AUMA ACExC 01.2 Explosion-Proof Actuator Controls

Overview

The AUMA ACExC 01.2 (AUMATIC) is the explosion-proof, microprocessor-based actuator control unit from AUMA Riester, designed for plants where potentially explosive atmospheres are likely to occur. It is mounted directly onto SAEx/SAREx multi-turn actuators and SQEx/SQREx part-turn actuators and combines integral local controls, motor switchgear, status signalling and fieldbus communication in a single flameproof housing that cannot act as an ignition source. The unit evaluates operating commands and actuator feedback signals and switches the actuator motor without delay, so that only commands and feedback need to travel between the plant control system and the valve.

In Oman and the GCC, Seven Star LLC proudly supplies the AUMA ACExC 01.2 to customers across the Sultanate of Oman and the wider GCC. Our team supports engineers and procurement leads from specification through delivery, including selection of voltage, fieldbus and certification options for the Omani oil, gas and petrochemical sector.

Operating Principle of the AUMA ACExC 01.2

The AUMA ACExC 01.2 sits between the control system and the actuator motor. Operating commands arrive through six opto-isolated digital inputs (OPEN, STOP, CLOSE and EMERGENCY), through a 0/4–20 mA analogue setpoint when the positioner option is fitted, or through a fieldbus interface. The controls compare these commands with the position and torque signals delivered by the actuator and then switch the motor via mechanically and electrically interlocked reversing contactors or, for modulating duty, a thyristor unit. Seating can be selected as limit or torque seating independently for the OPEN and CLOSED end positions, and a torque bypass with adjustable duration allows high break-away torques during start-up.

In combination with the MWG magnetic limit and torque transmitter, the AUMA ACExC 01.2 offers non-intrusive setting of the actuator: limit and torque switching points are parametrised through the local controls without opening the explosion-proof enclosure. The controls also derive two galvanically isolated analogue outputs for position and torque, store up to three torque-travel characteristics per direction, and monitor phase sequence, motor temperature, heater, operation time and number of starts. Faults and maintenance needs are reported in line with NAMUR recommendation NE 107.

Engineering Design of the AUMA ACExC 01.2

The housing of the AUMA ACExC 01.2 is built for flameproof Ex de protection as standard (II2G Ex de IIC T4 or T3 Gb, II2D Ex tb IIIC T130 °C or T190 °C Db IP6x), with an Ex d option. Enclosure protection is IP68 and the corrosion protection class is KS, suitable for coastal and highly saline atmospheres. The permissible ambient temperature range is −30 °C to +40/+60 °C. The local controls provide a selector switch LOCAL – OFF – REMOTE that can be locked in all three positions, push buttons for OPEN, STOP, CLOSE and RESET, six indication lights including a Bluetooth indicator, and an illuminated graphic LC display that supports status monitoring and parametrisation.

Electrical connection is made through the AUMA Ex plug/socket connector (KT) with screw-type motor terminals and push-in control terminals; terminal-block versions (KES) are available for increased safety Ex e or flameproof Ex d. The controls can be mounted integrally on the actuator or separately on a wall bracket, and an external 24 V DC supply of the electronics is available as an option so that the control logic remains alive when the mains supply is switched off. Cable entries are offered in metric as standard, with Pg, NPT and G threads as options.

Key Features

The following features make the AUMA ACExC 01.2 the reference control platform for hazardous-area valve automation:

• Explosion protection to ATEX with DEKRA certificates for combination with SAEx and SQEx actuators, plus FM and IECEx approvals for international installations.
• Illuminated graphic LC display and lockable local controls give operators clear status information and safe local operation directly at the valve.
• Bluetooth 4.2 interface with a range of up to 10 m allows commissioning and diagnostics from a notebook or Android and iOS device through the AUMA CDT and AUMA Assistant App.
• Optional positioner and PID process controller accept 0/4–20 mA setpoints, with programmable behaviour on loss of signal, split-range operation and adaptive dead band.
• Fieldbus control via Profibus DP/DP-V2, Profinet, Modbus RTU, Modbus TCP, Foundation Fieldbus, HART and WirelessHART, including component-redundant interfaces and FOC connection.
• Programmable EMERGENCY behaviour, interlock functions and Partial Valve Stroke Test (PVST) to verify actuator and controls on demand.
• Comprehensive operating data logging with resettable and lifetime counters and a time-stamped event report with history.
• Safe end position feedback up to SIL 2 in selected configurations, with a dedicated SIL version available for safety instrumented functions.

Industrial Applications

Hazardous-area valve automation is a daily reality for oil and gas, petrochemical and LNG operators in the Sultanate of Oman. The AUMA ACExC 01.2 is a natural fit for tank farms, pipeline manifolds, refinery process units and offshore-supply terminals around Sohar, Duqm and Salalah, where ESD valves, isolation valves and modulating control valves must be operated from the control room yet remain fully operable locally. Its thyristor option suits modulating duty on process control valves, while the standard reversing contactors serve open–close isolation service. In coastal installations the KS corrosion protection and IP68 enclosure withstand salt-laden air and extended exposure to humidity.

In Oman and the GCC, Seven Star LLC supplies the AUMA ACExC 01.2 together with matching SAEx and SQEx actuators, wall brackets and cable sets, plug/socket connectors and commissioning tools for refineries, gas processing plants, fertiliser and chemical complexes, and the Muscat and Sohar industrial zones. Water and power utilities with hazardous classified areas, such as biogas, fuel storage and chlorine handling, also rely on explosion-proof controls of this type. For projects that combine the AUMA ACExC 01.2 with other drives or controls, Seven Star LLC also supplies the AUMA MATIC AM/AC integral actuator controls, the AUMA AMExC 01.1 and the AUMA SAEx explosion-proof actuator.

Technical Specifications

The table summarises the main data of the AUMA ACExC 01.2 as published in the AUMA technical data sheet; the complete data sheet is available for download on this page.

Request a Quote for AUMA ACExC 01.2

To request a formal quotation for the AUMA ACExC 01.2, submit an RFQ through this page with the actuator type, supply voltage, required fieldbus interface and hazardous-area classification. Seven Star LLC can confirm availability and lead time, arrange matching AUMA actuators and accessories, and provide the technical datasheet for download. Contact our instrumentation division in Muscat for engineering support. In Oman and the GCC, Seven Star LLC supplies products on request with local technical support.