76 lines
1.7 KiB
Markdown
76 lines
1.7 KiB
Markdown
---
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id:
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aliases: []
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tags:
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- occupational/takeoff
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- status/draft
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- type/guide
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title: Subfeeds
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dg-publish: true
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---
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# Subfeeds Takeoff
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Use adders appropriate for the difference in elevation.
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Use an additional 10ft for makeup when using cable.
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> [!tip]
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> Identify if and where typicals can be used
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## Multi-Circuit Homerun Subfeeds
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Typical of hotels and dormitories.
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Route from panel to center of the room.
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### Wiring Method Selection
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[[wiring-method-selection#Multi-Circuit Homeruns]]
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### Voltage Drop
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_If_ voltage drop is to be considered in takeoff,
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Use the table provided in the drawings.
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If no table is provided, use the following:
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| Wire Size | Max Length |
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| --------: | ---------: |
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| #12 | 100ft |
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| #10 | 200ft |
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| #8 | >200ft |
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## Unit Load Center Subfeeds
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Route from meter center to unit load center.
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#### Voltage Drop
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Larger of the listed demand current
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and 80% of the panel rating.
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#### Pigtail Adaptors
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[[distribution-equipment#Pigtail Adaptors|Pigtail Adaptors]]
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Use where conductors are oversized
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(for voltage drop or otherwise).
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| Load Center Size | Max Feeder Size |
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| ---------------- | --------------- |
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| 100A | 2/0 AWG |
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| 125A | 3/0 AWG |
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| 150A | 4/0 AWG |
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| 225A | 300 kcmil |
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| 400A | 500 kcmil |
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`ITEM DATABASE`/`WIRE & CABLE ACCESSORIES`/`WIRE LUGS & SPLICING`/`PIGTAIL ADAPTORS...`/`ADAPTOR STRAIGHT PIGTAIL - ...`
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#### Meter Center Troughs
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Only for PVC subfeeds where we own voltage drop.
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* `Area` = "Typical - Building Levels With Meter Centers"
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* `System` = "Electrical"
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* `Phase` = "Sub Feeders"
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`ITEM DATABASE`/`DISTRIBUTION`/`BUDGET ITEMS $ & LBR`/`METER CENTER WIRE TROUGH ($400/E)`
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