United Electric Controls: Field-based DC-control

Name *: United Electric Controls: Field-based DC-control
Description *: 
The company added two DC-voltage switching models to its One Series Safety Transmitter (ST) line. The devices can directly switch 24 VDC and 125 VDC as well as 250 VAC loads. The ST models can now provide SIL 2–certified control for many types of final elements, including pilot valves, actuators, motor controllers, and other SIS elements, without involving a DCS or safety PLC.

One Series safety transmitters reduce cost and improve safety by embedding a process sensor, logic solver, and safety relay in a single, SIL 2–certified field device. Although it looks like a traditional temperature or pressure transmitter, the ST can also switch final elements, such as valves, motors, and blowers directly from the transmitter, maximizing response time while eliminating the wiring needed to route a shutdown or alarm response through a PLC or another safety controller.

To address the growing demand for lower voltage switching of 24 VDC equipment, there is now a safety relay output (SRO) capable of handling 0–30 VDC at 6 amperes. To meet the needs of customers who were using 125 VDC equipment, most of whom are in the power industry, the company added an SRO capable of switching 0–130 VDC at 2.5 amperes.

All of the series safety transmitters have 4–20 mA NAMUR NE 43 standard output. The transmitters are certified for use in SIL 2 safety instrumented systems and are capable of SIL 3, per IEC 61508. They have configurable self-diagnostics and achieve a safe failure fraction of 98.8%. Additional low-level discrete outputs communicate health and set point status. Instrument response time is less than 100 milliseconds.
 
URL*:  http://www.ueonline.com/
Date Submitted*:  11/6/2017