Technology Showcase: Safety First
EP Editorial Staff | November 15, 2013
Are You Overlooking Some Common Safety Problems?
At least two seemingly benign hazards lurking around today’s operations could be just a damaging as arc flash. Do your maintenance teams have the knowledge and skills they need to deal with these concerns?
We are all familiar with potential hazards relating to arc flash and other electrical incidents. But what about other safety issues that plants and facilities face? Some common, yet often overlooked, safety issues include those relating to pressure and pressurized systems. These include boilers and their associated distribution systems and high-pressure refrigerants. While this is not a complete list, it’s worth noting that incidents involving these types of systems and products are just as important and potentially hazardous as any arc flash incident.
Boiler system concerns
Boiler accidents can result from faulty pressure-relief valves, low water levels or corrosion to metal components caused by improper water treatment.
- If a pressure valve malfunctions because of corrosion or lack of testing and recertification, it can fail to open or relieve its designed capacity of steam or hot water. The pressures and temperatures in the boiler will then build above design specifications and a pressure-vessel failure will occur.
- If the water level in the boiler drops and exposes the boiler tubes, overheating can occur and lead to further damage to the boiler—possibly causing it to explode.
- Over time, without proper water treatment, water may become corrosive and scale may form on the heating surfaces, which in turn can cause damage to the structural integrity of the boiler itself.
- Finally, improper maintenance may also cause pressure problems and is a common cause of boiler accidents.
High-pressure refrigerant concerns
Similar to boilers are issues concerning high-pressure refrigerants. One such refrigerant—R-410A—is of particular concern: Although it does not have the ozone-depleting effects of traditional refrigerants, R-410A operates at 40% to 70% higher pressures. That means operators must be exceedingly careful when working with systems that use this type of refrigerant.
- A key consideration with R-410A is to verify that equipment for which you are using it is designed for this refrigerant. This will ensure that the equipment can handle the higher pressures that are encountered when working with R-410A.
- Since most older systems weren’t designed to handle the types of higher pressures associated with R-410A, retrofitting them is not recommended.
Using proper equipment and proper and scheduled maintenance, facilities can avoid many of these accidents before they happen. For more information on these and other workplace-safety issues, as well as related real-world plant, building and facility maintenance training programs, visit: americantrainco.com.
Full-Time, Advanced Arc-Flash Technology
According to GE, its ArcWatch technology offers full-time, automatic, always-on protection and reliability for people, property and equipment. It works through a combination of communication algorithms across the GE portfolio of circuit breakers by using instantaneous zone-selective interlocking (I-ZSI) and waveform recognition (WFR) to ensure that only circuit breakers nearest to the fault will trip, which happens in as little as four milliseconds. Systems embedded with this technology reduce the impact of an arc-flash event to <8 cal/cm2, translating into lower requirements for using personal protective equipment. ArcWatch-enabled circuit breaker families from GE include the EntelliGuard*, Record Plus* and Spectra RMS* series. Shown here, the recently launched PremEon* S trip unit used in conjunction with the Record Plus platform is an advanced electronic trip unit that provides higher levels of accuracy for selective ratings without compromising safety, especially during maintenance operations. It also eliminates rating plugs for jobsite simplicity and adjustability. Recently introduced EntelliGuard enhancements simplify in-the-field energy management and user interface with improved breaker-maintenance diagnostic information.
GE Industrial Solutions