Surge Arresters. UltraSIL Housed VariSTAR Station Class Surge Arresters GENERAL CONSTRUCTION

Transcription

1 Surge Arresters UltraSIL Housed VariSTAR Station Class Surge Arresters Electrical Apparatus GENERAL Cooper Power Systems has set a new standard of excellence for polymerhoused station class surge arresters. Enhancements in arrester design allow Cooper to offer increased cantilever strength and improved energy handling capability. The UltraSIL Housed VariSTAR Type US, UH, and UX Station Arresters incorporate the industry recognized superior silicone rubber housing. Cooper Power Systems Type US Arresters have passed all IEEE Standard C62.11 test requirements for station class arresters and have energy handling capability designed for most applications. UH and UX arresters also meet all test requirements for station class arresters but have higher energy handling capability for those applications which require it. TABLE 1 UltraSIL (US, UH, and UX) Station Class Ratings and Characteristics Arrester Characteristic Rating Arrester Voltage Ratings (kv) Rated Discharge Energy Single Double (kj/kv of MCOV) Impulse Impulse Rating Rating* US (3-108 kv) UH (3-108 kv) US ( kv) UX (3-108 kv) UH ( kv) System Frequency (Hz) 50/60 Impulse Classifying Current (ka) 10 High Current Withstand** (ka) 100 Pressure Relief Rating (ka rms sym.) 80 Cantilever Strength (in-ibs) MDCL- Ultimate Static*** US (3-108 kv) 15,000 6,000 UH (3-108 kv) US ( kv) 20,000 8,000 UX (3-108 kv) UH ( kv) 35,000 14,000 * Double impulse rating assumes a two shot energy discharge within one minute. ** High current, short duration withstand (100 ka, 4/10 µs) *** Maximum design cantilever load static or maximum working load is 40% of the ultimate. February 2004 Supersedes 4/99 Printed in U.S.A. Figure 1. UltraSIL Housed VariSTAR Station Class Surge Arrester family. CONSTRUCTION The unique construction of UltraSIL Housed Type US, UH and UX Class Arresters begins with world class Metal Oxide Varistor (MOV) disks produced at our dedicated manufacturing facility in Olean, NY. By manufacturing our own disks we maintain a strict quality control over the entire production process, from initial raw material inspection to final physical and electrical testing of each disk. In addition, by controlling the manufacturing process of both disks and arresters, we achieve the optimal combination. Cooper Power Systems produces MOV disks of unsurpassed quality through continuous improvements in disk formulation and manufacturing technology. The end result is a long history of in-service use with outstanding durability and protective capability. Arrester production begins by stacking glass-collared MOV disks in series with aluminum end electrodes. Our proprietary process wraps the assembly with a high-strength woven fiberglassreinforced epoxy composite. When cured, the arrester module is capable of withstanding extreme electrical and cantilever load conditions. The UltraSIL silicone rubber housing utilizes an interference fit and is bonded onto the internal module to form a 1

