TECHNICAL SPECIFICATION FOR LT PIN/SHACKLE INSULATORS

Transcription

1 TECHNICAL SPECIFICATION FOR LT PIN/SHACKLE INSULATORS SEAL & SIGNATURE OF THE TENDERER PAGE 1 OF 11

2 TECHNICAL SPECIFICATION FOR LT PIN/SHACKLE INSULATORS 1.0 Scope : The specification covers the manufacture, testing at works supply and delivery of procelain Insulators for overhead power lines with a nominal voltage below 1000 volts. Nothe pin and shackles type insulators are covered. 2.0 Climatic conditions : The insulators specified herein shall be suitable for outdoor use under the following climate conditions. 2.1 Maximum ambient temperature (Degree C) Maximum temperature in shade (Degree C) Minimum temperature of Air in shade (Degree C) Relative Humidity (Percent) to Maximum annual rain fall (mm) Maximum wind pressure (kg/sq.m) Maximum altitude above mean seal level (meter) Isoceranic level (days per year) Seismic level (Horizontal Acceleration) g 1.10 Moderately hot and humid tropical climate Conductive to trust and fungus growth 3.0 System : 3.1 The insulators will be installed be installed on three phase 433 volts. AC & 50 HZ system in which the neutral is effectively grounded. The insulators shall be designed to work continuously at a voltage. 10% in excess of the normal rated voltage. 4.0 Design Specification : 4.1 The insulators shall confirm to provisions under IS : or its latest version in all respects. The dimensions of the insulators are as per Drawing No The Pin insulators shall be threaded to take mild steel pin of dimensions given below : SEAL & SIGNATURE OF THE TENDERER PAGE 2 OF 11

3 Pin Insulator Type - 1 Suitable for Head Shank Steel Threads as per profile of threads as insulators as given in Fig.5 of IS : 1445/1977 Dia. 16 mm Remarks Pin Insulators threads as per profile given in Fig.5/1445/ The design of the insulators shall be such that stress due to expansion and contraction in any Part of the insulators shall not lead to its deterioration. 4.3 The insulators shall be suitable for use with all Aluminium Conductor or copper conductor or ACSR up to 100 mm sq. The insulators should withstand the conductor tension the reversible wind lead as well as the high frequency vibrations set due to wind. 5.0 Insulation Characteristics : 5.1 The insulators shall have the electrical and mechanical characteristic given in the table below : Type of Insulators Power frequency flashover Voltage in KV (RMS One minute power frequency with stand voltage in KV (RMS) Power frequency puncture withstand voltage KV (RMS Dry Wet Dry Wet Pin x the actual flashover voltage Minimum failing load kg Shackle (Type Type - 2) 6.0 General Requirements : 6.1 The porcelain used in the manufacture shall be sound free from defects, thoroughly vitrified and smoothly glazed. 6.2 The glaze on the insulators shall generally to White/Cream Brown except for the screw threads and the parts on which the porcelain is supported during fittings, which may be left unglazed, all other surfaces of the insulators shall be efficiently glazed. 6.3 The insulators shall be in one piece. The pin type shall a top groove and shall have dimensions as shown in the drawing. 6.4 The insulators shall be marked properly in accordance with clause 6 of ISS : SEAL & SIGNATURE OF THE TENDERER PAGE 3 OF 11

4 7.0 Testing facilities : The tenderer must clearly indicate what testing facilities are available in the works of the manufacturer and whether the facilities are adequate to carry out all the routine as well as type tests. These facilities should be made available to Board s Engineers if deputed to carry out or witness should be made any tests cannot be carried out at the manufacturers works, the reasons should be clearly stated in the tender. 8.0 Tests : The insulators shall be tested in accordance with the procedures detailed in IS : 1445/1977 which are reproduced below : 8.1 Routine Tests : 8.2 Type Tests : Type tests shall be made on the insulators that has passed the routine tests. For requirements of insulators up to 2000 no. One insulators shall be selected for the type test mentioned below. However, maximum no. of insulators to be tested in the lot shall be limited to twenty to twenty numbers only. a) Dry one minute power frequency À Withstand test & dry flash over test À As per IS: 1445/1977 b) Wet one minute power frequency À withstand and wet flash over test À As per IS : 1445/ Acceptance tests : The number of insulators for the acceptance tests mentioned below shall be selected at random from the lot in accordance with the table below : Lot size Sample size of Insulators Up to to to to to above The insulators, after having withstand the routine test shall be subjected to the following tests in the order given below : SEAL & SIGNATURE OF THE TENDERER PAGE 4 OF 11

