ABB MEASUREMENT & ANALYTICS | TECHNICAL DESCRIPTION Intelligent electrical actuators for process automation applications System description Electrical actuators for positioning vanes and valves in the process control loop Combining durability and precision positioning Suitable for continuous positioning and three-step control Introduction Actuators are used in every industrial sector. In the field of process automation, they are responsible for positioning vanes and valves, etc. to control the flow of material, mass, and energy. The trend towards actuators as "intelligent field devices" is now considered to be part of the state of the art. The recent past has seen an increase in demands for functions to be incorporated within devices, as well as for connectability to bus systems and visualization of process and device data. CONTRAC has been developed to satisfy these demands. CONTRAC, a composite term based on the words control and actuator, is an "intelligent" and compact actuator. The Contrac actuator system is based on the family of rotary and linear actuators which has a sound track record reaching back 50 years or more. Its features include: • Continuous positioning • Overload-proof at end positions without the need for torque dependent switch-off • High protection class • Long service in

Intelligent electrical actuators SYSTEM DESCRIPTION | TD/ACTUATOR/001-EN REV. A Change from one to two columns … Introduction A combination of proven mechanical components and microprocessor electronics have been used to develop an intelligent series of actuators which: • Are compatible with fieldbuses as well as more traditional control methods • Support diagnostics and can be parameterized via a graphic user interface • Feature a self-monitoring facility • Enable fail-safe storage of technical data In addition to the wealth of functions offered, the three-phase asynchronous motor with its cage...

Intelligent electrical actuators SYSTEM DESCRIPTION | TD/ACTUATOR/001-EN REV. A Figure 2: Operating principles The actuator continuously responds to a setpoint signal. The motor is constantly under voltage (operating mode S9 – 100 % stallproof according to IEC 60034-1 / EN 60034-1) and gently increases or reduces the torque on the electronic unit in proportion to the ΔY signal (the difference between the Y setpoint and the Y position signal - see Figure 4). The actuator is not subject to any temperature derating, i. e., there are no restrictions, even at the maximum permissible ambient temperature....

Intelligent electrical actuators SYSTEM DESCRIPTION | TD/ACTUATOR/001-EN REV. A … 1 Operating principles Figure 5 shows the dynamic behavior of the Contrac after a setpoint change. The actuator follows the changing setpoint almost immediately, with only a slight delay. S9 specification Load profile B Actuator position w (t) = Setpoint, t = Time Figure 5: Schematic representation of a Contrac step response Thanks to the special electronics and control technology used, no temperature / torque monitoring switches are required. This operating mode, with its gentle changes in mechanical load, is one...

Intelligent electrical actuators SYSTEM DESCRIPTION | TD/ACTUATOR/001-EN REV. A 2 Devices Rotary actuators Figure 8: Rotary actuator mounted on a vane 1 Handwheel for manual operation 4 Position sensor 2 Motor 3 Plug for electrical connection 6 Output shaft 7 Spur gearing Figure 7: Cross-section of a rotary actuator Rotary actuators are available for rated torques in the range 50 to 16000 Nm (40 to 12000 lbf-ft) and all share a similar design. A motor drives low-friction, oil-lubricated spur gearing. At the end of this gearing, a lever mounted on the output shaft transmits torque to the control...

Intelligent electrical actuators SYSTEM DESCRIPTION | TD/ACTUATOR/001-EN REV. A … 2 Devices Linear actuators 2 Yoke Figure 11: RSD20 linear actuator 5 Recirculating ball screw 2 Integrated rotary / linear conversion 3 Plug for electrical connection 4 Position sensor 7 Thrust rod 8 Handwheel 9 Spur gearing Figure 10: Cross-section of a linear actuator and detailed view of the recirculating ball screw Linear actuators are available for rated forces in the range 4 to 200 kN (900 to 45000 lbf) and are also very similar in terms of their design. The motor drives the internal rotary / linear conversion...

Intelligent electrical actuators SYSTEM DESCRIPTION | TD/ACTUATOR/001-EN REV. A Electronic unit Figure 14: Electronic units for field mounting (example) 1 Electronic units for field mounting 2 Local operator panel 3 Electronic units for rack installation Figure 13: Electronic unit If the actuator provides the muscles for a positioning loop, the electronic units provide the brains. These modules can be installed in the field near the actuator (IP 66) or remotely in a mounting rack (IP 20). The integrated version is available for both the smallest rotary actuator and the smallest linear actuator....

Intelligent electrical actuators SYSTEM DESCRIPTION | TD/ACTUATOR/001-EN REV. A … 2 Devices Electrical connections As the connector housing is made of metal, this ensures a high IP rating and reliable electrical connection, even under difficult ambient conditions. Depending on the option selected, there will be either 1 or 2 terminal blocks for connecting power and signal cables. These terminal blocks can be used for both screw and clamp-type terminals. Electronic unit Figure 16: Example connection details when connecting to a Contrac electronic unit Screw terminals are used to connect cables...

Intelligent electrical actuators SYSTEM DESCRIPTION | TD/ACTUATOR/001-EN REV. A Figure 17: Wiring diagram (example based on field mounting of EBN853 / EBN861) Change from one to two columns

Intelligent electrical actuators SYSTEM DESCRIPTION | TD/ACTUATOR/001-EN REV. A 3 Communication As before, the new generation of Contrac actuators can also be controlled by conventional signals. Users who decide to install intelligent actuators will not be forced to give up their current system concept. They can also be confident that this new generation of actuators will not leave them high and dry. Contrac actuators are designed to be compatible with any new system concepts, e. g. fieldbus, which emerge in the future. Intelligent actuators are able to communicate through an RS 232 interface,...