---
id:
aliases:
  - das
tags:
  - occupational/systems/standalone-systems
---
# Distributed Antenna Systems (DAS)

## Info

### Emergency Responder Radio Communication Systems (ERRCS)

Relevant Standard: NFPA 1225

### Cellular Systems

Less common than ERRCS are "cellular DAS" systems

## Sequence

### 1. Estimate preparation

Complete [[fire-alarm]] preparation and takeoff.

### 2. Takeoff

#### FACR to Every Elev. Shaft

`COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`DAS ASSEMBLIES`/`FACR TO ELEV PIT = ...`

Match Fire Alarm takeoff Length and Count

#### FACR to Every Staircase

`COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`DAS ASSEMBLIES`/`FACR TO STAIRWELL = ...`

Match Fire Alarm takeoff Length and Count

#### Stairwell Riser Every 2 Floors

`COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`DAS ASSEMBLIES`/`STAIRWELL RISER EVERY 2 FLRS = 1 1/2" EMT (20') W/ 16X16X6 BOX`

Create a Stairwell typical on every other floor

#### FACR to Electric Room

`COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`DAS ASSEMBLIES`/`FACR TO 2HR-RATED RM = 2" PVC40`

Match Fire Alarm takeoff Length

#### Electric Room Riser to Every Floor

`COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`DAS ASSEMBLIES`/`2HR-RATED RM RISER TO EVERY FLR = 2" EMT (15') W/ 16X16X6 BOX`

Takeoff in every Electric Room

#### Top 2H Rated Room To Roof

`COMMON ASSEMBLIES`/`FIRE ALARM & DAS SYSTEMS`/`DAS ASSEMBLIES`/`TOP 2HR RATED RM TO ROOF = 2" EMT W/ RMC WEATHERHEAD & IMC STUB`

Use 15' or Height of ceiling on last building level

#### Horizontal

CORRIDORS EMT OH = 1 1/2" EMT W/ 16X16X6 BOX EVERY 80'
CA.28.31.23

CORRIDORS DECK = 1 1/2" PVC40, STUBBY, FLEX W/ 16X16X6 BOX EVERY 80'
CA.28.31.21

1-1/2 through corridors w/ 16x16x6 J-Box

Length for every corridor/garage

### 3. Extension (Review and Checking)
