Site Distribution Boxes

About Site Distribution Boxes

Site distribution boxes are essential pieces of electrical equipment designed to safely split a single power source into multiple outlets on construction sites, workshops, and industrial environments. These robust units allow tradespeople to run several power tools and equipment simultaneously from one supply, eliminating the need for dangerous daisy-chaining of extension leads. Built to withstand the rigours of professional site work, distribution boxes feature durable steel or heavy-duty plastic enclosures with carry handles for easy relocation around busy work areas.

The range at Tooled-Up.com includes both 110v and 240v distribution units, with configurations typically offering between 4 and 6 outlet sockets. Most units are rated to IP44 standard or higher, providing protection against dust and water ingress – crucial features for outdoor and dusty environments. Quality brands such as Defender, Sealey, and Faithfull manufacture these units to comply with BS EN 60309 standards, ensuring they meet UK electrical safety regulations. Each distribution box is supplied with an integrated power cable and industrial plug, ready for immediate use on site.

Modern site distribution boxes incorporate thermal overload protection and individual socket covers to prevent accidental disconnection and protect against the elements when outlets aren't in use. The stable base design ensures units remain upright even on uneven ground, whilst the compact footprint means they won't obstruct busy walkways or working areas.

Jargon Buster

• 110v Centre-Tapped System: The standard voltage for portable tools on UK construction sites, providing 55v to earth for enhanced safety. If a cable is cut or damaged, the reduced voltage significantly lowers the risk of serious electric shock compared to 240v mains power.
• IP44 Rating: An Ingress Protection rating indicating the unit is protected against solid objects larger than 1mm and water splashes from any direction. Essential for site distribution boxes used in outdoor or dusty environments.
• 16A Socket: A 16 amp rated outlet designed to handle tools and equipment drawing up to 16 amps of current. Standard for most professional power tool applications on construction sites.
• BS EN 60309: The British and European standard governing industrial plugs, sockets, and couplers. Compliance ensures electrical equipment meets stringent safety and performance requirements.
• Thermal Overload Protection: An automatic cut-off system that disconnects power if the unit becomes overheated due to excessive load or poor ventilation, preventing damage and fire hazards.
• Spider Box: A colloquial term for distribution units with radial or star-shaped socket arrangements, allowing connection points to face different directions for easier cable management.

Who Uses Site Distribution Boxes?

• Electricians and electrical contractors installing and maintaining electrical systems on construction sites
• General builders and construction workers requiring multiple power points for various tools and equipment
• Carpenters and joiners running saws, routers, sanders, and other woodworking machinery simultaneously
• Plasterers and decorators powering mixers, lights, and extraction equipment
• Groundworkers and civil engineers operating power tools in outdoor environments
• Maintenance engineers in industrial facilities and commercial premises
• Event contractors and exhibition installers requiring temporary power distribution solutions
• Facilities managers maintaining commercial and institutional buildings
• DIY enthusiasts and home renovators tackling substantial projects requiring multiple power tools

How to Choose the Right Site Distribution Boxes

Voltage Requirements: Determine whether you need 110v or 240v distribution. Construction sites typically mandate 110v equipment for portable tools due to HSE safety recommendations, whilst 240v units suit workshop environments and less hazardous applications. Some Tooled-Up customers maintain both types for different working scenarios.

Number of Outlets: Consider how many tools or equipment items you'll run simultaneously. Four-way units suffice for small teams or limited applications, whilst six-way boxes better suit larger crews or equipment-intensive tasks. Remember that exceeding the total load capacity is dangerous regardless of available sockets.

Build Quality and Protection Rating: Look for robust steel construction with IP44 rating minimum for site work. Units exposed to particularly harsh conditions benefit from higher IP ratings. Check for features like reinforced corners, stable bases, and protective socket covers.

Cable Length and Plug Type: Most distribution boxes include a 3-5 metre integrated cable with appropriate industrial plug. Consider whether this reach suits your typical working distances from transformers or power sources. Longer cables offer flexibility but create trip hazards.

Safety Features: Prioritise units with thermal overload protection and RCD compatibility. Ensure compliance with current BS EN standards. Quality brands like Defender incorporate multiple safety features as standard.

Portability: Carry handles and compact dimensions matter when relocating equipment frequently around sites. Check the unit weight – heavier steel construction offers durability but may prove cumbersome for solo workers.

Popular Accessories

• Site transformers (110v step-down units) to convert 240v mains power to safe 110v site voltage
• Industrial extension leads in various lengths with 16A connectors for reaching distant work areas
• Cable reels for organised cable management and storage between jobs
• RCD adapters providing additional earth leakage protection for enhanced electrical safety
• Replacement plugs and sockets for maintenance and repair of distribution equipment
• Portable site lights and work lamps to illuminate working areas
• Cable protectors and ramps to prevent trip hazards and protect cables from vehicle damage
• Weatherproof covers for additional protection in extreme outdoor conditions

Safety Information

Never exceed the maximum current rating of the distribution box – typically 16A per socket with an overall unit limit. Calculate the combined current draw of all connected equipment before plugging in. Overloading causes overheating, potential fire, and damaged tools.

Always conduct visual inspections before use. Check for cracked casings, damaged cables, loose connections, or missing socket covers. Remove damaged units from service immediately and arrange professional repair or replacement.

Position distribution boxes on stable, level ground away from standing water, even when rated IP44 or higher. Ensure adequate ventilation around the unit and never cover air vents. Keep cables tidy to prevent trip hazards, and never run cables through doorways where they may be crushed or create access issues.

Use only appropriately rated equipment with your distribution box. The 110v site system is specifically designed for safety on construction sites – never attempt to use 240v tools with 110v distribution or vice versa without proper transformers. Follow HSE guidelines regarding portable electrical equipment on construction sites, and ensure all users understand basic electrical safety principles.

Frequently Asked Questions

What's the difference between 110v and 240v distribution boxes?
110v distribution boxes are designed for construction site use where HSE guidance recommends centre-tapped 110v systems for portable tools, providing only 55v to earth for enhanced shock protection. 240v units are standard mains voltage, typically used in workshops, garages, and less hazardous environments. Most construction sites mandate 110v equipment for safety compliance.

Can I plug a 13A tool into a 16A distribution box socket?
No – distribution boxes use industrial 16A sockets (BS EN 60309 standard) with different pin configurations to standard 13A domestic plugs. Your tools need 16A industrial plugs to connect, or you'll need appropriate adapters, though these aren't generally recommended for site work.

How many power tools can I run from a 4-way distribution box?
This depends on the current draw of each tool, not just the number of sockets available. Check each tool's amperage rating (usually on the specification label) and ensure the total doesn't exceed the distribution box capacity – typically 16A overall for most units. Running four low-draw tools simultaneously may be fine, but two high-powered tools could overload the system.

Do distribution boxes need PAT testing?
Yes, site distribution boxes are portable electrical equipment requiring periodic inspection and testing under the Electricity at Work Regulations 1989. Construction equipment typically requires testing every three months, whilst lower-risk environments may test annually. Keep records of all tests and clearly label units with their next test date.

What does IP44 rating mean for site distribution boxes?
IP44 means the unit is protected against solid objects larger than 1mm (including most dust) and water splashes from any direction. This makes IP44-rated boxes suitable for outdoor use and dusty construction environments, though they shouldn't be submerged or exposed to high-pressure water jets. Higher ratings (IP54, IP65) offer increased protection for particularly harsh conditions.