3.3 KiB
id, aliases, title, tags, up
| id | aliases | title | tags | up | ||||
|---|---|---|---|---|---|---|---|---|
|
Feeders Takeoff |
|
takeoff-scripts |
Feeders Takeoff
Important
Complete pre-takeoff-research, including conest-wiring-method-selection, before beginning takeoff.
Scope
- Primaries
- Secondaries
- Feeders
- Grounding
Formatting
All feeder takeoff descriptions should be prefixed with <parent> TO <child>
It is acceptable to use typicals for identical feeders
(i.e. meter centers fed from bus plugs)
so long as the typical is in Area = "01 - Feeders/Risers ...".1
Routing
Run parallel to building lines and route through corridors where possible.
Important
All takeoffs in Systems with names including "site" should be in "Site" Area, Phase, and Bid Item breakdowns.
For adjacent panels, use a minimum 10ft length.
Adders
Use the difference in elevation between equipment2 or 10ft, whichever is greater.
It is not necessary to change this logic for site runs.3 4
Primaries
[!info] Breakdowns
Area= "2 - Site"Phase= "Site"System= "PRI - Primaries"
Usually only empty conduit if included.
Secondaries
[!info] Breakdowns
Area= "2 - Site"Phase= "Site"System= "SEC - Secondaries"
Wiring on Vault Racks
Where secondary conductors run on racks in utility vaults manually set the length of conduit, measure the wire length, add 20ft in addition to previously mentioned adders.5
Feeders
[!info] Breakdowns
Area= "01 - Feeders/Risers Building"Phase= "Feeders"System= "FRR - Feeders and Risers"
[!info] Garage Feeders
Area"01 - Feeders/Risers Garage" is seldom used. It may be appropriate for totally separate parking garage buildings. Seek clarification before using.
Bus Duct
COMMON ASSEMBLIES/DISTRIBUTION/BUS DUCT/...
Delete unnecessary items and change Fct 1
to get the correct quantities for the use case.
Conductor Support
In lieu of more stringent requirements that may be imposed by project requirements, minimum support for vertical conductors is determined by nfpa-70_300_general-requirements#300.19(A) Spacing Intervals --- Maximum.
Various heuristics exist among ConEst teams.
Assuming minimum 40ft spacing
(the absolute minimum for feeders we're likely to encounter)
for all conductors is popular even among more detail-favoring seniors.
I generally prefer not to use a heuristic
because takeoff-calcs.xlsm trivializes accurate selection
and results in far fewer necessary supports.
Like #Sleeving, it is acceptable to takeoff total counts
ITEM DATABASE/CONDUIT & FITTINGS/CABLE SUPPORT / WEDGES/... COMPLETE FITTING/...
Grounding
See grounding-takeoff.
Sleeving
See sleeving-takeoff.
Because feeders are not broken down by level
(they use Area = "01 - Feeders/Risers ...")
it is acceptable to use total counts.
-
Not actually difference in elevation. A site run from the bottom to the top of a hill may still only need 10ft. This needs more precise wording. ↩︎
-
I will remove this line when I break the habit. ↩︎
-
art-baldwin at some point, I think. ↩︎