2 UltraSIL Housed VariSTAR Station Class Surge Arresters UltraSIL SILICONE RUBBER HOUSING ALUMINUM ELECTRODE ALUMINUM ALLOY MOUNTING BASE Figure 2. Illustration of 10 kv UltraSIL Housed VariSTAR Station Class Arrester. solid, void-free, high-dielectric strength insulation system. Once the housing is in place, each arrester must pass a strict series of electrical tests to insure the highest level of in-service performance. The silicone rubber housing results in lighter weight than similarly rated porcelain housed arresters. The silicone rubber housing is also less sensitive to physical damage than porcelain. Also, when compared to other polymeric housing materials, silicone rubber generates significantly lower external power losses under contaminated conditions. FEATURES The UltraSIL silicone rubber housing was selected for its superior insulation performance as compared to other polymeric housing materials. Long term environmental testing has verified the lifetime performance advantage that silicone rubber provides. Independent laboratory tests have verified the superior water repellent behavior of silicone rubber, which is responsible for the lower external power losses, higher resistance to UV degradation and surface tracking, superior performance in contaminated environments, and other important insulating properties. Also, UltraSIL ALUMINUM ELECTRODE FIBERGLASS REINFORCED EPOXY COMPOSITE MOV DISKS STAINLESS STEEL NAMEPLATE silicone rubber has been proven not to support biological growth and is non-flammable. The basic silicone rubber housed arrester can be customized with a variety of terminal and mounting options which allow users to select the features that meet their application needs. Customers who require longer creepage housings can easily select a different housing option through the catalog numbering system. See pages 8-9 for a complete list of available options. OPERATION The operation of the UltraSIL Housed Type US, UH, and UX Arrester is typical of gapless metal oxide arresters. During steady-state conditions, lineto-ground voltage is applied continuously between the line and ground terminals of the arrester. When surges occur, the arrester immediately limits, or clamps, the overvoltage condition by conducting the surge current to ground. After passage of the surge, the arrester returns to its initial state, conducting minimal leakage current. This minimal leakage current (which is primarily capacitive, with a small resistive component) can be tolerated on a continuing basis. The UltraSIL Housed Type US, UH, and UX Arresters easily surpass the minimum fault current withstand requirements for station class arresters as defined in IEEE C (40 ka). These arresters have been tested and shown to withstand fault currents of 80 ka. During these tests, the silicone rubber housing ruptures without expelling internal parts. UltraSIL Housed Type US, UH, and UX Arresters are ideal for protection against repeated high energy switching surges and provide reliable protection for substation equipment, capacitor banks, multiple lines, and cable circuits. They are also ideal for applications where lighter weight and shorter heights (when compared to porcelain housed arresters) are critical. DESIGN TESTING The housing, internal components, and hardware of an arrester must work together as a system. This system must stand up to years of service while being subjected to a wide range of environmental and electrical stresses. To ensure a superior level of performance, both arrester components and finished arresters have been subjected to a series of tests that accurately represents years of exposure to actual field conditions. This testing far exceeds the requirements of industry standards. The UltraSIL Housed Arrester has also met or exceeded all requirements for station class arresters as defined by IEEE C A certified test report is available upon request. For a copy, please order Cooper Power Systems document CP PRODUCTION TESTS Cooper Power Systems has implemented a complete production test program to ensure a quality product. Each MOV disk is subjected to a series of electrical tests to maintain quality. We also perform additional tests on every MOV disk batch. Listed below are the tests performed on the MOV disks: 100% Physical Inspection 100% Discharge Voltage Test 100% V ref at 6 ma 100% Watt Loss Measured at 1.05 x MCOV 100% Transmission Line Discharge Energy Test Batch High-Current, Short-Duration Test Batch Thermal Stability Test Batch Aging Test 2

