups also. The sorted lot, or part thereof, may than be resubmitted for testing. The number of test samples selected shall be three times the first quantity chosen for tests. The re-testing shall comprise the tests in which the failure occurred and preceded by those tests which may be considered as to have an influence on the result of the original test. If any failure occurs on post insulators re-submitted for tests, the complete party shall be rejected. 3.4.3. Provisions for Acceptance Tests i) In case the type test reports are not submitted with the bid or the submitted reports are found unsatisfactory as mentioned in the Contract, all or some of the type tests under Sub-clause 3.1 will be done at the manufacturer s facilities or at an independent laboratory in Turkey or abroad at the supplier s expense. If the contract stipulates performance of some type tests abroad, other acceptance tests will not start unless positive reports of the tests performed abroad are submitted to the Purchaser. The Supplier will not claim for time extension due to delays in delivery caused by performance of the type tests. No payment shall be made to the Supplier prior to obtaining the results of the acceptance tests. ii) Even if the type test reports submitted with the bid are found satisfactory or positive results are obtained from the type tests performed during acceptance tests of the first party delivery, the Purchaser, may, at its own discretion, request the repetition of all or some of type tests at the first lot delivery or later deliveries at the Manufacturer s facilities or in an independent laboratory in Turkey or abroad. The samples necessitated by the tests/standards for the type tests to be done in Turkey or abroad will be selected by the Purchaser s representatives. For the type tests to be done abroad, the sample (s) will be stamped and will be sent by the manufacturer to the laboratory where the test will be performed. 11
In case positive results are obtained from these tests, all of their costs will be paid by the Purchaser as YTL considering the type test prices given in the Contract. If the test prices are given in foreign currency, they will be converted to YTL considering the foreign currency sale rate of the Central Bank of the Republic of Turkey, valid on the test date. In case negative results are obtained from the test, all costs of the tests will be paid by the Supplier and the remaining portion of the order will be cancelled. 3.4.4. Acceptance Procedure i) The Purchaser shall have the right to inspect and to test the Goods during manufacturing or transportation at the manufacturer s or its sub-contractors premises. To enable the Purchaser s representatives to perform these inspections, the Supplier shall help them in every respect. ii) The Supplier shall submit to the Purchaser the test and inspection program after signing of the Contract. The Supplier shall notify the Purchaser at least 20 (twenty) days in advance of the active date of the beginning of the tests to be performed abroad, and 7 (seven) days in advance for the tests to be performed in Turkey. iii) It is essential to perform all of the routine and sample tests at the manufacturer s premises. During the acceptance tests, the tests which could not be performed at the manufacturer s premises, if any, shall be performed within 15 (fifteen) days of the beginning date of the acceptance tests. Otherwise, the material will not be considered as ready for delivery. The delayed test date will be accepted as the delivery date provided that the test results are submitted to the Purchaser within 7 (seven) days. However, the Purchaser reserves the right for using the delay-related provisions of the contract. iv) The tests will be performed in presence of the Purchaser s representative. In the test reports, the information about serial numbers and main parts of the sample(s) will take place and the reports will be prepared so as to clearly indicate the conformity of the material to the conditions in the contract and its annexes and then will be counter signed. If the test result is positive, the Purchaser s representative will write a Release Note for the shipment of the relevant material lot. The Purchaser may not wish to be presented at the tests by notifying the Supplier in due course. In such a case, the Supplier shall proceed with the tests and submit the test results to the Purchaser. The test reports thus prepared and signed by the Supplier shall be sent to the Purchaser in 5 copies for check and approval. If the tests reports are approved the Purchaser shall issue a Release Note for shipment and return the 1 approved copies of Test Report to the Supplier. 12
If the Purchaser s representative do not attend a test performed abroad, the sample(s) will, upon completion of the test, be sent back by restamping by the laboratory. The mentioned sample(s) will be inspected by the Purchaser s representatives at the Supplier s premises. v) The Purchaser s right to inspect, test, and where necessary, reject the Goods after the Goods arrival in the final destination shall in no way be limited or waived by reason of the Goods having previously been inspected, tested and passed by the Purchaser or its representative prior to the Good s shipment from the country of origin. vi) Fulfilling the provisions in this clause shall not in any way release the Supplier from Warranty or other obligations under the Contract. 4. MISCELLANEOUS CONDITIONS 4.1. Packing Post insulators shall be delivered as packed. Each post insulator unit shall be wrapped in kraft paper and shall be placed in a box made from corrugated cardboard or an another suitable material. Insulators shall be packed within strong cases reinforced by means of steel belts to protect them from being damaged during transportation. All boards used for crates of packing shall be made of pinewood or other similar strong timber and shall not be made of poplar or other similar wood. Wood shall be without spike knots as far as possible and wood with loose knots, decayed parts and splits shall not be used. Insulators shall be packed so that 3-6 insulators shall be placed in each case. The supplier shall submit, with the bid and later for approval of the purchaser, packing method, thickness of the boards used for packing crates, outer dimensions and transportation weights. 13
