## **Emergency Lighting – UK Overview**

Emergency lighting is a crucial life safety system designed to provide illumination during power failures. In the UK, it's governed primarily by **BS 5266-1:2016**, which outlines design, installation, and maintenance standards for emergency lighting systems in non-domestic premises.

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### **Purpose of Emergency Lighting**

- Ensure occupants can safely evacuate a building during a power failure.
- Illuminate escape routes, signage, and high-risk task areas.
- Support firefighting operations if needed.

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### **Main Types of Emergency Lighting Systems**

#### 1. **Self-Contained (Stand-Alone) Systems**

**How it works:**  
Each luminaire contains its own battery and control gear. When the mains power fails, the battery takes over and provides illumination.

**Pros:**
- Simple to install and expand.
- No central battery or control system required.
- Lower initial cost.

**Cons:**
- Batteries must be maintained/replaced individually.
- Not ideal for large or complex buildings.
- Testing and maintenance can be time-consuming without automation.

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#### 2. **Central Battery Systems**

**How it works:**  
A central battery (or bank of batteries) supplies power to all emergency luminaires through a dedicated circuit during power failures.

**Pros:**
- Easier centralized maintenance.
- Longer battery lifespan (typically 5–10 years).
- High performance and reliability for large buildings.

**Cons:**
- Higher upfront cost and installation complexity.
- Requires space for battery housing and cabling infrastructure.
- Full system failure if the central battery fails (unless redundant systems are used).

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#### 3. **Sustained (Combined) Luminaires**

**How it works:**  
Combines a standard light source with a separate emergency light source (usually a battery-powered LED). It operates on mains under normal conditions and switches to battery power during failure.

**Pros:**
- Functions both as normal and emergency lighting.
- Good for areas where constant illumination is needed.

**Cons:**
- Can be bulkier.
- Slightly more complex than self-contained-only fittings.

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#### 4. **Maintained vs Non-Maintained Luminaires**

- **Maintained:** Always on; uses mains power normally, switches to battery in a power cut.
  - *Best for*: Public areas like cinemas, theatres, etc.
- **Non-Maintained:** Only illuminates during power failure.
  - *Best for*: Staff-only or well-lit areas during normal use.

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### **Emergency Lighting Categories (BS 5266)**

- **Escape Route Lighting:** For corridors, stairways, and exit routes.
- **Open Area (Anti-Panic) Lighting:** Prevents panic and helps occupants reach escape routes.
- **High-Risk Task Area Lighting:** Illuminates dangerous processes for safe shutdown.

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### **Maintenance & Testing (Basic Overview)**

Emergency lighting systems must be tested regularly to comply with BS 5266-1:2016 and ensure they function correctly in an emergency. The requirements differ slightly depending on the type of system.

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#### **General Testing (All Systems)**

| **Test Type**       | **Frequency**         | **Details** |
|---------------------|-----------------------|-------------|
| **Monthly Functional Test** | Every month | Brief test (typically a few minutes) to ensure lights illuminate on power failure. |
| **Annual Full Duration Test** | Every 12 months | Luminaires must operate for their full rated duration (usually 1 or 3 hours). |
| **Visual Inspections** | Ongoing | Check for physical damage, obstructions, or signs of wear. |

Automated testing systems are often used to log and report test results, especially in large or complex buildings.

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### **Central Battery System Maintenance**

Central battery systems require more specialist upkeep due to their size and critical function. Key elements include:

#### **Battery Replacement Periods**

| **Battery Type**         | **Typical Lifespan** |
|--------------------------|----------------------|
| **Vented Lead-Acid**     | 5–10 years           |
| **Sealed Lead-Acid (VRLA)** | 5–7 years           |
| **Nickel-Cadmium (NiCd)**| 7–10 years           |
| **Lithium-based (where used)** | Up to 10+ years (check manufacturer guidance) |

> 🔧 **Best Practice**: Batteries should be replaced **proactively**, based on performance metrics and manufacturer guidance — not just failure.

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#### **Additional Testing Requirements for Central Battery Systems**

- **Daily Visual Check** (for non-automated systems):
  - Indicators and meters on the central battery unit should be checked by a responsible person.
- **Quarterly Inspection**:
  - Check all connections, ventilation, battery voltage levels, and cleanliness.
- **Annual Load Test**:
  - Simulate a full power failure and ensure the battery sustains emergency lighting for the rated duration (usually 1 or 3 hours).

> 🧯 Fire safety records should include logbooks of all inspections, test results, and maintenance actions.
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