---
id: feeders
aliases: []
tags:
  - occupational/systems/feeders
---
# Feeders

## Info

### Routing and Structural Considerations

#### Shear Walls

Shear walls, like those around stairwells and elevator shafts,
may be routed through with special permission.

#### Post-Tensioned Slabs

> [!example]
> STRUCTURAL SLAB IS AN 8-INCH THICK
> UNBONDED POST-TENSIONED TWO-WAY SLAB UNLESS NOTED OTHERWISE.

> [!cite] Joel Jansen 2025-08-15, in reference to Belle Meade Plaza, pp.
> No affect on takeoff. Routing in slab still possible.

#### Pan Deck Slabs

> [!example]
> STRUCTURAL SLAB IS 3 1/2 INCHES OF NORMALWEIGHT CONCRETE
> ON 3-INCH COMPOSITE STEEL DECK UNLESS NOTED OTHERWISE.

> [!cite] Joel Jansen 2025-08-15, in reference to Belle Meade Plaza, pp.
> Do not route in slab.

### Formatting

All feeder takeoff descriptions should be prefixed with `<parent> TO <child>`

> [!cite] Joel Jansen, in reference to Omni Hotels Raleigh, pp.
> It is acceptable to use typicals for identical feeders
> so long as the typical is in the Feeders `Area`

## Sequence

### 1. Estimate preparation

Read about the project specifications and construction type:
* Delivery Method (Plans & Specs, Design Build, Design Assist, Preliminary Budget)
* Deck thickness
* Wiring method
* Conductor material (Aluminum/Copper)

Locate:
* Riser Diagram
* Feeder Schedule (if present)
* Main Electrical rooms and panel locations
* Routing (if present)

### 2. Takeoff

* Choose a starting point on the riser
* Determine wire & Conduit makeup (3Ph/1Ph, AL/CU, Conduit)
* Measure off the length of the feed _ADDERS_
    * Square corners, use corridors if possible

> [!important]
> All takeoffs in Systems with names including "site"
> should be in "Site" Area, Phase, and Bid Item breakdowns.

#### Adders

Use the difference in elevation between equipment
or 10ft, whichever is greater.

Add an additional 5ft for site runs
(primaries, secondaries, etc.).

#### Primaries

Empty conduit.

#### Secondaries

> [!info] Vaults and Secondary Connections
> In utility vaults, secondary conductors sometimes run on racks,
> far past their entrance conduits, to their transformers.
> It is necessary to add this distance to the wire makeup,
> rather than simply measure the conduit assembly to the transformer.

#### Feeders

#### Bus Duct

`COMMON ASSEMBLIES`/`DISTRIBUTION`/`BUS DUCT`

#### Cable Support

> [!quote] 300.19 Supporting Conductors in Vertical Raceways.
> **(A) Spacing Intervals -- Maximum.**
> Conductors in vertical raceways shall be supported
> if the vertical rise exceeds the values in Table 300.19(A).
> At least one support method shall be provided for each conductor
> at the top of the vertical raceway or as close to the top as practical.
> Intermediate supports shall be provided
> as necessary to limit supported conductor lengths
> to not greater than those values specified in Table 300.19(A).

> [!cite] Table 300.19(A) Spacings for Conductor Supports
>
> | Conductor Size                   | Aluminum or Copper-Clad Aluminum | Copper |
> | -------------------------------- | --------------------------------:| ------:|
> | 18 AWG through 8 AWG             |                            100ft |  100ft |
> | 6 AWG through 1/0 AWG            |                            200ft |  100ft |
> | 2/0 AWG through 4/0 AWG          |                            180ft |   80ft |
> | Over 4/0 AWG through 350 kcmil   |                            135ft |   60ft |
> | Over 350 kcmil through 500 kcmil |                            120ft |   50ft |
> | Over 500 kcmil through 750 kcmil |                             95ft |   40ft |
> | Over 750 kcmil                   |                             85ft |   35ft |

`ITEM DATABASE`/`CONDUIT & FITTINGS`/`CABLE SUPPORT / WEDGES`/`... COMPLETE FITTING`/...

#### Grounding

See [[grounding]].

#### Sleeving

See [[sleeving]].

### 3. Extension (Review and Checking)