All advantages at a glance SDKF …

Clamping range: 0.2 mm² – 2.5 mm² for solid, rigid stranded and flexible wires.
A number of wire cross sections can be combined in one terminal.
High pull-out forces.
Connection of rigid wires without activating the release lever.
Viewing window for visual inspection of the clamping points means greater safety during Installation.

DIN rail is based on a concept so
elegant that its growth is expanding
more than a century after it was
conceived: DIN rail terminal blocks
housing electrical and electronic
modules represent a $26 billion global
market that is expected to grow by up
to 6% annually in the next few years.
Although DIN rail enclosures play a
significant role in DIN rail, they rarely
gain the attention they should, so this
article will help remedy this situation.
DIN rail was born in Germany in the
1920s driven by the increasing number
of electrical connections required as
industrial electrification became more
complex. At the time, these
connections were made on bare
control panels that relied on whatever
terminals were handy, even nuts and
bolts, and some form of insulator. Not
only were these panels difficult to
construct, but they were also equally hard to maintain, unreliable and unsafe. The biggest
problem was that the more connections there were, the larger the panel had to be. Clearly, a
new approach was needed that allowed more connections to be placed closer together to save
space.
The solution was a small porcelain tray with an integrated metal bus bar that connected the
wires through screw terminals. To increase connection density without compromising safety,
the terminal blocks were packed into long strips with one side enclosed by the porcelain to
reduce the possibility of electrical shorts.

DIN rail was an instant success throughout Europe, and although it took
some time to displace rack panels in the U.S., it is now ubiquitous. A variety of variants have
also been created over the years to meet the needs of specific applications, as well as widths of
32 mm and 15 mm, but the symmetrical 35 mm wide top hat DIN rail has become the most
commonly used and accommodates a wide range of industrial control products and
components.

DIN rail components like terminal blocks and circuit breakers mount directly to the DIN rail via
mounting feet or latches (Figure 2). What DIN rail did not initially provide was a protective case
around electrical devices and later electronic components, so the DIN rail enclosure was
devised. PC boards installed in DIN rail mount enclosures are kept in place by PC board guides
or screw mounted to standoffs. The enclosures facilitate wiring by providing integrated
terminals on the outside of the enclosure that connect to the internal PC board via wire jumper,
card edge connections or machine solderable pins. Almost any PC board can be put on a DIN
rail and as these enclosures are generally designed to be used indoors water protection is
unnecessary with IP 20 or IP 40 rating typical for finger protection.

From a board manufacturer’s perspective, the goal is to reduce or eliminate the need for
enclosure customization purely to support a PC board of a specific size. F

Summary
The DIN rail has been a success since it first entered the market 100 years ago, and it is likely to
remain that way until something better comes along, which seems unlikely. Industrial control
panels are constantly evolving with more and more electronic devices being included in the
panel. The DIN rail enclosure has also evolved and there are now as many enclosure models
available as user scenarios, and the list continues to grow as Industry 4.0 starts to become a
reality, bringing with it even more types of board-level products and other devices that must be
securely housed while easily upgraded to add new features. With DIN rail it is simply a matter
of snapping them off and on.

WAGO’s 2601 series super-compact, tool-free PCB terminal blocks with lever technology allow quick and easy wiring of cross-sections from 26 AWG to 14 AWG.

These solid conductors and fine-stranded conductors with ferrules feature WAGO’s push-in CAGE CLAMP® connection technology that connects by simply pushing them into the unit. Terminating fine-stranded conductors and disconnecting any conductor type is quick and easy with the lever connection.

The tool-free wiring is intuitive for worldwide use, and the lever technology ensures that the contact point is always secure. The 2601 series PCB terminal block can be connected both vertically and horizontally to the PCB with a pin spacing of just 3.5 mm, taking up very little space on the board.

Beware the Wago lookalikes!

A review and demo of the WAGO 222 connectors. I show how to use the Wago 222 to create a lighting circuit, to connect and extend cables, and how to use them with the WAGOBOX Junction Box. I give a quick product overview with my thoughts on the Wago 222 series of connector blocks.