June 20, 2017 — United Electric Controls (UE,) a producer of safety, alarm and shutdown technology, has added two DC-voltage switching models to its One Series Safety Transmitter (ST) line. With its ability to switch 24 VDC and 125 VDC as well as 250 VAC loads, the One Series 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 embed 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.
To address the growing demand for lower voltage switching of 24 VDC equipment, United Electric Controls has now added a Safety Relay Output (SRO) capable of handling 0-30 VDC at 6 amperes. To meet the needs of customers who were using 125 V DC equipment, most of whom are in the power industry, UE has added an SRO capable of switching 0-130 VDC at 2.5 amperes. With these additions, One Series Safety Transmitters models can now be specified for either pressure or temperature monitoring at any of the following current levels:
- 12-250 VAC @ 5 mA-5 A (Model 2SLP47)
- 0-30 VDC @ 6 A, 1.8 A Pilot Duty (Model 2SLP48)
- 0-130 VDC @ 2.5 A, Q1501 Pilot Duty (Model 2SLP49)
All One Series Safety Transmitters provide 4-20 mA NAMUR NE 43 standard output with exclusive “I Am Working” diagnostics. 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, ideal for voting logic schemes.
Instrument response time is <100 milliseconds.
About United Electric Controls
United Electric Controls (UE,) a privately held corporation founded in 1931 and headquartered in Watertown, Massachusetts, USA, is a global supplier of WirelessHART gas detectors, electronic transmitter-switches, pressure and temperature switches, transmitters, sensors and controls for the process, discrete, semiconductor, aerospace and defense industries.
