United Electric Controls is pleased to announce an exciting new model now available for the One Series Electronic Switch product line. Along with the One Series 2-Wire discrete input-powered models, we now offer a variation that is powered from a 4-20 mA loop, much in the same way a 2-wire transmitter is powered - directly from the analog input of a PLC or DCS.

The One Series model 2WLP provides an analog signal to the PLC or DCS input that varies proportionally with changes in the process - just like a transmitter - it is a transmitter. The 4-20 mA output is field-scalable, providing a 2:1 turndown capability.

In addition to the transmitter output, there is an auxiliary solid-state relay (SSR) switch with fully programmable set point and deadband. Some applications may not require a switch function, so it is not necessary to make any connections for the SSR and only 2 wires are needed to connect the instrument. Other applications require a SSR output to switch loads locally (close to the point of measure) while the 4-20 mA signal is sent back to a control room for remote monitoring and trend analysis. This configuration requires 4 wire connections but no separate power wiring. Power for all functions is provided by the 4-20 mA input connection.

The SSR is available in two switch ratings:

• Model 2WLP41 incorporates a 0-140 VAC and VDC SPST contact rated at 0.6 A
• Model 2WLP43 incorporates a 0-280 VAC and VDC SPST contact rated at 0.3 A

The One Series 2WLP has the potential to replace 3 instruments with one - a switch (the 2WLP has a SSR), a gauge (the 2WLP has a digital display) and a transmitter (the 2WLP has a 4-20 mA proportional output). When you consider the elimination of leak paths and vessel penetrations, the cost savings of replacing 3 instruments with one, less shop time and less installation labor, the One Series 2WLP excellent value proposition becomes increasingly obvious.

The new One Series model 2WLP is available with all of the sensor options associated with One Series models 2W2D, 2W3A and 4W3A, including the new lower-cost wet/wet differential pressure with inches of water column range (use option M275).

Please check the One Series Bulletin for additional information and specifications.