3 Each fully assembled UltraSIL Housed Station Class Arrester also must pass the following production tests: 100% Physical Inspection 100% V ref Test 100% Watt Loss Test 100% Partial Discharge Inception Voltage Test GENERAL APPLICATION RECOMMENDATIONS The rating of an arrester is the maximum power-frequency line-to-ground voltage at which the arrester is designed to pass an operating duty-cycle test (as defined in IEEE C62.11 ). Table 2 provides a general application guide for the selection of the proper arrester rating for a given system voltage and grounding configurations as outlined in IEEE C62.22, which is the application guide for metal oxide surge arresters. Under fault conditions and other system anomalies, higher than normal voltages can be imposed upon an arrester. With an improper arrester selection, these abnormal system voltages can cause an arrester to fail. To help ensure that the proper arrester is selected, Cooper Power Systems application engineers are available to make recommendations. The following information is normally required: 1. Maximum system operating voltage. 2. System grounding conditions; A. For four-wire circuits, grounding conditions depend upon whether the system is multi-grounded, whether it has a neutral impedance and whether common primary and secondary neutrals are used. B. For three-wire circuits, grounding conditions depend upon whether the system is solidly grounded at the source, grounded through neutral impedance at the source transformers or ungrounded. 3. Available Fault Current. 4. Maximum line-to-ground voltage and overvoltage duration during fault conditions. Contact your Cooper representative to have your individual system application needs reviewed. TABLE 2 Recommended Arrester Applications for VariSTAR Station Class Arresters VOLTAGE PER UNIT MCOV System Voltage Recommended Arrester Rating (MCOV) () Three-Wire or Four-Wire Wye Delta and Solidly Grounded Ungrounded Nominal Maximum Neutral Wye (2.55) 3 (2.55) (2.55) 6 (5.10) (5.10) (5.10) 9 (7.65) (5.10) 9 (7.65) 10 (8.40) (7.65) 12 (10.2) 10 (8.40) 15 (12.7) (7.65) 15 (12.7) 10 (8.40) 18 (15.3) (8.40) 15 (12.7) 12 (10.2) (8.40) 15 (12.7) 12 (10.2) 18 (15.3) (12.7) 24 (19.5) 21 (17.0) 27 (22.0) (15.3) 24 (19.5) 21 (17.0) 27 (22.0) (15.3) 24 (19.5) 21 (17.0) 27 (22.0) (22.0) 36 (29.0) 30 (24.4) 39 (31.5) (29.0) 48 (39.0) 39 (31.5) (42.0) 72 (57.0) 60 (48.0) (70.0) 108 (84.0) 96 (76.0) (84.0) 132 (106) 120 (98.0) 144 (115) 120 (98.0) 144 (115) (106) 168 (131) 144 (115) 172 (140) 228 (180) (144) 240 (190) 192 (152) PRIOR DUTY NO PRIOR DUTY 60 C AMBIENT TEMPERATURE MAXIMUM TIME DURATION IN SECONDS Figure 3. Temporary overvoltage curve 60 ambient temperature. 3