The outdoor insulators that will be considered as equivalent type regarding the electrical tests, will be made of the same material using the same method and will have the following characteristics: - Arc distance will be the same or longer - Nominal outer diameter of the insulated section will be the same or greater - Number and location of metal fixing elements will be approximaly the same - Distance between insulator guards will be the same with ± 5 % tolerance - Guard projecture length will be the same with ± 10% tolerance. - Guard profile will be the same. The insulators that will be considered as of the equivalent type for mechanical failing load test, will be manufactured at the same factory using the same material and method and will have the following characteristics: - Nominal outer diameter of the insulated section will be the same. - The design of the connection between the insulated section and metallic fixing arrangements will be the same. - Number and shape of the metallic fitting elements to be connected to the insulated section will be the same (their arrangement may be different). - Their nominal heights will be the same with ± 20% tolerance. Out of the epoxy resin insulator tests; the water absorption test, the flash test and the ageing and humidity test will be repeated if epoxy resin type is different. Although the test on temperature dependence of mechanical bending strength is basically related to the type of epoxy resin, the shapes and approximate dimensions of the tested and the equivalent insulators should be the same. Other tests will be repeated for each insulator with different material and design. If the manufacturing is done under a license, the type test report will be prepared for the manufacturing in Turkey. - Detailed drawings showing shapes, applicable tolerances and basic dimensions as per the relevant standards. - Catalogues about the production and characteristics of insulators. - Packing method, dimensions and weights of the packing cases. - ISO 9000 quality system certificate and/or Certificate of Conformity to Turkish Standards. 14
Following information shall be written on each container in a manner protected against environmental conditions; - Manufacturer s name - Purchaser s name and address - Purchaser s order number - Type of the insulator - Purchaser s material code number - Number of insulators in case - Case weight - Case dimensions 4.2. Documents to be Submitted With the Bid Following documents shall be submitted with the bid: - Schedule of Guaranteed Characteristics Bidders are required to fill in and sign the attached Schedule of Guaranteed Characteristics for each item and enclose one copy of each with their bids. Information given in these schedules will be binding. - Reports of type tests carried out in an independent laboratory The name of testing laboratory, the names, positions and signatures of the persons who performed or witnessed the test and the test date will take place in the test reports. The reports of the tests of previous orders, witnessed by the Purchaser will also be accepted. The test reports should be belong to the offered type. Therefore, the Purchaser may request the Supplier to verify that the test reports are belong to the offered type or its equivalent. 15
The Bidder s failure to submit any of the documents required herein or any missing data may entitle the Purchaser to reject the bid. The Purchaser may, to its satisfaction, consider to evaluate a bid in case of a bidder who did not submit appropriate or any type test reports, for the type tests to be performed in Turkey or abroad at the Supplier s cost, on sample(s) to be selected out of the first delivery lot for the tests that can be performed in Turkey and prior to the first party delivery for the tests that can be done abroad. 4.3. Documents to be Submitted for Approval The Supplier shall submit the following documents for approval of the Purchaser after placement of the order and within the period mentioned in the contract. - Scaled Drawings showing shapes and overall dimensions of the post insulators as per the relevant standards. - Drawings showing the symbols and values which shall be used for marking for designation of the insulators. - Drawings showing packing methods, dimensions and weights of the packing units. 4.4. Prices The Supplier shall warrant that each post insulator of the supply shall have no defect arising from design, materials or workmanship, for 24 months after the date of delivery. Should the insulators become defective or damaged due to the design; material or manufacturing errors within the warranty period, the Supplier shall replace the defective equipment in a way to the approved by the Purchaser.. At this own expense including dismantling, transportation, mounting etc. The replaced equipment shall be covered by the same warranty stipulations. 16
APP. I BILL OF MATERIALS FOR POST INSULATORS OF MEDIUM VOLTAGE SYSTEM 1. Type of the post insulator : Order No.:. ITEM NO. 1 2 3 4 - Standard designation symbol : - Indoor/outdoor : - Insulation material (ceramic, glass or epoxy resin) : 2. Highest system voltage (kv) : 3. Mechanical failing load (kgf) : 4. Pollution Level - II (MEDIUM) : - III (HEAVY) : 5. Number of auxiliary holes on the top and the bottom fittings : 6. Altitude (if above 1000 m) (m) : 7. Purchaser s material code number : 8. Quantity : 17
APP. II SCHEDULE OF GUARANTEED CHARACTERISTICS FOR POST INSULATORS of MEDIUM VOLTAGE SYSTEMS 1. Manufacturer : 2. Manufacturer s type designation : 3. Standards in force : 4. Type of post insulator : - Standard designation symbol : - Indoor/Outdoor : - Insulation material (porcelain, glass or epoxy resin) 5. Dielectric loss factor (tan δ) : (at 20 0 C, for epoxy resin only) : 6. Dry lightning impulse withstand voltage (kv-peak) : 7. Dry power-frequency withstand voltage (for indoortypes) kv-rms) : 8. Wet power/frequency withstand voltage (for outdoor types) (kv-rms) : 9. Puncture voltage - for glass and porcelain insulators (for only type B insulators) Order No. :. Item No. :. Purchaser s Material Code Number :. REQUIRED GUARANTEED : (kv) : - for epoxy resin insulators (kv) : 10. Mechanical failing load (kgf) : 11. Max.difference in deflection between 20% and 50% of the failing load (mm) : 12. Minimum nominal creepage distance (mm) : 13. Height of insulator (mm) : 14. Maximum nominal outer diameter (mm ) : 15. Net weight of insulator (kg) : 16. Gross weight (kg) : 17. Altitude (m) : 18