The RCS electric actuator product line is complemented by a broad range of accessories designed to address the specialized control requirements of today's process control applications. All accessories are designed for ease of installation and calibration in either quarter-turn or multi-turn actuator models. They are available in a variety of configurations and voltages throughout the product offering.
Potentiometers
These provide a voltage or resistance signal proportional to valve position throughout the travel of the actuator. They are available in a variety of resistances and are suitable for use in all RCS models.
Interposing Relays
Interposing relays permit actuator control utilizing a control voltage (12 VDC, 24 VDC, 120 VAC, or others) which may be different from the actuator's primary voltage. A variety of contact structures are available such as SPDT, DPDT, and latching or momentary coils.
Motor Brakes
To prevent the actuator from being back-driven due to dynamic flow conditions acting on the valve or damper, motor brakes are used to hold the actuator in its desired position. Motor brakes are recommended when the actuator is installed on any flow control device that has the capability of back-driving the actuator. Brakes are available in a variety of AC or DC voltage ranges, and are suitable for quarter-turn, Spring-Return or multi-turn models of the RCS actuator line.
Heaters
To minimize the build-up and damaging effects of moisture upon electronic components of the actuator, RCS uses PTC (Positive Temperature Coefficient) heaters in the actuator enclosure; these devices are self regulating and are designed to maintain a temperature differential from the outside ambient temperature. PTC heaters with a 10 watt rating are standard in all SurePowr actuators and Electripowr actuators in 110 or 220 VAC, single phase models. In the case of extreme environmental conditions, heaters with an increased wattage output can be supplied upon request.
Local and Remote Control Stations
A varied selection of integrally mounted control boxes or remote mounted control stations can be supplied with options such as indication lights, pushbuttons and/or selector switches for local operation. In addition, control devices such as reversing contactors, transformers, monitor and overcurrent relays, and other control devices can be provided to satisfy specific automation and control requirements.
Position Transmitters
An analog feedback signal proportional to valve travel can be provided with theinclusion of the RCS Posi-Tran module. An external single phase supply source is required for this component.
Network Communication Interface Cards
Several variations of non-proprietary network communication cards are available for use in the RCS electric actuator. These cards are easily installed in the actuator enclosure and link together multiple actuators and other instrumentation in a common communications loop, allowing for more cost-efficient design and lower installation and maintenance costs. These modules are suitable for either simple on/off or modulation control and status feedback of a process loop.
The Electric Actuator Smart Controller (EASC SCC-10) card provides accurate positioning control of RCS electric actuators using an analog input signal. Setup and calibration is greatly simplified using microprocessor based technology. There are no dipswitches to set or trim pots requiring adjustment; setup is quick, convenient and easy using the EASC menu viewed on a LED display. No external meters are required for setup - once the initial menu settings are selected, the
EASC performs a self calibration procedure applying the menu selections to actual actuator performance. The calibration values are then stored in a permanent non-volatile memory. A wide variety of alarm functions, relay outputs, input and output ranges and other standard features make this module the optimum choice for specialized control applications.
Thermal Protection Blankets
For specialized, life critical applications where the actuator will be exposed to elevated temperatures for extended periods of time, thermal protective blankets are available for temperatures up to 752° F (400°C).These blankets can be installed in the field and are available for the complete range of RCS actuators.
Electronic Current Sensing
To prevent electronic components in the actuator from being damaged by excessive current draws caused by excessive torque demands, the DT-40 module monitors the motor amperage and interrupts the motor circuit supply voltage. This module is field-adjustable to accommodate various motor and voltage applications.
Position Transmitters
The Positran module transmits the actuator position using a 4-20 mAdc signal for remote indication or feedback. It converts the resistance value of the actuator position sensor (potentiometer) to a 4-20 mAdc current signal. The Positran module can be added inside of an actuator or in a control box enclosure.
Auxiliary Limit Switches
Should additional switch contacts be required for position indication, interlocks, or alarm circuits, auxiliary voltage-free switches can be added for additional circuitry. Various switch formats (SPDT, DPDT) are available and are independently adjustable throughout valve travel.
These are just some of the accessories available to tailor the RCS actuator to today's specialized process and control requirements. Other features are available to further enhance the capability and performance of the RCS electric actuator - Contact your RCS Service Center for assistance and details.