5 a) Verification of dimensions À b) Temperature cycle test À As per IS : 1445 c) Mechanical failing load test À d) Power frequency puncture withstand test À e) Porosity test À The insulators selected in accordance with 8.3 shall be up to two equal parts and subjected to the tests indicated. Tests Part of sample a) & b) Both Parts c) & e) First Part d) Second Part 9.0 Rejection : 9.1 Criteria of conforming and Rejection : If only one insulators fails to comply with any one of the tests given in (a) to (b) a fresh quantity equal to twice the first quantity shall be subjected to retesting. The retesting shall comprise the test in which the failure occurred preceded by house, test which may be considered to have influenced the results of the original tests if no failure occurs, the lot shall be accepted. 9.2 It two or more insulators fail to comply with any sample tests given in (a) to (d) or if any failure occurs on insulators subjected to retesting described in 8.2, the complete lot shall be withdrawn for further examination by the manufacturer after which the lot of any part thereof may be resubmitted for tests. 9.3 The number then selected shall be three times the first quantity chosen for tests. This testing shall comprise the test in which the failure occurred proceeded by those test which may be considered to have influenced the results of the original test. If failure occurs the last lot shall be rejected. Insulators which do not conform to the requirements of 8.1 and 8.2 shall be rejected Test Certificates : 10.1 Along with the tender, the tenderer shall submit the test certificate for all routine, type and sample tests specified above If required, the board shall subject the consignment of insulators supplied to the aforementioned test. The testing under this clause will be carried out in any laboratory including boards own laboratory. Notice of such tests will be given by the Board to the supplier by ordinary post. However, the date of testing will not be postponed or altered at the request of the supplier. The supplier is at liberty to be present during this test. SEAL & SIGNATURE OF THE TENDERER PAGE 5 OF 11

6 11. Marking : As per IS : 1445/ Packing: All insulators shall be packed in suitable double gunny bags and shall be transported by road. 13. Inspection : The Board may be depute an Engineer to witness the routine and sample tests at their manufacturers works for which advance intimation shall be given the manufacturers whenever a lot is ready for dispatch. 14. Schedule : The tenderer shall fill in the following schedule which is part and parcel of the tender specification and offer. If the schedules are not submitted duly filled in with the offer, the offer shall be liable for rejection. Schedule A - Guaranteed technical particulars Schedule B - Schedule of deviation Schedule C - Tenderer s experience Schedule D - Schedule of deviation form Specification standards Schedule E - Deviation from specified test Requirements. Unless otherwise brought out separately by the tenderer in the schedule of deviations (Schedule B, D & E ) for this item offered shall be deemed to confirm to the specification scrupulously. All deviations from the specification shall be brought out in the Schedules of deviation (Schedule B, D & E ). The discrepancies between the specification and the catalog or literature submitted as part of the offer shall not be considered as valid deviation unless specifically brought out in the schedule of deviation as stated above. SEAL & SIGNATURE OF THE TENDERER PAGE 6 OF 11

7 SCHEDULE A GURANTEED TECHNICAL PARTICULARS The guaranteed technical particulars as given below shall be furnished. 1. TYPE OF INSULATORS: 2. APPLICABLE IS ; 3. SYSTEM VOLTAGE AND FREQUENCY 4. CONFIRMATION TO DRAWING NO: POWER FREQUENCY FLASHOVER VOLTAGE (DRY) 6. POWER FREQUNCY FLASHOVER VOLTAGE (WET) 7. ONE MINUTE POWER FREQUENCY WITHSTAND VOLTAGE (RMS (DRY) 8. POWER FREQUENCY WITHSTAND VOLTAGE (RMS) (WET) 9. POWER FREQUENCY PUNCTURE WITHSTAND AND VOLTAGE 10. MINIMUM FAILING LOAD 11. TYPE TEST REPORTS ENCLOSED : YES OR NOT. 12. PACKING 13. NET WEIGHT OF ONE INSULATORS SEAL & SIGNATURE OF THE TENDERER PAGE 7 OF 11

8 SCHEDULE - B SCHEDULE OF DEVIATIONS FROM SPECIFICATION SR.NO. CLAUSE NO. DETAILS OF DEVIATION NAME OF FIRM NAME & SIGNATURE OF THE TENDERER DESIGNATION DATE SEAL & SIGNATURE OF THE TENDERER PAGE 8 OF 11

9 SCHEDULE C SCHEDULE OF TENDERER S EXPERIENCE Tenderer shall furnish here a list of similar orders executed/under execution by him to whom a reference may be made by Purchaser in case in considers such & reference necessary. Sr.No Name of Client & Description order Value of Order Period of supply & commissioning Name & address to whom reference may be made NAME OF FIRM NAME & SIGNATURE OF TENDERER DESIGNATION DATE SEAL & SIGNATURE OF THE TENDERER PAGE 9 OF 11

10 SCHEDULE D SCHEDULE OF DEVIATIONS FROM SPECIFIED STANDARDS SR. Particulars Stipulation of Specified Standards Standard Ref. Stipulation Stipulation of standard adopted by terderers Standard Stipulation Ref. Remarks NAME OF FIRM NAME & SIGNATURE OF TENDERER DESIGNATION DATE SEAL & SIGNATURE OF THE TENDERER PAGE 10 OF 11

11 SCHEDULE E DEVIATION FROM SPECIFIED TEST REQUIREMENTS SPECIFIED IN RELEVANT AND PRESENT SPECIFICATIONS Sr. No. Name of Test Standard No. & Clause No. Requirement of Standard Proposed deviation Reasons for deviation NAME OF FIRM NAME & SIGNATURE OF TENDERER DESIGNATION DATE SEAL & SIGNATURE OF THE TENDERER PAGE 11 OF 11