The Society of Automotive Engineers (SAE) has developed a new specification – SAE J 2839 – for the use of interconnection devices in harsh environments, so in response Amphenol has launched a new high speed SAE J 2839 compliant version of the M12 connector. Andy Sleeman, business development director, Heavy Equipment – Hybrid and Energy Storage, Amphenol Industrial, looks into the technology.

High speed transmission connection systems have traditionally been implemented into commercial applications – such as factory automation, machine data transmission, and other communication between sensors and computers that require a high speed connector – yet pay little regard to high vibration, high temperature and overall harsh environmental demands. With the increased implementation of these high speed data link connection systems into more heavy duty environmental surroundings, the need for a more robust and ruggedised connection system has surfaced.

The M12 form factor has been an industry-standard connection system for light industrial applications for many years, and was developed to meet the needs of harsh industrial environments where there is the possibility of exposure to heat, oil and moisture.

Compact and reliable, the M12-style circular connector is in compliance with IP67 and is based on the IEC 61076-2-101 specification. It is available in four-, five- or eight-pin count with current ratings varying from 1.5A to 4.0A, making it suitable for a variety of interconnection applications.

With the many advances in technology, high speed digital transmission has now found its way into heavy equipment, rail and mass transit, and unprotected process control applications. Data link connectors are now required to shift out of the ‘safe’ environment of industrial applications and move into the realm of harsh surroundings. In response to this, the Society of Automotive Engineers (SAE) developed a new specification – SAE J 2839 – for the use of interconnection devices suitable for such environments.

On learning about the latest specification, the design engineers at Amphenol developed the Max-M12, an SAE J 2839 compliant version of the M12 connector. 

For harsh environments

Available in two basic physical configurations, a 90° right angle connector and a straight version, the Max-M12 provides a customised solution that includes just the connector mating pair or the complete cable assembly and options to over-mould the cable assembly. Both configurations are available in four- and five-pin configurations with B, D and P polarity codes in line with the IEC 61076-2-101 specification. They are capable of being terminated into 0.8mm2 (18 AWG) or 0.5mm2 (20 AWG) wires defined by SAE J1128 as well as 0.75mm2 or 0.50mm2 conductors as defined by ISO 6722.

The connector system is IP67 and IP69K compliant, making it dust and waterproof, and resistant to high pressure and high temperature wash downs. It can withstand temperatures ranging from -40°C up to 125°C, while maintaining its current rating of 4A at 250V (for four-pin) and 60V (for five-pin).  Furthermore, it can also endure crush environments and pulling/tugging of cable assemblies with pull forces ranging from 100 lbs to 300 lbs.

It is housed in a HDM 12 EX version impact resistant metal shell, ensuring its performance in extremely rugged environments and harsh conditions. The housing is retained using an M12 thread that has an optimum tightening torque of 0.8N-m to 1.0N-m.

Considered the most durable data link connector in its class with connector retention forces of 444N and contact retention forces of 110N tested 50 cycles per minute, the Max-M12 has undergone extensive intense vibration testing with forces up to 20 times gravity oscillating at a frequency of 10Hz to 2,000Hz, and shock testing of forces jerking the connector at 50 times gravity, 10 times at a go.

Of additional benefit, the connector’s electrical insulation provides a resistance of over 20 megaohms, while withstanding a high temperature of 125°C for 1,000 hours. Both electrically robust and physically strong, it boasts a dielectric withstanding of 1,000V and is rated for an impulse voltage of 1,500V. Max-M12 for both cable-to-cable and cable-to-device is backward compatible with the original M12 connector and the IEC 61076-2-101 specification with a higher environmental rating. The contacts are rated at less than 10 milliohms each with a maximum millivolt drop of 50 millivolts.

The Future is now

As technology continues to evolve, designers and engineers will continue to work hard to meet the standards set forth by the SAE. These standards play a key role in improving safety, reducing costs, increasing productivity, providing market access and advancing new technologies. By working together and following the standards created, designers and engineers are able to pave the way to a promising future.

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