4 UltraSIL Housed VariSTAR Station Class Surge Arresters TEMPORARY OVERVOLTAGE (TOV) WITHSTAND ABILITY The UltraSIL Housed Type US, UH, and UX Arresters ability to withstand 60 Hz overvoltage conditions (TOVs) is shown in Figure 3. The graph illustrates the time an arrester can survive a voltage, and recover, without going into thermal runaway, for a given voltage magnitude (expressed in Per Unit of arrester MCOV). The graphs in Figure 3 illustrate TOV withstand ability, with and without prior duty. The prior duty curve is based upon absorption of rated energy (Refer to Table 1 Single Impulse Rating) immediately preceding application of the overvoltage. MOUNTING INFORMATION The standard base of the UltraSIL Housed Type US, UH, and UX Arresters is designed for mounting on 8.75" or 10" diameter bolt circle patterns. The three slotted mounting holes are spaced 120 from each other and are designed to handle 0.5" diameter bolts. Mounting hardware (bolts, nuts, and washers) is not included with the arrester. See Figure 4 for mounting base details. An inherently strong design allows these arresters to be mounted in a variety of ways. They can be mounted vertically, with attachment at the base, or suspension (underhung) mounted. In order to underhang the arrester the proper orientation of the mounting base is required. UltraSIL Housed Station Arresters can also be horizontally mounted through 120 kv. Please select the proper mounting arrangement option in the catalog number as shown in Table 7, (on Page 8) digit 13. THICKNESS OF MOUNTING FEET IS 1.25" Figure 4. Mounting base details. 120 TYPICAL (3) 0.56" x 1.18" MOUNTING SLOTS 8.75" 10.00" DIA. BOLT CIRCLE B B C C B Figure 5. Three-phase In-line mounting arrangement. SPACING REQUIREMENTS Figure 5 illustrates a three-phase in-line mounting arrangement. Dimensions B and C reference minimum phase-toground and phase-to-phase distances respectively. These dimensions are listed in Table 8 on Page 10. NAMEPLATE INFORMATION A stainless steel nameplate is attached to the base of every UltraSIL Housed Type US, UH, and UX Arrester. The arrester catalog number, serial number, year of manufacture, duty-cycle rating, MCOV ratings, and pressure relief rating are among the details provided on the nameplate. For multi-unit arresters above 120 kv, an additional OLEAN, N.Y. USA VariSTAR SURGE ARRESTER Cat. No. Ser. No. Year Rating/Ur MCOV/Uc rms Pres. Relief ka sym. Class Cert. Frequency Alt Ft Hz M Figure 6. Detail of base nameplate. OLEAN, N.Y. USA VariSTAR SURGE ARRESTER Cat. No. Ser. No. Unit F MCOV/Uc Unit E MCOV/Uc Unit D MCOV/Uc Unit C MCOV/Uc Unit B MCOV/Uc Unit A MCOV/Uc Figure 7. Detail of unit nameplate on base. nameplate is provided on the base as shown in Figure 7. See Figure 6 for an example of a blank nameplate. TABLE 3 Catalog Numbers for Standard Configuration Type US, UH and UX Surge Arresters Arrester Rating Type US Type UH Type UX (kv, rms) 3 US003A UH003A UX003A 6 US006A UH006A UX006A 9 US009A UH009A UX009A 10 US010A UH010A UX010A 12 US012A UH012A UX012A 15 US015A UH015A UX015A 18 US018A UH018A UX018A 21 US021A UH021A UX021A 24 US024A UH024A UX024A 27 US027A UH027A UX027A 30 US030A UH030A UX030A 33 US033A UH033A UX033A 36 US036A UH036A UX036A 39 US039A UH039A UX039A 42 US042A UH042A UX042A 45 US045A UH045A UX045A 48 US048A UH048A UX048A 54 US054A UH054A UX054A 60 US060A UH060A UX060A 66 US066A UH066A UX066A 72 US072A UH072A UX072A 78 US078A UH078A UX078A 84 US084A UH084A UX084A 90 US090A UH090A UX090A 96 US096A UH096A UX096A 108 US108A UH108A UX108A 120 US120A UH120A 132 US132A UH132A 138 US138A UH138A 144 US144A UH144A 162 US162A UH162A 168 US168A UH168A 172 US172A UH172A 180 US180A UH180A 192 US192A UH192A 198 US198A UH198A 204 US204A UH204A 216 US216A UH216A 228 US228A UH228A 240 US240A UH240A 4

5 TABLE 4 Protective Characteristics of the UltraSIL Housed Station Class Arrester Type US Front-of-wave Maximum Discharge Voltage (kv crest) Switching Surge Arrester Arrester TOV* Protective 8/20 µs Current Wave Protective Level*** Rating MCOV () Level** (kv crest) () () 1 sec 10 sec (kv Crest) 1.5 ka 3 ka 5 ka 10 ka 20 ka 40 ka 125 A 250 A 500 A 1000 A * Temporary overvoltage with prior duty energy surge. ** Based on a 10 ka current impulse that results in a discharge voltage cresting in 0.5 µs. *** µs rise time current surge. ORDERING INFORMATION Table 3 includes the standard catalog numbers for UltraSIL Housed Type US, UH, and UX Arresters. The arrester represented by the standard catalog number is configured with the connectors and mounting arrangement shown in Figure 8, Page 11. The standard catalog numbers shown in Table 3 represent the same catalog numbers shown in Table 7, if the standard housing code is used in digits 9 and 10, and if 45 are used in digits 11 and 12. For example, catalog number US060A from Table 3 represents the same catalog number US A11 from Table 7. Cooper Power Systems offers other options that allow customers to select specific features they desire. Options on housing sizes (creepage length), hardware, and mounting options are available and defined in Table 7. This table allows customers who prefer options different from those in our standard Figure 8 configuration to develop a catalog number which provides the unique features they desire. For additional assistance please contact your Cooper Power Systems sales representative. PROTECTIVE CHARACTERISTICS All UltraSIL Housed Type US, UH, and UX Arresters provide excellent overvoltage protection for electrical equipment. The specific protective characteristics for each arrester rating are shown in Table 4 for US arresters, Table 5 for UH arresters and Table 6 for UX Arresters. These tables are on Pages 5, 6 and 7. 5

