If you are laying out electronic components in a DIN rail system, chances are you will be adding some sort of terminal block.

This type oftain referred to as a barrier strip will suffice if you only need a couple connections on each terminal.

This one is rated at 600V and 45A.  I use these to bring AC power to my DIN rail systems.  This particular one is mounted on two of my short DIN rail brackets.

You can get them here:

45A Barrier Strip with Cover


DIN Rail Terminal Blocks

terminalblock kit.jpg

For the most part, this page will concentrate on the DIN Rail Terminal Blocks.

This is actually a terminal block kit.  It contains:

  • 5 Black 30A Terminal Blocks
  • 5 Red 30A Terminal Blocks
  • 2 Terminal Block End Brackets
  • 1 5" Aluminum DIN Rail

This is a great starter kit and is highly recommended.

You can get the kit here:

DIN Rail Terminal Block Kit

These pictures show the typical anatomy of an individual terminal block.  While the overall shape is the same the thickness will vary depending on the rated amperage.

5mm, 6mm, and 7mm are common thicknesses. The terminal block has two terminals on each side of the block.  They are joined together with a bar.


Different Brands

Here are two 6mm terminal blocks from different manufacturers, both rated at 30A.  Notice the shapes are slightly different.


Terminal Block End Covers

This is a particular brand that I have used.  They are inexpensive and have all the needed accessories.

You can purchase a set of ends to cover the open side once the terminal blocks have been mounted on your DIN rail.

You can get both the ASI Terminal blocks and covers here:

ASI 30A Terminal Blocks

ASA Terminal Block Cover


External Bridge

An external bridge is one way of joining several terminal blocks together.

They are cut to size then inserted into one side of the block. The terminals are then tightened against the bridge.

You can still insert a wire into the block with a bridge.  Loosen the terminal screw and slide the wire under the bridge, then tighten the terminal screw.  I do this all the time and it works great.

Just keep in mind that when you loosen the terminal screw the other side of the terminal block is no longer attached to the bus until you tighten the terminal screw.

You can get them here:

6mm External Bridges


Bridge Spacing

The external bridges shown here have a spacing of 6mm.

They fit perfectly into 6mm terminal blocks. When used with thinner blocks you will need to space the blocks apart slightly.

Notice the spacing on the thinner blue blocks.  This works out ok since the terminal block is tighten down on the bridge it keeps things pretty secure.

6mm External Bridges


Locking End Blocks

This is a locking end block. Not only do they cover the ends of the terminal blocks, they have screws that secure them to the DIN rail thus, securing the whole set of terminal blocks.  They can also be used as dividers.

DIN Rail Terminal Block Ends Stops


Bridge Shorts

Be real careful when ataching external bridges to the terminal blocks.  The cut ends of a cut bridge can short out if they touch.


Label Terminal Blocks

Its a good idea to label terminal blocks.  


Get Creative

Here I have used terminal blocks from one manufacture to divide block sets from another.


Some more Links


I have a few more terminal block parts on the way. I will add links as I test them out.