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@@ -13,7 +13,7 @@ title: Wiring Method Selection
Determine where each wiring method can be used.
NM/SER < PVC < MC < EMT-SS < EMT-Comp < IMC
## Example Wiring Method Selection
Below is an example Wiring Method Selection
for a [[ibc-construction-types#5-Over-1 Construction|podium]] construction.
@@ -43,7 +43,36 @@ I know PVC is preferable to MC in the case of feeders, subfeeds, and possibly ho
but I think they swap for branch.
-->
## Slab Thickness
## Standard Indoor Wiring Methods
NM/SER < PVC in Slab < MC < EMT-SS < EMT-Comp
### NM/SER Overhead
Nonmetallic-sheathed cables are combustible,
so not permissible in Non-Combustible (Type I, II) constructions.
See [[ibc-construction-types]] for more info.
#### Concealment
Cable type wiring methods (MC, NM, SE)
may only be used where they will be concealed from view.
### PVC in Slab
May require rigid stub-ups in certain cases,
which could make EMT more cost-effective.
Consult with the Senior Construction Estimator in this case.
#### Garage Slab
_Conventional Slab_: PVC in Slab
_Precast_: EMT
See [[pdi-breakdowns#Garage]] for more info.
#### Slab Thickness
Conduits may not be routed through slabs of thickness
less than 3 times the outer diameter of the conduit.
@@ -52,7 +81,7 @@ less than 3 times the outer diameter of the conduit.
| ------------:| ---------------------------:|
| 1/2" | 3.0 |
| 3/4" | 3.5 |
| 1" | 4.0 |
| 1" | 4.0 |
| 1-1/4" | 5.0 |
| 1-1/2" | 6.0 |
| 2" | 7.5 |
@@ -63,45 +92,51 @@ less than 3 times the outer diameter of the conduit.
| 5" | 17.0 |
| 6" | 20.0 |
## By Finish
#### Shear Walls
Cable type raceways (MC, NM, SE)
[[construction-methods#Shear Walls|Shear Walls]]
Shear walls, like those around stairwells and elevator shafts,
may be routed through with special permission.
#### Post-Tensioned Slabs
[[construction-methods#Post-Tensioned Slab|Post-Tensioned Slab]]
> [!cite] Joel Jansen 2025-08-15, in reference to Belle Meade Plaza (pp.)
> No affect on takeoff. Routing in slab still possible.
> [!cite] Joel Jansen 2025-08-21, in reference to Belle Meade Plaza (pp.)
> PT slabs do have some affect on takeoff.
> 3in conduit can not be run in an 11in PT slab.
#### Pan Deck Slabs
[[construction-methods#Pan Deck Slab|Pan Deck Slab]]
> [!cite] Joel Jansen 2025-08-15, in reference to Belle Meade Plaza (pp.)
> Do not route in slab.
### MC Cable Overhead
_Market Type = Assisted Living:_ MC-AP may be required.
#### Concealment
Cable type wiring methods (MC, NM, SE)
may only be used where they will be concealed from view.
Exception:
Temporary provisions for unfinished spaces (e.g. core and shell retail)
## By Construction Type
Nonmetallic-sheathed cables (NM/SER)
are not permissible in Non-Combustible (Type I, II) constructions.
See [[ibc-construction-types]] for more info.
## By Use-Case
### Multi-Circuit Homeruns
#### Multi-Circuit Homeruns
> [!quote] Art Baldwin (pp.)
> Multi-circuit MC is not cost-effective
> when considering the difficulty of rework.
> Use conduit, even EMT if necessary.
* Market Type = Assisted Living: MC-AP may be required.
## By Specification
> [!info] Example Specs Relevant to Wiring Methods Selection
> * 26XXXX - Raceway And Boxes For Electrical Systems
> * 26XXXX - Conduits For Electrical Systems
> * 26XXXX - Underground Ducts And Raceways For Electrical Systems
>
> * 26XXXX - Low-Voltage Electrical Power Conductors And Cables
>
> * 26XXXX - General Requirements For Electrical
> * 26XXXX - Common Work Results For Electrical
### Electrical Metallic Tubing (EMT)
### EMT Overhead
Set-screw fittings may not be acceptable.
@@ -121,21 +156,42 @@ Set-screw fittings may not be acceptable.
> > [!quote] Joel Jansen via Microsoft Teams @ 2025-10-15 09:33 AM
> > use set screw 🙂
### Rigid Polyvinyl Chloride Conduit (PVC)
## Standard Outdoor Wiring Methods
Not usually permissible exposed indoors in any construction,
except in Florida.
PVC Underground < EMT-Comp < IMC
May require rigid stub-ups in certain cases,
which could make EMT more cost-effective.
Consult with the Senior Construction Estimator in this case.
### PVC Underground
May require rigid stub-ups.
### EMT Overhead
Use compression fittings.
## Nonstandard Indoor Wiring Methods
### PVC Overhead
Not usually permissible, except in Florida.
## By Specification
> [!info] Example Specs Relevant to Wiring Methods Selection
> * 26XXXX - Raceway And Boxes For Electrical Systems
> * 26XXXX - Conduits For Electrical Systems
> * 26XXXX - Underground Ducts And Raceways For Electrical Systems
>
> * 26XXXX - Low-Voltage Electrical Power Conductors And Cables
>
> * 26XXXX - General Requirements For Electrical
> * 26XXXX - Common Work Results For Electrical
## Flow Chart
```mermaid
flowchart LR
A[Construction Type]
A -- I, II --> B[Can can be run in slab?]
A -- I, II --> B[Can be run in slab?]
B -- No --> D[Concealed?]
B -- Yes --> PVC
D -- No --> EMT
@@ -143,5 +199,15 @@ flowchart LR
A -- III, IV, V --> C[Concealed?]
C -- No --> PVC
C -- Yes --> NM/SER
```
```
#### Fire Rated Feeders
PDI estimating practice is to run all "emergency" feeds
(life-safety or just standby)
in a 2-hour rated assembly.
This usually requires no change to takeoff for high-rises
since electrical riser rooms are themselves fire-rated.
* RHW-2 insulated conductors in conduit -- "Lifeline Cable"
* 2-hour rated metal clad cable -- "Vitalink"