The MECT MPT91 M1 is a single-loop microprocessor temperature regulator in a compact 48×48 mm panel-mount housing. It combines a dual LED display—red for the process value (PV) and green for setpoint (SP)—with four front keys for intuitive parameter programming. The universal input stage accepts thermocouples (J, K, S), Pt100 resistance thermometers, and standard analog signals (0/4–20 mA, 0–10 V), covering temperature ranges from −40 to 800 °C for RTD sensors and up to 1,200 °C for Cr/Al thermocouples. A user-programmable PID algorithm with self-tuning capability automatically learns the optimal control parameters during start‑up, while the soft‑start function limits the initial power to reduce thermal shock on heating elements. A dedicated PID menu allows direct access to proportional band (0–F.S.), integral time (0–6,000 sec) and derivative time (0–600 sec).

Single-Loop, Multi-Sensor & Universal Input

• One Input for All Sensors: The input type—thermocouple, RTD, or linear analog signals—is selectable from the front keyboard without hardware modification.
• Stable Measurement: An automatic cold-junction compensation ensures accurate thermocouple readings, while a configurable transducer power supply on terminal 3 can feed external 4–20 mA transmitters.
• Thermal Stability: With a rated accuracy better than 0.5% and thermal drift limited to 50 ppm/°C, the MPT91 provides repeatable process control.

Intelligent PID Control & 3-Program Sequencing

• Self-Tuning PID Server: The integrated self-tuning algorithm automatically determines optimum PID constants during initial heat‑up, eliminating trial‑and‑error tuning in the field.
• 3 Programs × 8 Steps: The controller can store up to three independent temperature profiles, each containing up to eight segments. This allows pre‑programming of ramp/soak cycles for multi‑step thermal processes without external PLC commands.
• Soft-Start: When enabled, the controller gradually raises the output power to the setpoint, protecting the heaters from inrush current and extending their service life.
• Servomotor Control Drive (Option): Models configured for servomotor output can directly drive motorized valves for gas burners or process control applications requiring proportional actuator positioning.

Specifications, Installation & Dimensions

• Main Control Output: Relay (NO) rated 5 A at 250 Vac, suitable for direct switching of contactors and solenoid valves.
• Alarm Relay (Optional): One independent relay (NO, 5 A at 250 Vac) provides process, deviation, or band alarm protection.
• Analog Output (OAP Option): 0–10 V, 0–20 mA, or 4–20 mA retransmission signal with 12-bit resolution.
• RS485 Serial (Option): Galvanically isolated RS485 half-duplex interface supporting ASCII or MODBUS RTU protocol for integration with PLCs and SCADA systems.
• Remote Setpoint (RSP Option): An external contact enables a second preset setpoint value.
• Power Supply Options: 20–30 Vac/Vdc or 90–260 Vac/Vdc (5 W).
• Physical: 48 × 48 mm front panel, 96 mm depth, 45.5 × 45.5 mm panel cut‑out, weight 150 g.

Applications

• Packaging machinery, heat‑sealing bars and shrink‑wrap tunnels
• Plastics extrusion and injection molding barrel temperature control
• Motorized valve positioning for heating/cooling circuits
• Multi‑step batch processes requiring ramp/soak temperature profiling
• General industrial temperature control where compact footprint and flexible input/output are required