zmVault/subfeeds.md

id, aliases, tags

id	aliases	tags
		occupational/systems/subfeeds

Subfeeds

Sequence

1. Estimate preparation

1. Read about the project specifications and construction type

• Delivery Method: (Plans & Specs, Design Build, Design Assist, Preliminary Budget)
• Deck Thickness
• Corridor Ceiling type

2. In the drawings, locate:

• Unit Panel Schedules
• Unit Load Calculations
• Riser Diagram
• Subfeed schedule (if present)

2. Takeoff

1. Determine wiring method

   Construction Type	Wiring Method	Subfeed Options
   1,2	MC Cable	MC, PVC, EMT
   3,4,5	NM Cable	SER, EMT

   %% TODO: Create flow chart for wiring methods. Some cases to mention:

   • Deck thickness (minimum 3x conduit outer diameter)
   • Renovations (may not be able to run in slab) %%

2. Route subfeeds to the Meter Centers using appropriate adder lengths Add an additional 10ft for makeup when using MC cable.

   Tip

   Identify if and where typicals can be used

3. Assign material to lengths and apply Voltage drop if applicable

4. Pigtail Adaptors and Wireway Troughs if applicable

Pigtail Adaptors

!

Pigtail adaptors are used where feeder wires exceed the range of panel lugs.

Load Center Size	Max Feeder Size
100A	2/0 AWG
125A	3/0 AWG
150A	4/0 AWG
225A	300 kcmil
400A	500 kcmil

ITEM DATABASE/WIRE & CABLE ACCESSORIES/WIRE LUGS & SPLICING/PIGTAIL ADAPTORS.../ADAPTOR STRAIGHT PIGTAIL - ...

[!info] "Pigtail adaptor" is the most common name and spelling for the device, however it's something of a misnomer, having nothing to do with pigtails (a short length of wire), the name likely stemming from the device being used in lieu of a pigtail.

Meter Center Troughs

Only for PVC subfeeds where we own voltage drop.

• Area = "Typical - Building Levels With Meter Centers"
• System = "Electrical"
• Phase = "Sub Feeders"

ITEM DATABASE/DISTRIBUTION/BUDGET ITEMS $ & LBR/METER CENTER WIRE TROUGH ($400/E)

3. Extension (Review and Checking)

1. Use the extension tab to determine the Correct Quantity