Operation in particularly harsh environments

Modules with degree of protection IP67 cannot be used in areas exposed to permanently high levels of humidity, in applications with drilling emulsions and cutting oils, or when cleaning with high-pressure cleaners. The answer for these applications is provided by the expansion of the K60 compact modules with the K60R module with degree of protection IP68/IP69K.

The K60R modules are connected instead of the AS‑Interface flat cable using a round cable with an M12 cable box. The AS‑Interface bus cable and the 24 V DC auxiliary power supply are routed in this case in a shared round cable.

Degree of protection IP68 permits many new applications, which were impossible with the former field modules with degree of protection IP67. In applications such as filling plants or machine tools, the K60R with degree of protection IP68 enables the module to be used directly in zones exposed continuously to increased humidity. It is thus possible to make even more consistent savings in wiring with AS-Interface. For more information on IP68 test conditions, see section "IP68/IP69K tests".

Cleaning with high-pressure cleaners, such as is regularly required in the food and beverages industry for instance, is possible without difficulty (IP69K).

In applications with tow chains, many users rely on placing the AS‑Interface bus cable in a round cable. With the K60R module, there is a round cable connection for direct connection to a round cable. No adapter is required.

Assembly/installation

The same mounting plates are used as for the K60 modules. Instead of using flat cables, the K60R is connected using a 4-pole round cable with an M12 connection. With the K60R, the mounting plate thus serves only as a fixture and ground terminal.

Addressing

Addressing is performed using the same socket as for the bus connection. The module is connected to the addressing unit via a 3-pole standard M12 cable.

After mounting, the module is connected with the addressing cable to the addressing unit, and addressed. The addressing cable is then removed and the module connected to the bus cable.

Connection

K60R connection options

In the IP67 environment, the field-proven standard components are connected using flat cables. Spur lines are laid into the IP68 environment by means of an AS-Interface M12 feeder (3RK1901‑1NR..). The module is connected via a round cable with an M12 cable box. For this purpose the module has an M12 bus connection instead of the previous addressing socket. The AS‑Interface bus cable and the 24 V DC auxiliary voltage are routed together in a 4-pole round cable. There must be no ground conductor in this round cable. Connection to ground is made through the mounting plate.

In the IP68 environment, only cables with extruded M12 plugs may be used.

To connect more than one K60R module to one spur line, the spur line can be split again using a T distributor (3RK1901‑1TR00) with the IP68 degree of protection.

Please note the following boundary conditions:

• The configuration guidelines for AS‑Interface generally apply. For all M12 connecting cables, the maximum permissible current is limited to 4 A. The cross-section of these cables is just 0.34 mmІ. For connection of the K60R modules, the aforementioned M12 connecting cables can be used for the spur lines. The voltage drop caused by the ohmic resistance (approx. 0.11 О©/m) must be taken into account.
• For round cable connections with shared AS‑i and U_AUX in a single cable, the following maximum lengths apply:
  • Per spur line from feeder to module: max. 5 m
  • Total of all round cable segments in an AS-Interface network: max. 20 m

Tests IP68/IP69K

K60R modules were tested with the following tests:

• Stricter test than IP67: 90 min at 1.8 m depth of water (IP67: 30 min at 1 m depth of water)
• Salt water test: Five months in salt water, 20 cm deep, at room temperature
• Test with particularly creepable oil: Five months completely under oil at room temperature
• Test with drilling emulsion: Five months at room temperature (components of the drilling emulsion: Anionic and non-ionic emulsifiers, paraffinic low-aromatic mineral oil, boric acid alkanolamines, corrosion inhibitors, oil content 40 %)
• Test in oil bath (Excelence 416 oil) with alternating oil bath temperature: 130 cycles of 15 to 55 °C, two months
• Cleaning with a high-pressure cleaner according to IP69K: 80 to 100 bar, 10 to 15 cm distance, time per side > 30 s, water temperature 80 °C

To simulate requirements as realistically as possible, the modules were artificially aged prior to the tests by 15 temperature cycles of -25/+85 °C. During the test, the modules were connected to 3RX1 connecting cables. Unassigned connections were closed with 3RK1901‑1KA00 sealing caps.

Note:

Sealing caps and M12 connections must be tightened with the correct torque.