Electro-mechanical switches, Manufacturing, Plant Safety, Safety Relays on Transmitters, Transmitters

The One Series Safety Transmitter for Increased Plant Safety

united electric safety transmitter

The power generation market is beginning to emphasize the importance of plant safety. This was made clear to all attendees during the keynote session at the Power-Gen International Show in Orlando held in early December. Ms. Kimberly S. Greene, executive VP and COO of Atlanta-based power generation Southern Company made a passionate plea for better safety standards within plants that fall under the Southern Company umbrella, and to begin thinking about plant safety and investing in safety automation technology to provide some solutions. According to Ms. Greene, Southern Company facilities sent 300 workers home with workplace injuries in 2014.

In one case this year, a 44-year employee died on the job, causing Ms. Greene to make an emotional plea to all attendees and plant managers to move safety to the top of their priority lists. For the power generation market, plant safety has not (yet) received the same level of attention when compared to the hydrocarbon processing market. Ms. Greene’s statistics reminded us all that functional safety must be considered across many industries that include harsh and hazardous operating conditions and processes.

The One Series Safety Transmitter is a pressure and temperature monitoring transmitter-switch that provides a NAMUR NE 43 standard 4-20 mA analog output. Its programmable high-capacity solid-state safety relay output enables the fastest emergency shutdowns in the industry.

The One Series Safety Transmitter was designed with features that simplify installation, improve productivity, and eliminate nuisance trips. The instrument is password protected to prevent unwanted parameter changes; eliminating the risk of tampering. The large backlit digital display provides process variable, status, self-diagnostics and field programming information.

Some of the advantages of using UE’s safety transmitter are:

  • ​4-20 mA analog output with field scaling capability
  • ​100% programmable high-capacity safety relay for switch mode, set point & deadband
  • ​Effectively replaces a gauge, transmitter, and a switch to reduce potential leak paths
  • ​Additional discrete outputs to facilitate voting logic schemes
  • ​The industries highest safe failure fraction (SFF) of 98.8% as certified for use in SIL 2 by exida

For more information on UE’s One Series Safety Transmitter, please visit our website at www.ueonlone.com or call our application engineers at +1 (617) 923-6977. You can also write us at TechSupport @ueonline.com.

Manufacturing, Plant Safety, Safety Relays on Transmitters, Transmitters

Diagnostics that Reach Beyond their Normal Boundaries

As a company known for our pressure and temperature switches, transmitters and sensors for safety, alarm and shutdown applications; we’re constantly evaluating our customers’ needs. Our range of product offerings, including the One Series Safety Transmitters, are engineered to meet and exceed industry standards.

It all started with our One Series electronic switch product line, originally introduced in the late 1990s. During focus group interviews with our customers, it was determined that these products must include self-diagnostic capability, helping to avoid the “blind switch issue” inherent in mechanical switches (which we also manufacture). In a blind switch intended for safety, customers were concerned about reliability. “How do I know if will work when I need it to?”

The blind switch issue was a major consideration when designing our One Series Safety Transmitter because when a product is “blind,” it has no self-diagnostic capability, requiring preventative maintenance to determine if it is still functional Additionally, the reduction in the number of maintenance workers leaves fewer instrument and control technicians to perform this vital maintenance, a concern for plant managers. Plant upgrade strategies now specify self-diagnostic (smart) instrumentation, such as our One Series Safety Transmitter.One Series Safety Transmitter Display

 

At United Electric Controls, we go beyond the traditional boundaries of self-diagnostic instrumentation. For example, typical smart instruments can determine if there are errors in the software, if the sensor cable is disconnected and if there is a functioning keypad to set parameters. The One Series IAWTM self-diagnostics take this concept much further and evaluate the sensor to see if it is open, shorted and still capable of sensing temperature and pressure, is there a button stuck on the keypad and the validity of the signal that is telling the switch to open. This is all important so there is reasonable assurance that the product is functioning correctly and safely.

The One Series IAWTM self-diagnostic feature also considers external influences on the operation of the product, evaluating the power that the instrument is being given, loop power or DC power supply. The One Series monitors the power supply to make sure the power is clean, and there are no spikes, drooping, or noise from radio frequencies, etc. This is all done to make sure the power source is reliable.

The One Series can also detect if the sensor is clogged and unable to read pressure. The One Series has an advanced feature called Plug Port Detection to determine if the sensor is clogged and then can report the condition as detailed below. Another external diagnostic feature involves the ability to monitor the Safety Relay Output from an external perspective. For example, if the instruction to open the SRO is given by the microcontroller, IAWTM can determine if the SRO actually opened. Line fault detection is also included to detect open and shorted wiring connections to the final element (load).When IAWTM detects a fault, three actions are taken:

  1. The process variable and IAW indicator is replaced by a message on the display, informing the I&C technician of the fault type.
  2. The NAMUR NE 43 standard 4-20 mA output will change from indicating the process variable to the fault indicating current of 3.6 mA, providing remote indication to the control system that a fault has occurred.
  3. The Safety Relay Output (SRO), SRO Status and IAW outputs will fail safe (open) within 100 milliseconds of the detected fault, initiating an emergency shutdown.

Consider the One Series family of pressure and temperature monitors for your safety, alarm and shutdown applications. Click here for more details.

Electro-mechanical switches, Plant Safety, Transmitters

Replacing Mechanical Switches in a Safety Application

Is it that time to upgrade your plant’s safety instrumentation? If your case is the typical upgrade move from mechanical switches to a transmitter, do you know specifically which type of transmitter you should be getting? What is the best means of replacing mechanical switches in a safety application?

united electric safety transmitterIt’s often necessary to replace mechanical switches because they are considered blind devices; they cannot warn you when they have become faulty, nor can they be relied on completely, as they have many moving parts. This can result in the sensor cracking, the piston sticking, or the micro-switch wearing out. Unless the switch is tested on a regular basis, there is no way to determine when problems exist. This is the main reason many facilities are moving towards transmitter upgrades.

Typical transmitters, however, can be very costly for a plant. Not only is the instrument itself expensive, but there are many hidden costs as well. A transmitter will require major input to the control system, including analog requirements, cabling, and the reprogramming of the control system to accommodate the updated continuous signals that process pressure changes. With all of this, the programming tasks become increased.

By now, you should realize that United Electric Controls places safety and quality above all else. So what would we recommend using instead? Our One Series Safety Transmitter. Since the One Series Transmitter contains a built-in switch function and has a self-diagnostic feature, programming would remain the same in the upgrade process. This way, you are saving money and time in the upgrade process without compromising an ounce of safety.united electric safety transmitter 2

We designed the One Series Safety Transmitter from the ground up with the intent to use it specifically in safety applications. In comparison, other transmitters are meant for process applications, meaning accuracy is high but not necessarily functional for safety situations. When it comes to safety, high quality, designed safety transmitters are the best option to go with.