CATALOG NUMBER 081 LOCKE SUSPENSION INSULATORS BALTIMORE, MARYLAND
LOCKE SUSPENSION S S N INSULATORS S GUIDE TO SELECTION OF LOCKE SUSPENSION INSULATORS M&E Strength BALL & SOCKET TYPE CLEVIS TYPE Without Zinc Sleeve With Zinc Sleeve Shed Diameter x Spacing Without Zinc Sleeve Shed Diameter x Spacing (ANSI Class) (ANSI Class) (Leakage Distance) (ANSI Class) (Leakage Distance) 20K 20S840 (52-3) 20S195 (52-3) 10 x 5 3/4 (12 5/8 ) 20S580 (52-4) 10 x 5 3/4 (12 5/8 ) 30K 30S255 (52-5) 30S295 (52-5) 10 x 5 3/4 (12 5/8 ) 30S257 (52-6) 10 x 5 3/4 (12 5/8 ) 40K 40S360 (52-8) 40S370 (52-8) 10 x 5 3/4 (12 13/16 ) 40S290 (52-10) 10 x 6 1/2 (12 13/16 ) 50K --- CA589MZ* (52-11) 11 x 6 1/8 (15 15/16 ) CA589Q* (52-12) 11 x 7 (15 15/16 ) *We offer 50,000 lb M&E insulators under NGK part numbers. Please reference NGK catalog No. 14C. 1
LOCKE INSULATORS, INC. SUSPENSION INSULATORS LOCKE SUSPENSION INSULATORS Today s insulators provide even greater benefits and reliability than in the past. Locke suspension insulators are designed and manufactured to give unparalleled performance and reliability. Silent testimony to this fact is the continuing function of the millions of units already in service. Although shapes and appearances seem unchanging, today s insulators provide even greater benefits and reliability than in the past. Special features and performance capabilities have been added which significantly assist the transmission line designer. CONSTRUCTION DETAILS
1. CONNECTIONS 4. PORCELAIN SHELLS Insulators are furnished with either ball-and-socket or clevis-eye configurations. The ability for either style to be connected with other similar insulators is assured by conformance to ANSI standards. Routine checks are made with gages. 2. COTTER KEYS Positive locking of both types is attained by using a humped-type cotter key to prevent unintentional uncoupling during service or handling. The ball-and-socket design has enjoyed a greater popularity over the years because of the overall flexibility and the lack of loose parts. The self-contained split cotter key, by virtue of its hump, can be maintained in either the locked or unlocked position. 3. CAPS & PINS Caps are manufactured of malleable iron or ductile iron. Pins are forged steel. Caps and pins are galvanized per ASTM A153. Proven manufacturing techniques provide the finest quality porcelain to ensure uniformly high mechanical and electrical strength. Each class of insulator has been designed with the unique configurations required to develop the required electrical and mechanical performance. All exposed surfaces are glazed to provide a smooth hard finish, which is easily cleaned of contaminants, and which significantly enhances the mechanical strength. Glaze-bonded sand surfaces on the porcelain provide reliable gripping areas for the cement to develop the full strength of the insulator. 5. ASSEMBLY & TEST Assembly of hardware and porcelain is made with Alumina cement, which has superior characteristics over the Portland cement which is normally used. The cement is steam-cured under controlled conditions to achieve optimum physical properties. Each insulator is mechanically proof-tested at 50% of its M&E rating and is electrically tested prior to shipment. A permanently flexible coating on the inside of the cap and on the pin protects the cap and pin from chemical attack by the cement. The coating also provides more uniform distribution of working stresses in the insulator components. 6. MARKING & COLOR Each porcelain shell is permanently marked to show the manufacturer name, year of manufacture, M&E Strength and Proof-Test Value which has been applied to the insulator. Insulators are available in the following glaze colors: light gray, dark gray, royal blue, and brown. 3
