PS Automation (Germany) Actuators: PS-AMS Intelligent Control & PSL/PSQ Series

The PS-AMS intelligent control concept

PS-AMS introduced a new concept in actuator applications: a microprocessor-based design with dedicated hardware and software delivering intelligent control of electric actuators — configuration of control commands, position-PID function selection, variable full-stroke speed, sixteen-point characteristic curve setting, motor temperature storage, self-diagnostics of operations — covering virtually all electric actuator application modes.

Product introduction

PSL and SQ actuators are products of PS Automation GmbH (Germany). PS-series electronic actuators modulate and open/close pipeline valves and dampers. Key features:

• Integral design: position transmitter and servo amplifier fit inside the actuator; accepts 4–20 mA command, outputs 4–20 mA or 1–5 VDC feedback; self-diagnostics; easy to use and calibrate.
• Modular function design: combinations from simple to complex control.
• Simple, compact, lightweight; CNC-machined mechanical parts.
• Low-backlash sealed gears: efficient, quiet, long life, maintenance-free.
• Multiple speeds for various control systems — fast response and stability.
• PSL: flexible disc-spring connection to the valve isolates stem/actuator misalignment; preset closing force ensures tight closure.
• PSQ: torque-switch protection prevents stem damage from excessive torque.
• High-energy rare-earth synchronous motors: smooth, compact, high torque, stall-resistant, precise.
• Split-range control: one controller drives two actuators with dual time-proportional signals (4–12 mA / 12–20 mA).
• Sealed multi-turn precision potentiometer feedback: small, accurate, minimal dead band, long life.
• Adjustable stroke for easy valve coupling.
• World-brand electrical components throughout.
• Rigorous wiring fully separated from the drive train for reliability.

Construction

Wiring is rigorously separated from the drive train; CNC-machined low-backlash sealed gearing is efficient, quiet and stable — no resonance from process fluctuations.

PSL linear actuators consist of electrically isolated control and gear sections with the motor between them: motor torque passes through multi-stage gears to a self-locking trapezoidal screw converting torque to thrust; a anti-rotation pin and radial lock act as position indicator; stroke is limited by two main limit switches and adjustable mechanical stops.

PSQ part-turn actuators use a planetary output stage (the hollow gear has three fewer teeth than the second stage — three teeth per revolution) with a constantly meshed worm, allowing direct handwheel operation on motor fault or unexpected torque increase. Threaded stops and limit switches set the travel per direction; a raised indicator shows valve position; unique torque switches adjust 50–100% of maximum torque for stem protection.

Selection

PS series integral electronic actuators are compact, lightweight and powerful with a built-in servo amplifier — widely used for on/off and modulating control of valves and dampers.

(1) PSL linear actuators

Max. stroke 100 mm, max. thrust 25 kN — for linear valve on/off and modulating duty. Main specifications:

(2) PSQ 90° part-turn actuators

Output torque 50–700 Nm for 90° valves (ball, butterfly) and dampers. Main specifications:

(3) PSAP4B servo amplifier and options

PSAP4B is an electronic proportional servo circuit (SMT): it compares the 4–20 mA command with the actuator position and drives open/close to balance position with input; it also provides an isolated 4–20 mA position signal. Start position and stroke are easily adjusted; direct/reverse action switchable; fail position (open/closed/hold) on signal fault configurable. Specifications: supply 220 V 50 Hz; consumption 5 VA; switch capacity 150 VA (24 V, 50 VA); input 4–20 mA; input impedance 150 Ω; output 4–20 mA (active isolated); load ≤350 Ω at 4–20 mA; insulation 100 MΩ (500 VDC); repeatability ±1%; sensitivity ±(0.5–5%) FS.

Extra travel (2WE) and torque (2DE) switch sets provide two volt-free contacts (220 VAC 5A); single/dual position feedback potentiometers (POT/POT2) output 0–1000 Ω; heating resistor (HR) prevents frosting below -20 °C; the separate position transmitter PSMF is for 4–20 mA position signal only.

Other optional components:

Related reading: PS Automation brand column