482571.1 Typical Polymer-Housed Metal-Oxide Arrester
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Revision 0
May 16, 2000
1. Scope
This specification applies to gapped heavy-duty distribution class and gapless riser pole class metal-oxide surge arresters for use on a 12,470 Grd-Y/7,200 volt 60-Hz AC power distribution system. The arresters shall be configured similar to the above illustration.
2. Application
The arresters will be used predominantly on primary underground cable riser poles. To a lesser extent they will be used on selected primary overhead equipment poles.
3. Reference Standards
Except as modified by this specification, the arresters shall be constructed, tested and furnished according to the latest revision of ANSI/IEEE Standard C62.11. If a conflict exists between the referenced standard and this specification, this specification shall prevail.
4. Material ID Number
This specification applies to District Material ID No. 482571.
5. Construction and Materials
Arresters shall be either gapped metal-oxide or gapless metal-oxide type. Arresters shall be suitable for crossarm mounting with a standard NEMA crossarm mounting bracket; however, they shall be supplied without a crossarm mounting bracket. Arrester housings shall be made of a nonfragmenting polymeric material. Arrester studs and end caps shall be stainless steel.
6. Terminals
Arresters shall be equipped with stainless steel line (top) and ground (bottom) terminals. Line terminal hardware shall include a stainless steel wire clamp, stainless steel or silicon bronze terminal nut and polymeric animal guard cover. Ground terminal hardware shall include a stainless steel wire clamp and stainless steel or silicon bronze terminal nut.
7. Ground Lead Isolator
Arresters shall be equipped with a ground lead isolator to effectively disconnect the ground lead from the arrester in the event of arrester failure or damage.
8. Color
Arresters shall be ANSI No. 70 Sky Gray in color.
9. Ratings
The arrester shall have the following ratings:
| Duty Cycle Voltage - RMS | 10kV |
| Maximum Continuous Operating Voltage (MCOV) RMS | 8.4kV |
| Impulse Test 1.2/50 msec Full Wave Crest kV BIL (min.) | 75kV |
| Lightning Impulse Classifying Current | 500A |
| Switching Surge Classifying Current | 10,000A |
| Housing Leakage Distance (min.) | 14.0 in. |
10. Discharge Voltage - Current Characteristics
The discharge voltages of the arrester shall not exceed the maximum values specified below at the test currents shown:
| Test Current (kA) | Maximum Discharge Voltage kV Crest Using an 8/20 microsec Current Wave |
|---|---|
| 1.5 | 24.0 |
| 3.0 | 25.0 |
| 5.0 | 26.0 |
| 10.0 | 27.0 |
| 20.0 | 31.0 |
| 40.0 | 37.0 |
11. Temporary Over Voltage Capability
The minimum temporary overvoltage (TOV) capability of the arrester, without prior duty, shall be as specified below:
| Duration (seconds) | Voltage P.U. of MCOV |
|---|---|
| 1.0 | 1.38 |
| 10 | 1.29 |
| 100 | 1.24 |
| 1000 | 1.10 |
12. Identification
An identification nameplate according to ANSI/IEEE C62.11-1999, Section 10.1, shall be made an integral part of each arrester.
13. Packaging
Arresters shall be individually packaged in cardboard cartons with all of their accessories to prevent damage during transporting and handling. The line and ground terminal hardware shall be assembled to the arrester. Each individual carton shall be legibly marked with the manufacturer's name and the arrester type, voltage rating and catalog number.