LONG TERM STRENGTH Experience shows that Locke suspension insulators maintain their mechanical strength over long periods of time without deterioration. This performance results from using properly engineered materials, good design, and modern manufacturing equipment and technology. We think that it is important to be able to substantiate that our insulators do indeed have long-term strength. We have established an in-house specification to use the IEC Publication 60575, Thermal-Mechanical Performance Test and Mechanical Performance Test on String Insulator Units, as a design test for all Locke suspension insulators. This test consists of simultaneously applying a mechanical cyclical load and a thermal cyclical environment to the insulators. After four cycles, the insulators are subjected to an M&E test. We feel that the M&E results obtained after cyclical stressing of the insulators should be substantially the same as the M&E results obtained without cyclical testing. LOKGARD SLEEVE All Locke ball and socket suspension insulators can be equipped with Lokgard sleeves where pin corrosion has been or is expected to be a problem. Serious pin corrosion can result from electrolytic action with the most severe activity apparently related to areas having high levels of contamination. Corrosion can take place totally outside of the cement which results solely in loss of pin cross-section and hence mechanical strength. Or it can take place inside the cement causing bursting pressure to the porcelain shell with subsequent catastrophic electrical and mechanical failure. The Lokgard sleeve is high purity zinc that is cast on to the insulator pin prior to assembly. It too will corrode in service at approximately the same rate as the steel in the pin, but until the zinc is consumed, no corrosion of the steel can occur. Additionally, the zinc oxidizes without residue, and cannot build up the larger expansion volume in the manner of rusted steel. Therefore, it is impossible for a Lokgard protected insulator porcelain shell to be subjected to corrosion-caused hoop stress damage. A substantial amount of data obtained on a variety of designs by many manufacturers shows a remarkable correlation with extended field performance Designs that perform well on this test have performed very well in service whereas those designs that perform poorly have demonstrated generally unsatisfactory field performance. Contact your local sales representative for design reports covering Long-Term Tests. 4
20,000 lb. M & E CHARACTERISTICS Catalog Number 20S840 20S580 Cat. No. w/lokgard Sleeve 20S195 - ANSI Class 52-3 52-4 M&E Rating, lb. 20,000 20,000 Leakage Distance in. 12 5/8 12 5/8 Dry Arcing Distance, in. 7 9/16 7 9/16 Mechanical Impact Strength, in.-lb. 100 100 Tension Proof, lb. 10,000 10,000 Low Frequency Flashover Dry, kv 80 80 Wet, kv 50 50 Critical Impulse Flashover Pos., kv 125 125 Neg., kv 130 130 Low Frequency Puncture, kv 110 110 Radio influence Voltage Data Test Voltage, RMS to Ground, kv Max. RIV 10 10 at 1000 khz, uv 50 50 Net Weight Each, lb. 10.6 12.1 Standard Package Quantity 6 6 Packed Weight, lb. 78 82 20S840 ANSI CLASS 52-3 20S580 ANSI CLASS 52-4 5