6 UltraSIL Housed VariSTAR Station Class Surge Arresters TABLE 5 Protective Characteristics of the UltraSIL Housed Station Class Arrester Type UH Front-of-wave Maximum Discharge Voltage (kv crest) Switching Surge Arrester Arrester TOV* Protective 8/20 µs Current Wave Protective Level*** Rating MCOV () Level** (kv crest) () () 1 sec 10 sec (kv Crest) 1.5 ka 3 ka 5 ka 10 ka 20 ka 40 ka 125 A 250 A 500 A 1000 A * Temporary overvoltage with prior duty energy surge. ** Based on a 10 ka current impulse that results in a discharge voltage cresting in 0.5 µs. *** µs rise time current surge. 6

7 TABLE 6 Protective Characteristics of the UltraSIL Housed Station Class Arrester Type UX Front-of-wave Maximum Discharge Voltage (kv crest) Switching Surge Arrester Arrester TOV* Protective 8/20 µs Current Wave Protective Level*** Rating MCOV () Level** (kv crest) () () 1 sec 10 sec (kv Crest) 1.5 ka 3 ka 5 ka 10 ka 20 ka 40 ka 125 A 250 A 500 A 1000 A * Temporary overvoltage with prior duty energy surge. ** Based on a 10 ka current impulse that results in a discharge voltage cresting in 0.5 µs. *** µs rise time current surge. 7

8 UltraSIL Housed VariSTAR Station Class Surge Arresters TABLE 7 UltraQUIK Catalog Numbering System for UltraSIL Housed Station Class Arresters U 1 1 Catalog Number Digits: 1 = U (UltraSIL Housed Arrester) { S = Standard Energy Handling (3.4 kj/kv MCOV) 2 = H = High Energy Handling (5.6 kj/kv MCOV) X = Xtra-High Energy Handling (8.9 kj/kv MCOV) 3 through 8 = Arrester Rating: Duty-cycle (MCOV) = 3 kv (2.55 kv) 9 and 10 = Housing Code (Select from Table below): = 6 kv (5.1 kv) = 9 kv (7.65 kv) Optional Housing = 10 kv (8.4 kv) Arrester Standard Housing Codes* Rating Code (Extra Creepage) = 12 kv (10.2 kv) = 15 kv (12.7 kv) = 18 kv (15.3 kv) = 21 kv (17.0 kv) , = 24 kv (19.5 kv) , = 27 kv (22.0 kv) or = 30 kv (24.4 kv) , 18 or = 33 kv (27.0 kv) = 36 kv (29.0 kv) , 18 or = 39 kv (31.5 kv) , 20 or = 42 kv (34.0 kv) , 22 or = 45 kv (36.5 kv) , 22 or = 48 kv (39.0 kv) , 24 or = 54 kv (42.0 kv) or = 60 kv (48.0 kv) = 66 kv (53.0 kv) , 26 or = 72 kv (57.0 kv) , 26, 28 or = 78 kv (62.0 kv) , 28 or = 84 kv (68.0 kv) or = 90 kv (70.0 kv) or = 96 kv (76.0 kv) = 108 kv (84.0 kv) = 120 kv (98.0 kv) = 132 kv (106 kv) = 138 kv (111 kv) = 144 kv (115 kv) , 48 or 50 50, 52 or = 162 kv (130 kv) , 52 or = 168 kv (131 kv) , 54 or = 172 kv (140 kv) , 56 or = 180 kv (144 kv) = 192 kv (152 kv) = 198 kv (160 kv) = 204 kv (165 kv) , 80 or = 216 kv (174 kv) , 82 or = 228 kv (180 kv) , 82 or = 240 kv (190 kv) or or A4 A6, A8 or B0 198 A8 B0, B2 or B4 204 B0 B2, B4 or B6 216 B4 B6, B8 or C0 228 B6 B8 or C0 240 C0 * Consult factory for additional housing codes, if required. Creepage Distance (in.) Housing Code US UH UX A A A A A B B B B B C

