At its September technical strategy meeting, PROFINET International (Pi) decided that the L-coded variant, standardized worldwide by standard 61076-2-111, will be the sole standard for future 24-volt PROFINET devices with round connectors. Key factors behind this decision were its compact design and its ability to transmit high currents (16 A) on a conductor with a cross-sectional area of 1.5 mm².
Furthermore, M12 power connectors with L code for PROFINET devices in a TN-S system can be connected via the fifth contact for functional earthing to a common bonding network (CBN), a mesh earthing concept compliant with DIN EN 50310.
The current PROFINET guideline, "PROFINET Cabling and Interconnection Technology," specifies two round connectors with screw connections for the 24-volt power supply, in addition to a rectangular push-pull connector. This is an M12 connector with code A for class 1 to 4 A power supplies, while the version with a 7/8" connection is for class 2 to 16 A power supplies.
Uwe Widmann, head of standardization and technology at Belden, Germany, explains that: "In the future PROFINET guideline, which is expected to be published in April 2017, these two variants will be replaced by M12 power connectors with code L.".
"This connection technology is more powerful and almost 50% smaller than other comparable power connectors. This miniaturization has also been applied to PROFINET devices, so future PROFINET networks can be created more flexibly and efficiently.".
Lumberg Automation's M12 L-coded power connectors are UL and VDE approved and are available in straight, angled, and molded versions for customer assembly or installation. They feature an extended operating temperature range of -40°C to +125°C and are available in IP65, IP67, or IP69K protection classes. The 5-pin versions with functional earthing are easily identifiable by their gray cable sheath and gray contact carriers for the pins and sockets.