30,000 lb. M & E CHARACTERISTICS Catalog Number 30S255 30S257 Cat. No. w/lokgard Sleeve 30S295 - ANSI Class 52-5 52-6 M&E Rating, lb. 30,000 30,000 Leakage Distance in. 12 5/8 12 5/8 Dry Arcing Distance, in. 7 9/16 7 9/16 Mechanical Impact Strength, in.-lb. 100 100 Tension Proof, lb. 15,000 15,000 Low Frequency Flashover Dry, kv 80 80 Wet, kv 50 50 Critical Impulse Flashover Pos., kv 125 125 Neg., kv 130 130 Low Frequency Puncture, kv 110 110 Radio influence Voltage Data Test Voltage, RMS to Ground, kv Max. RIV 10 10 at 1000 khz, uv 50 50 Net Weight Each, lb. 11.7 12.1 Standard Package Quantity 6 6 Packed Weight, lb. 84 82 30S255 ANSI CLASS 52-5 30S257 ANSI CLASS 52-6 6
40,000 lb. M & E CHARACTERISTICS Catalog Number 40S360 40S290 Cat. No. w/lokgard Sleeve 40S370 - ANSI Class 52-8 52-10 M&E Rating, lb. 40,000 40,000 Leakage Distance in. 12 13/16 12 13/16 Dry Arcing Distance, in. 7 11/16 7 11/16 Mechanical Impact Strength, in.-lb. 100 100 Tension Proof, lb. 20,000 20,000 Low Frequency Flashover Dry, kv 80 80 Wet, kv 50 50 Critical Impulse Flashover Pos., kv 125 125 Neg., kv 130 130 Low Frequency Puncture, kv 110 110 Radio influence Voltage Data Test Voltage, RMS to Ground, kv Max. RIV 10 10 at 1000 khz, uv 50 50 Net Weight Each, lb. 14.7 15.4 Standard Package Quantity 6 6 Packed Weight, lb. 97 102 40S360 ANSI CLASS 52-8 40S290 ANSI CLASS 52-10 7
STRING FLASHOVER CHARACTERISTICS (Based on ANSI 29-1 Test Procedures) Disc Dia. x Spacing Number of Units 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Dry 380 440 495 545 600 650 700 745 795 840 880 925 965 1005 1045 1080 1120 1155 1190 1220 1255 1285 1320 1350 1380 10 x 5 3/4 Low Frequency Flashover kv Wet 240 280 320 360 400 440 480 520 560 600 640 680 720 760 805 845 885 925 965 1005 1045 1085 1125 1165 1205 Positive 560 640 720 800 880 960 1040 1120 1200 1280 1360 1440 1520 1600 1680 1760 1835 1915 1995 2075 2155 2235 2315 2395 2475 Critical Impulse Flashover kv Negative 575 660 745 825 910 995 1080 1165 1250 1335 1420 1505 1590 1675 1760 1845 1925 2010 2095 2180 2265 2350 2435 2520 2605 Dry 425 490 550 610 665 720 775 825 875 920 970 1015 1055 1100 1140 1180 1215 1255 1290 1325 1360 1395 1425 1460 1490 10 x 6 1/2 Low Frequency Flashover kv Wet 270 315 365 410 455 500 545 590 635 680 725 770 815 860 905 950 1000 1045 1090 1135 1180 1225 1270 1315 1360 Positive 625 715 805 895 985 1075 1165 1255 1345 1435 1525 1615 1705 1795 1885 1975 2065 2155 2245 2335 2425 2515 2605 2695 2785 Critical Impulse Flashover kv Negative 640 735 830 925 1020 1120 1215 1310 1405 1500 1595 1690 1785 1885 1980 2075 2170 2265 2360 2455 2550 2650 2745 2840 2935 8
SALES OFFICES NGK-LOCKE INC. (BALTIMORE OFFICE) 2525 Insulator Drive Baltimore, Maryland 21230, U.S.A. Tel: +1(410) 347-1700 Fax: +1(410)347-1724 Email: NLBALT@ngkus.com NGK-LOCKE INC. (ATLANTA OFFICE) 1880 West Oak Parkway Suite 104 Marietta, Georgia 30062, U.S.A. Tel: +1(404) 659-3153 Fax: +1(678) 303-1374 Email: NLATL@ngkus.com NGK-LOCKE INC. (DALLAS OFFICE) 1452 Hughes Road Suite 200 Grapevine, Texas 76051, U.S.A. Tel:+1(817) 410-5789 Fax:+1(817) 796-2290 Email: NLDA@ngkus.com NGK-LOCKE INC. (LOS ANGELES OFFICE) 21250 Hawthorne Blvd., Suite 500 Torrance, California 90503, U.S.A. Tel: +1(310) 316-3323 Fax: +1(310)316-3944 Email: NLLA@ngkus.com NGK INSULATORS OF CANADA, LTD. (TORONTO OFFICE) 2700 Matheson Blvd. East, Suite 700 East Tower, Mississauga, Ontario L4W 4V9, Canada Tel: +1(905) 602-1266 Fax: +1(905)238-8247 Email: NCTOR@ngkus.com NGK INSULATORS OF CANADA, LTD. (MONTREAL OFFICE) 1501, Avenue McGill College, Bureau 515 Montreal (Quebec) H3A 3M8, Canada Tel: +1(514) 281-8488 Fax: +1(514)281-8596 Email: NCMON@ngkus.com BALTIMORE, MARYLAND