Limit Switch for Rotary Positioner - PTL7R | OMC

OMC PTL7R – Limit Switch Boxes for Rotary Positioners

The OMC PTL7R is a limit switch box, optionally with a 4–20 mA position transmitter, designed for rotary valves and pneumatic actuators. It mounts on actuators with NAMUR interface or directly on OMC positioners, using axial coupling to minimize mechanical backlash in position feedback.

Construction and Operation

Enclosure is made of cast aluminum with anti-corrosive coating. Standard ingress protection is IP65. The unit does not contact process media; selection is based on signal type, PLC/DCS input, ambient temperature, and mechanical compatibility with the actuator, not valve PN/Class.

Signal Variants

• PM2R / PM2L: two pneumatic NC limit switches, supply 0–8 bar, tubing connection 4×2 mm, 0–90° angle, temperature -20…+60°C.
• EM3R / EM3L: two electromechanical SPDT switches, PG9 cable entry with internal terminals, temperature -25…+105°C.
• I20R / I20L: two-wire inductive switches per EN 60947-5-6 / NAMUR, supply 8.2 V, temperature -25…+70°C.
• I30R / I30L: three-wire inductive PNP NO, 10–30 V DC, switching frequency 1000 Hz, temperature -25…+70°C.
• TN0R / TN0L: position transmitter 4–20 mA, supply 24 V DC, consumption <0.65 W, temperature -20…+70°C.

Adjustment and Applications

Adjustment is via cams at the valve end positions, typically 0–90°. For analog variants, 0% is set at 4 mA and 100% at 20 mA.

Typical applications: butterfly valves, ball valves, OMC positioners, instrument air, water, steam, or auxiliary chemical skids, where local indication and electrical or pneumatic position feedback are required.