Electrical Junction Boxes for Safe Connections
Electrical junction boxes are enclosures that house and protect cable connections, keeping terminations safe from damage, dust and moisture while leaving them accessible for inspection. Our range covers round and square PVC boxes, IP56 weatherproof enclosures, Wiska IP55 boxes and Hensel cable junction boxes for 4mm² and 6mm² conductors.
You will also find Knightsbridge 20A and Selectric 30A terminal boxes, Termination Technology lighting connection boxes and Live Electrical 100A terminal blocks. Trade customers get trade prices, and in-stock boxes ordered before 5pm arrive next working day anywhere in NI or ROI.
How to choose the right junction box
A junction box needs to suit the cable size, the current it will carry, the environment and whether the connections must stay accessible. Use the points below to narrow down the options.
Types of junction box
- Terminal junction boxes such as the Knightsbridge 20A and Selectric 30A versions have fixed terminals, ideal for lighting and radial circuits in lofts and ceiling voids.
- Adaptable and weatherproof enclosures rated IP55 or IP56 suit outdoor, damp and dusty locations, and can be fitted with glands or grommets.
- Round junction boxes with grommets are a common choice for conduit work and lighting points.
- Cable junction boxes from Hensel are sized by conductor, for example 4mm² or 6mm², for clean distribution in commercial work.
Key specifications to check
Match the terminal rating to the circuit protective device and the conductor size to the terminal capacity. Check the IP rating against the location: IP44 protects against splashes, while IP55 and IP56 offer greater protection from dust and water jets. Consider internal volume too, as overcrowded boxes make terminations harder and can lead to heat build-up. Where larger conductors need distributing, high-current terminal blocks rated to 100A and 35mm² give a neat solution.
Installation and compliance
Connections in junction boxes generally need to remain accessible for inspection unless a maintenance-free method is used, so check current wiring regulations (BS 7671) before boxing in a joint. Use the correct cable glands or grommets to keep the IP rating intact, and secure cables so terminals are not under strain. For connections inside a box, lever and pushwire connectors are a quick option. For larger or outdoor applications, see our galvanised and PVC enclosures.
Why order from Meteor
We are a family-run electrical wholesaler with more than 5,000 products in stock and over 100 trade brands. Free delivery applies over £30 / €35 ex VAT, credit accounts are available subject to approval, and our team answers on 028 8675 1515 (048 from ROI), Monday to Friday, 8am to 5pm.
FAQ's
- What size junction box do I need for a lighting circuit?
- Can a junction box be buried in a wall or under floorboards?
- What IP rating does an outdoor junction box need?
- Are metal or plastic junction boxes better?
- What are high-current terminal blocks used for?
- Can I collect junction boxes from a trade counter?