Home A - Z
Page Index

Commit 0882a7

2025-09-19 19:27:31 R. Bishop: -/-
pava.md ..
@@ 1,4 1,4 @@
- # 🔊 Public Address & Voice Alarm (PAVA) Systems
+ # Public Address & Voice Alarm (PAVA) Systems
## Overview
@@ 10,7 10,7 @@
## Regulatory Framework
- ### ⚖Electricity at Work Regulations 1989 (EAWR)
+ ### Electricity at Work Regulations 1989 (EAWR)
* All electrical systems must be constructed and maintained so as to **prevent danger**.
* Applies to **PAVA systems** because:
@@ 23,7 23,7 @@
## Standards and Compliance
- ### 🏗Design & Installation
+ ### Design & Installation
* **BS 5839-8** - Code of practice for voice alarm systems.
* **BS EN 54-16** - Voice alarm control and indicating equipment.
@@ 40,7 40,7 @@
* **BS 8519** - Selection/installation of fire-resistant cable systems for life safety and firefighting systems.
* **Enhanced fire-resisting cables** generally required in stadiums, hospitals, tunnels, transport hubs.
- ### 🔊 Operational Requirements
+ ### Operational Requirements
* PAVA must always have **priority** over background music, advertising, or commentary.
* Messages must be **intelligible** (tested via STIPA/STI).
@@ 50,19 50,19 @@
## Electrical Safety Considerations
- ### 🔹 100 V Line Circuits
+ ### 100 V Line Circuits
* Operate at **70-100 V RMS AC audio signal** → **Band II (LV)** under **BS 7671**.
* Requires electrical competence for installation and testing (continuity, insulation resistance, polarity).
* Must be segregated from Band I circuits (fire alarm loops, ELV data/control).
- ### 🔹 High-Voltage Internal Components
+ ### High-Voltage Internal Components
* Amplifiers, PSU units, and changeover modules can operate with **300-600 V DC rails** internally.
* Only competent persons should access live enclosures.
* Risk assessments under EAWR required before live testing/maintenance.
- ### 🔹 Surge & Lightning Protection
+ ### Surge & Lightning Protection
* Long 100 V lines between buildings or across stadium/transport sites are susceptible to induced surges.
* Must be protected via SPDs as per **BS 7671:534** and **BS EN 62305-4**.
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9