48 lines
1.9 KiB
Markdown
48 lines
1.9 KiB
Markdown
---
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title: Medium Voltage
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tags:
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- topic/construction/electrical
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- type/encyclopedia-entry
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up: "[[electrical-construction]]"
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---
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# Medium Voltage
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"Medium voltage" refers to voltage systems greater than 600V.
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## Insulation Level
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> [!example]
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>
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> > [!cite] 343 Madison Avenue Project Specifications, emphasis added
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> > 2.2 MEDIUM VOLTAGE CABLES (CON EDISON)
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> > * ...
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> > * H. Construction
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> > * ...
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> > * 3. Insulation
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> > * ...
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> > * c. _The minimum average insulation thickness shall be not less than 175 mils._
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> > The minimum thickness at any cross-section of the insulation
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> > shall be not less than 90% of the specified minimum average thickness.
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>
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> In this case 100% insulation level is appropriate for 15kV conductors.
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[[nfpa-70_311_mv-conductors#311.10(B) Thickness of Insulation and Jacket for Nonshielded Insulated Conductors.]]
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| Voltage Rating | Insulation Level | Insulation Thickness |
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| --------------:| ----------------:| --------------------:|
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| 5kV | 100% | 90 mils |
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| 5kV | 133% | 115 mils |
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| 5kV | 173% | 140 mils |
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| 8kV | 100% | 115 mils |
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| 8kV | 133% | 140 mils |
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| 8kV | 173% | 175 mils |
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| 15kV | 100% | 175 mils |
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| 15kV | 133% | 220 mils |
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| 15kV | 173% | 260 mils |
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| 25kV | 100% | 260 mils |
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| 25kV | 133% | 320 mils |
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| 25kV | 173% | 420 mils |
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| 35kV | 100% | 345 mils |
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| 35kV | 133% | 420 mils |
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| 35kV | 173% | 580 mils |
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