9 = Line Terminal Options 4.72 " (120 mm) 4.72" (120 mm) 1 = Eyebolt Connector 4 = NEMA Four-hole Pad Accepts copper or aluminum Accepts copper or aluminum conductors conductors from.16" dia. (#6) to from.16" dia. (#6) to 1.15" dia. (1000 MCM).575" dia. (250 MCM) (Standard Option) 12 = Ground Terminal Options 2.5" (6.4 mm) 3.6" (91 mm) 2.0" (51 mm) 2.5" (6.4 mm) 1 = Clamp Style Connector 5 = NEMA Four-hole Pad 9 = Eyebolt Connector Accepts copper or aluminum Accepts copper or aluminum conductors Accepts copper or aluminum conductors conductors from.16" dia. from.16" dia. (#6) to.82" dia. (500 MCM) from.16" dia. (#6) to (#6) to.575" dia. (250 MCM) (Standard Option).575" dia (250 MCM) 13 = Mounting Arrangement A = Mounting Base Located on Bottom (Standard Option) C = Mounting Base Located on Top (Suspension Mount) 14 = 1 15 = 1 9

10 UltraSIL Housed VariSTAR Station Class Surge Arresters TABLE 8 Creepage Distances and Insulation Withstand Voltages of UltraSIL Housed Station Class Arresters Insulation Withstand Voltages Creepage 1.2/50 Switching 60 Hz, dry 60 Hz wet Arrester Arrester Distances Impulse Surge Impulse 60 seconds 10 seconds Rating MCOV (inches) (kv, crest) (kv, crest) (kv, rms) (kv, rms) (kv, rms) (kv, rms) US UH UX US, UH or UX US or UH US, UH or UX US, UH or UX N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A

11 TABLE 9 Dimensions, Clearance Requirements, and Weights of UltraSIL Housed Station Class Arresters (Standard Configuration) Figure 5, Figure 5, Figure 8 Dim. B Min. Dim. C Min. Figure 8 Arrester Arrester Dim. A Phase-Ground Phase-Phase Dim. D Weight Rating MCOV (inches) Clearance (inches)* Clearance (inches)* (inches) (lbs.) (kv, rms) (kv, rms) US or UH UX US UH UX US UH UX US UH UX US UH UX * Phase-to-Ground clearances are expressed as minimum arrester centerline-to-ground distances. Phase-to-Phase clearances are expressed as minimum arrester centerline-to-centerline distances. 11

12 UltraSIL Housed VariSTAR Station Class Surge Arresters.37" (9.3 mm) 4.72" (120 mm).37" (9.3 mm) 4.72" (120 mm) 11.37" (289 mm) 11.37" (289 mm) 4.72" (120 mm) Dia. 26" (660 mm) Dia. 26" (660 mm) A 4.72" (120 mm) A A A Dia. D Dia. D Dia. D Dia. D 1.25" (32 mm) ARRESTER RATING 3-60 kv 1.25" (32 mm) kv 1.25" (32 mm) kv 1.25" (32 mm) kv Figure 8. Outline drawing of standard UltraSIL Housed Station Class Arresters (for standard catalog numbers see Table 3). ADDITIONAL INFORMATION S UltraSIL Housed VariSTAR Station Class Surge Arrester Installation and Maintenance Instructions. CP-9811 UltraSIL Housed VariSTAR Type US, UH and UX Station Class Surge Arresters Certified Test Report. Cooper Power Systems ISO 9001: 2000 Cert. # ISO 9001:2000 Olean, N.Y Cooper Industries, Inc. VariSTAR is a registered trademark of Cooper Industries, Inc. UltraSIL is a trademark of Cooper Industries, Inc. IEEE Standard C and IEEE Standard C62.22 are trademarks of the Institute of Electrical and Electronics Engineers, Inc Hickory Street Pewaukee, WI MI 2/04