Collingwood JB5 (Parallel) Gel Filled Waterproof Junction Box

A Junction Box Built To Live Underground

The JB5 is a gel filled junction box for wiring Collingwood's parallel connected outdoor lighting, things like ground lights, bollards and wall lights fed from the same circuit. Instead of taping up a joint and hoping it holds, you get one small connector that seals the wiring inside a solid gel fill, built to stay watertight buried in soil or sat in a damp border.

The Parallel Version

This is the parallel configuration, meaning a single terminal block takes one incoming cable and splits it out to between one and three outputs. That suits a run of garden lights fed from a single circuit, where you need to branch off to each fitting rather than wiring them one after another. Clip latches at each end open to give access to the screw terminals, then close again once the gel fill goes in around the connection.

How It Works

Cables are clamped into the terminal block and the connector is then closed and filled with gel, which sets around the wiring and keeps water out of the joint. That gel fill combined with the closed housing gives the JB5 an IP68 rating, tested to withstand submersion to a depth of 1.3 metres. It's rated to a maximum of 250V AC and 16A, with a maximum conductor size of 1.5mm² and a cable diameter of 6.5 to 12mm. Collingwood's own WCR 375 black, 3 core rubber cable is the cable it's designed to be used with.

Where It Works Best

Use the JB5 anywhere an outdoor lighting cable needs to be joined or split below ground or somewhere damp, a border full of spike or ground lights, a run of lights along a path, or a junction hidden under decking or gravel. It's a sensible choice for gardens that get added to over time, where a new fitting needs tapping into an existing parallel run rather than a whole new cable back to the switch.

Built By A Specialist In Sealed LED Systems

Collingwood has focused on LED technology since 2002, designing and manufacturing from its base in Sywell, Northamptonshire. The brand says it was among the first to bring fully sealed, waterproof for life LED products to the UK electrical wholesale market, and a gel filled connector like the JB5 is a plain expression of that idea, keeping water out of a joint for good rather than relying on tape or a cap. Collingwood has also been awarded a Gold medal by EcoVadis, placing it in the top 5% of companies assessed globally for sustainability.

Good To Know

• IP68 rated, tested for submersion to 1.3 metres once sealed with gel
• Rated to a maximum of 250V AC and 16A
• Maximum conductor size of 1.5mm², cable diameter of 6.5 to 12mm
• Parallel wiring: one input splitting to one, two or three outputs
• Designed for use with Collingwood's WCR 375 black, 3 core rubber cable
• Covered by a 1 year warranty
• Moonlight Design recommends installation by a registered NICEIC electrician

Questions People Ask

• How many outputs can the JB5 take from one input? It splits a single incoming cable to between one and three outputs from its terminal block.
• Is the JB5 safe to bury in the ground? Yes, its gel fill and closed housing give it an IP68 rating, tested for submersion to 1.3 metres.
• What cable should I use with the JB5? Collingwood pairs it with WCR 375 black, 3 core rubber cable.
• What's the maximum load the JB5 can carry? It's rated to a maximum of 250V AC and 16A, with a maximum conductor size of 1.5mm².
• What's the difference between the JB5 and JB4? The JB5 is a parallel wired connector rated to 250V AC and 16A, while the JB4 is a series wired connector for lower voltage runs.

93.5mm length x 36mm width

• Collingwood Residential Accessories Guide 2025

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