Universal genius of M12 connectors

Size M12 connectors are used in many areas – today they are the standard when it comes to connection systems for plants and machines. With the new power connectors from the “M12 Power” series, the application areas have now been expanded to include the power domain (Figure 1).

In recent years, control technology has advanced at a rapid pace. The requirements on the control components, but also on the connection systems, have changed significantly. Devices are becoming more compact and at the same time the electrical interfaces are expected to fulfill more functions. This trend is also having an impact on M12 connection systems. Originally having just 4 positions, connectors for new applications in sensor systems are being successively expanded up to 17 positions. M12 connectors have been upgraded to be capable of data transfer rates up to 10 Gbit/s, which means that they can also be used in Ethernet-based environments.

Reasons to use M12


Figure 1: M12 connectors can now also be used for power applications.

With these innovations, M12 connectors have made the transition from being pure sensor connectors to becoming today's leading universal connection system for sensors and actuators as well as for fieldbus and network technology. The wide acceptance of M12 connectors comes also as a result of international standardisation. New pin assignments are being included in the standardisation process at an early stage – this means that connectors are compatible worldwide and users enjoy a high degree of reliability.

New connection concepts are also required as electronic devices are becoming increasingly more compact, and the power demand is simultaneously increasing. The demands placed on connection systems for motors and drive solutions are also changing. Here, the connection system must be compact and flexible, so that it can fit into often restricted spaces. Economic aspects also play a role in this context as the connection system has a significant impact on the overall costs – especially for compact motors with integrated electronics.

Phoenix Contact developed the new “M12 Power” connector solution to connect compact motors and devices. The product family extends the M12 concept to allow the connectors to transfer power at 630 V AC and a continuous current of 12 A. As a consequence, a gap has been closed so that users can now use M12 connectors across the board for transferring signals, data, and power.

Safety as priority


Figure 2: M12 connectors for line voltages have a protective conductor connection, leading PE contact, as well as grounded knurled screw.

The connectors from the M12 Power series are mechanically coded. This prevents M12 Power connectors from being accidentally inserted into a "normal" M12 sensor connection. The clearances and creepage distances of the connectors correspond to the specifications laid down in the standards for classic power connectors. The products that are designed for line voltages have a protective conductor with leading PE contact (Figure 2).

High power rating and small size

The new power connectors are designed for supplying devices in different application areas. They have 4 power contacts with T coding for DC low-voltage applications up to 63 V and 12 A (Figure 3 – Left). They have 3 PE power contacts with S coding for AC applications involving line voltages up to 630 V and 12 A (Figure 3 – Right). As a consequence, the M12 series has been expanded to include two additional codings, allowing it to address many new application areas. With a diameter of approx. 16 mm, the product dimensions still correspond to the usual, compact M12 design.


Figure 3: T coding and S coding: T coding is for low-voltage connections up to 63 V – to supply power, for example, to fieldbus components, passive distribution boxes, power supplies, or small motors with continuous currents of up to 12 A (left). With the S coding, line voltage connections can be established up to 630 V at 12 A for compact distributed components via M12 connectors – for example, motors, frequency converters, motor-operated switches, or power supply units.

In automation technology, compact devices that are used in harsh environments generally have cables equipped with M12 connectors. The connection for the device supply was always a weak point. If the power rating of the M12 connector was not sufficient or, for safety-related reasons, a separate coding was required for the line voltage, then a conventional larger power connector had to be selected, to the detriment of compact device dimensions.

The new M12 Power connectors have now solved this problem. They offer device manufacturers significant cost advantages, as the high design and production-related costs incurred up until now when using both M12 and larger power connectors are a thing of the past. A unified M12 solution with sensor, data, and power versions simplifies the mechanical design as a result of the compatible dimensions when designing devices with M12 technology. In turn, this allows devices to be produced at lower costs.

Users also profit from the standard handling of M12 connectors, which are equipped with the Speedcon quick locking system from Phoenix Contact. In installations where space is extremely restricted, all of the device connectors can be quickly and reliably locked by just twisting them through half a turn.

New application areas


Figure 4: The 360° shielding protects the power connectors from EMC interference.

M12 power connectors also fulfill the requirements relating to compact, flexible, and cost-effective power connectors, resulting from the miniaturisation of drives and distributed cabling. M12 Power connection systems make a lot of sense, especially for devices with small mounting dimensions and operating voltages up to 630 V, but which "only" require currents in the range of 12 A. A 360° shield design protects against EMC interference (Figure 4).

New concepts for supplying power to distributed devices are possible also in the low-voltage supply range below 63 V by using the 4-position M12 connectors. These types of devices include fieldbus modules, valve islands, and power supply units in the IP67 environment. The 4-position DC version allows two independent DC supply circuits to be configured, each rated at 12 A. As a result of the 1.5 mm² conductor, this arrangement permits higher currents to be conducted with a lower associated voltage drop.


The M12 transformation artist has once again proven that it can comply with the ever-increasing demands in automation technology. For the first time, a connection technology is available for sensor, data, and power exclusively using M12 connectors. This new function supplements the universal, basic properties including simple handling and a high degree of ruggedness. As a consequence, M12 connectors have all of the features that will allow them to continue to establish themselves in important application areas; for instance, in drive and building technologies, infrastructure, and outdoor applications.