Circular connectors

What are circular connectors?

A connector as an important component in electrical engineering enables you to easily connect cables to a piece of equipment and detach them again at any time.

Electrical connectors are available in every conceivable design. In addition to circular connectors, viewed from the front, rectangular, oval and trapezoidal connectors are common in the industry. Connectors with a circular connector face are also used in the domestic sector. Every traditional household socket is round. But what is the difference between circular household connectors and circular industrial connectors?

If there is no specific standard, industrial connectors are developed and tested in accordance with IEC 61984. The standard refers to "connectors", while the term plug is commonly used. This connector standard takes into account the higher requirements for electrical connectors used in industrial applications. For industrial connectors, higher-quality materials are usually used compared to the cost-effective household connector. Industrial connectors tend to have higher power reserves. They are also more robust and better protected against harmful environmental influences.

But not all circular connectors are the same! In the EPIC® circular connector product group, we at LAPP offer you an extensive product portfolio so that you can find the perfect circular connector for your application. The circular connectors are also known by their designation for the respective product family, such as M12 circular connectors or M23 circular connectors. Delve into the interesting world of circular connectors and become an expert when it comes to circular connectors!

Where are circular connectors used?

Certain circular connectors have established themselves in some industrial applications. The M17, M23, LS1, LS1.5, LS3 families are very often used in electric motors, especially servo motors. The advantage is obvious: the connector for this application must be as small as possible, resistant to vibration, robust, EMC protected and also resistant to moisture, oils and dust. This is why EPIC® circular connectors from LAPP are very often used in servo assemblies. Due to their advantages, circular connectors can be found in a wide range of industrial environments where automated control of complex processes plays an important role:

• Mechanical engineering
• Energy technology
• Production systems in the automotive industry
• Conveyor technology
• Food industry
• Industrial robots

What circular connectors does LAPP have?

Circular connectors are available as single and multi-pin power connectors and as multi-pin signal connectors. Our EPIC® circular connector portfolio is divided into three product segments:

The EPIC® SIGNAL connectors provide reliable protection against electromagnetic interference thanks to their full metal housing and an integrated EMC cable conduit. The braid shield of the cable is precisely and securely connected to the connector. The currents created in the cable shield by electromagnetic radiation or potential difference are thus safely diverted via the connector.

EPIC® SIGNAL connectors are available in sizes M17, M23 and R3.0 (M27).

EPIC® POWER connectors are used in harsh industrial applications where the outer dimensions of the plug need to be as small as possible. The servo motor application is also typical here. These motors can be found in robotics applications, all kinds of production machines and even plants that need to be small. EPIC® POWER connectors are available in sizes M12, M17, LS1 (M23), LS1.5 (M40) and LS3 (M58).

EPIC® POWERLOCK circular connectors are single-pin and are color-coded and geometrically coded to prevent incorrect connections. EPIC® POWERLOCK connectors are suitable for applications up to 400 A (screw connection) and 660 A (crimp termination).

What are the benefits of circular connectors?

EPIC® circular connectors have a very compact design. The common series are fully metallic and also metallically conductive. This is important for good protection against electromagnetic interference. Unwanted currents on the cable shield are thus diverted via the metallic conductive connector. The circular connector design also provides seals on the inside and thus provides better protection against mechanical and chemical influences.

The industrial environment in which circular connectors are used requires a robust design that can withstand damage from liquids, dirt, extreme temperatures and mechanical influences. Circular connectors can thus be used for applications in harsh environments where reliable components are required.

How are circular connectors built?

Each connector design consists of a housing, an insert (also known as the insulating body) and the matching pin or socket contacts.

The main function of the housing is to protect the electrical connection and the contacts. Environmental influences such as the penetration of foreign bodies (dust), liquids (water, oil or chemical substances) or the ambient temperature can impair the electrical connection. The housing also serves for mechanical stability, i.e. its ability to withstand mechanical influences such as external shocks and vibrations that can facilitate tear, breakage, wear or other damage.

The housings for our EPIC® circular connectors are made of metal or plastic. The metal housings have a conductive coating. This design ensures that the actual electrically conductive part of the connector is safely protected against electromagnetic interference. The plastic housings do not offer the option of connecting a cable shield and are therefore used with unshielded cables. However, the high-quality plastic also provides excellent protection against mechanical and chemical influences.

The contact insert is used to securely hold and secure the contacts. Here, the quality of the plastic used and a solid design of the contact insert are crucial for a long and reliable service life. Thanks to high-quality materials, leakage currents along the plastic surface are minimized and disruptive discharges are safely prevented.

The contacts – the actual current transmitters – are fixed in the contact insert. These are floating to compensate during connection and to minimize insertion forces. The contact area where the pin and socket contacts meet (between two connectors) and the contact area where the conductor is connected to the contact (between the cable and connector) are particularly important.

What pole configurations are found in circular connectors?

The way contacts are arranged in a contact insert is referred to as a pole configuration. The number of poles available depends on the number of contacts that can be used in a connector. Only as many contacts as there are maximum poles can be installed. If a pole configuration has, e.g. 7 poles, up to 7 contacts can be installed – but not more.

EPIC® circular connectors are available with different pole configurations, which result from the different configuration, number and type of contacts.

In general, the following applies:

Example pole configuration designations and their meaning

What designs are there for EPIC® circular connectors?

The EPIC® circular connectors are available in a wide range of variants. Its external appearance – i.e. whether a circular connector is straight, angled, with a coupling nut or outer thread, with or without a fastening flange – is called the design. Use our design overview to find the right design for your application.