Electronic Products & Technology

Easy wiring of even the smallest cables with ferrules starting at 0.34 mm²


Electronics CEL

Terminal blocks with push-in connection technology offer high wiring convenience and contact quality

Modern installation concepts aim for economic efficiency and flexibility, and not only in times of crisis. Even in the age of bits and bytes, “classic” terminal block wiring continues to offer development potential. With “PIT” (push-in terminals), Phoenix Contact introduces a new generation of terminal blocks with push-in connection technology.

Spring connection systems are currently the trend; this technology has established itself in the market along with universal screw systems. But a spring is not always a spring. While the spring cage pulls the cable against the current bar, the compression spring presses the cable against the current-carrying component. At first glance, this doesn’t seem to be a serious difference – nevertheless, the compression spring offers major advantages in ease of use. The special spring contour enables direct and tool-free wiring of rigid and flexible cables that are pre-assembled with ferrules or ultrasonically compressed wire ends. When the cable is fed into the terminal point, the spring opens automatically. At least in theory.

For over 30 years, Phoenix Contact has used the advantages of compression springs, which have become a standard in PCB connection technology. PIT terminal blocks are also based on the compression spring principle, but they set new standards for ease of use and ergonomics.

Up to now, only rigid cables the size of the terminal’s nominal cross section had sufficient stiffness for tool-free and relatively practical wiring of comparable products. PIT terminal blocks, however, work with plugging forces reduced by approximately 50 percent (Fig. 1). With the new terminal principle, flexible cables with ferrules starting at 0.34 mm² can be connected directly to the terminal point without tools. PIT represents a true direct plug terminal, because for the first time ease of use is offered regardless of the cable type. The easy handling reduces wiring times and the ergonomic design prevents fatigue at work – two important factors in daily operations.


Figure 1

PIT – Push-in terminal blocks with plug forces reduced by 50 percent enable the direct tool-free insertion of cables starting at 0.34 mm².

Advantages Unlock new Fields of Application

The advantages of this direct plug technology open up new fields of application for the terminal, such as sensor wiring in mechanical and plant engineering. The advantages also have an effect here. Like the other connection technologies from Phoenix Contact, the PIT also enables a secure, gas-tight and vibration-resistant connection.

The cable is disconnected by pressing the integrated latch. The latch’s surface is designed so that it can be operated with any screwdriver – slot, Phillips or other “pointed” tools of various sizes. Even the pressure of a ballpoint pen is enough to disconnect a cable.

The signal-coloured latch enables clear identification of the PIT terminal point. The service area and wire feeds are clearly separated so that for each terminal point the user only finds a single position for the feeding the wire. Among the numerous connection technologies on the market, PIT rises above the rest because the technology is self explanatory in its application. This prevents wiring errors caused by wrong cable connections.

For Cables between 0.14 and 4 mm²

Fully-isolated operation is an advantage in terms of safety. Working under pressure contravenes both norms and accident prevention regulations, but it still occurs in real life. Measurement, testing and rewiring during ongoing operation can also happen. The PIT latch enables safe contact protection and its isolation material keeps the internal contact elements separate from the service tool. This prevents direct contact between tools and current-carrying parts.

PIT accommodates rigid or finely stranded cables from 0.14 to 4 mm². Finely stranded cables that have not been pre-assembled can be connected through the simple use of the latch. The generously designed cable feed trough prevents the cable from fanning out. An integrated spring stop protects the contact and reliably restricts the spring path.

The PIT’s design is compact and straight, and cables are connected on the front side. A double function shaft in the middle of the terminal enables the cross-connection of potentials with plug-in bridges or for testing purposes.

A System with Uniform Accessories

The PIT terminal blocks form a fundamental component of the "CLIPLINE complete" terminal block system (see sidebar). Like other series, such as screw, spring-cage, quick and bolt connections, PIT uses the same complete line of accessories, such as plug-in bridges, testing equipment and labelling. This significantly reduces the cost of part storage. The compatibility of these systems also extends to other overlapping areas. For example, 10, 16 and 35 mm² feeds can be done with screw or spring-cage connectors, and the distribution of potentials can be performed with push-in technology or a fast connection system.

Figure 2

PIT is a component of the “CLIPLINE complete” product line – all connection technologies are compatible with the same accessories.

The PIT product family includes the complete nominal cross-section range of 2.5 mm². In addition to standard feed-through terminal blocks, the product program includes multilevel terminal blocks, functional terminals and pluggable terminal blocks.

The PIT-Combi type pluggable terminal blocks also offer a high degree of flexibility. In modular machine designs, pluggable electrical solutions enjoy clear advantages in the commissioning, service and transportation of individual units. PIT-Combi base terminals and connectors allow for individual combinations, and the required pin count can be custom-tailored for the application and coded to prevent transposition. This is a clear advantage over conventional plug connectors with fixed pin counts. With its 24 A / 800 V rating, the PIT-Combi is suitable for signal and power wiring.

PIT plugs are the first of its kind to offer snap-on cable housings. The plastic housings for robust operation have integrated strain relief and flexible kink protection for different cable diameters. The protective housings are available in all pin counts from 2 to 15.


The PIT series terminal blocks set a new standard for push-in technology. The ease of use ensures short wiring times for all types of cables, and plugging forces reduced by 50 percent enable tool-free wiring of the smallest cables without fatigue. Integrated latches make handling and use unambiguous, universal and foolproof. The product range is designed to be seamlessly and completely compatible with the “Clipline complete” terminal block system. International approvals enable these devices to be used in all markets and industries.



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