Wago 221 Junction Box for flex wire 3 core, 4 core or 5 core [compact] [snap fit]

Please see currently updated version of this model:

Compact 2x M3 screws

This model will no longer receive updates.

-----------

Electrical safety warning:

Messing with electrics is dangerous and kills. Please don't attempt to use this junction box if you are not familiar with electric safety procedures and regulations in force in your country. Your safety is not my responsibility.

Description:

I needed a junction box for a 4-core flex wire and instead of going to the shop and buying one, I decided to spend a few tens of hours and a chunk of filament in prototyping to design and build my own. If you are lurking this site, you'll understand.

This is the third variation of this junction box. I designed the standard with fittings for thermal threaded inserts and 4x M3 bolts, then a compact with only 2 bolts, and now one that snap fits and has no bolts.

This is the compact snap fit version.

If you would like to view the other variations, please see below:

• Compact 2x M3 screws
• Compact model for 3 wires and Wago 212-413
• In line enclosure for Wago 212-2411

The snap fit version has a lid that clips into the box with 2 snap fit tabs either side. Like the compact version, the lid is reinforced to reduce the chance of warping or lifting at the ends.

• Holds regular wago 221 2-way connectors (221-412: https://www.wago.com/gb/installation-terminal-blocks-and-connectors/splicing-connector-with-levers/p/221-412). The connectors support single core and multi-strand wire, so technically there is no need to add bootlace ferrules. Personally I prefer to have them but I understand there's pros and cons to having them. Your call.
• Models available for 3, 4 or 5 core 1mm2 flex wires (318*Y) with corresponding wire hole sizes. Other types of wires (different conductor section or insulation) will require adjustment to the wire entry holes
• Variations available for bottom or side wire entry (bottom-side, bottom-bottom, side-side)
• The enclosure was designed for multi-strand flexible copper wires. It probably won't work for rigid single core wires due to space and routing, and the wire entry hole is not suitable for twin&earth. The latter is easy to fix. The former requires some experimentation.
• The lid attaches to the box using 2 snap fits. They were designed for a very solid fit for infrequent operation, as a junction box is meant to be installed and left alone for long periods of time, usually.

Measurements

• Junction box compact snap fit 3x core: 34.48W x 52.16L x 19.31H (mm)
• Junction box compact snap fit 4x core: 44.14W x 52.16L x 19.31H (mm)
• Junction box compact snap fit 5x core: 53.8W x 52.16L x 19.31H (mm)

Whichever sides have wire entry holes take another 1mm for the round lip, so width and length will vary up to 1mm depending on the variation selected.

Additional design features

• Snug cable entry hole to limit dust ingress
• Slot for cable ties on the inside for cable relief
• Snap fit lid
• Corner radius for cable tie to loop around easily
• Wago connectors are ‘locked in place’ so they don't move once the lid is placed