4 FM quick reads on power
1. Diagnostic and Monitoring: Tools to Analyze Power Quality
This is Chris Matt, Managing Editor of Print & E-Media with Maintenance Solutions magazine. Today's tip is using diagnostic and monitoring tools to analyze power quality.
Increased demands for indoor air quality (IAQ) have resulted in the need for technicians to more closely monitor and document conditions in buildings. While centralized automation systems can monitor overall conditions in a building, most IAQ problems are localized. Detecting and addressing these problems requires the use of monitoring equipment.
The latest generation of portable IAQ monitors allows technicians to measure carbon monoxide, carbon dioxide, relative humidity and temperature. They also can record particle counts, measure volatile organic compounds, determine airflow, and measure differential pressure. Technicians can collect data and read it from the unit or upload it to a laptop computer for analysis.
But looking beyond IAQ, technicians also are using monitoring technology to analyze power quality. As more facilities use electronic and computer-based systems to monitor operations, they will require greater amounts of high-quality, stable power. Problems such as sags, spikes, transients and harmonics can easily disrupt the operation of this equipment.
Traditionally, it was difficult to track the causes of these problems. New-generation, portable equipment has improved to the point where technicians can use it to measure and log current, voltage, power factor and energy, while watching for voltage transients and other related problems.
Units offer cycle-by-cycle power analysis and can identify transients depending on the sampling rate, with the more sensitive units offering up to 512 samples per cycle. Most units offer eight sampling channels — four for voltage, four for current. Built-in memory allows users to collect and store data over an extended period.
2. The Role of Smart Meters in the Smart Grid
This is Chris Matt, Managing Editor - Print & E-Media with Maintenance Solutions magazine. Today's tip is the role of meters in the Smart Grid.
Today's smart meters are critical components in an effective energy-management and power-monitoring program. Many meters incorporate technology specifically designed to interface with the Smart Grid via an energy management system. Many facilities have installed meters on major switchboards or critical equipment and can use information the meters gather to determine when periods of peak demand are imminent or to monitor power quality. But to be able to truly impact demand, a valuable use of capital might be a more significant investment in smart metering.
For example, a facility that meters nearly every major piece of mechanical equipment and electrical feeder will have a great deal of information available when managers need to make decisions on load shedding. If a facility has agreements in place with the utility to reduce loads during periods of peak energy use, being able to closely match the load it sheds to utility requirements might lessen the impact of this load adjustment.
Using a control scheme that can shed the load at each metered point, as well as historical and trending data gathered via the meters over time, a manager can make intelligent, real-time decisions as to load shedding. At the same time, the experience gained during these periods will help a manager facilitate improvements related to energy efficiency: The systems and equipment that have the smallest impact on a facility in relation to the amounts of energy they use are prime targets for improved efficiency.
Intelligent monitoring points in a building management system are not always meters. Many buildings feature smart thermostats or smart appliances, which provide data into, and can be controlled by an energy-monitoring system.
One challenge managers face when multiplying the amount of power metering and monitoring points is an overload of information. Fortunately, a number of companies are developing software solutions that automate building energy control to assist managers. These systems reduce large amounts of data into easily understood graphical interfaces.
3. Power Management: Demand Response & The Grid
This is Chris Matt, Managing Editor of Print & E-Media with Maintenance Solutions magazine. Today's tip focuses on demand response and power management.
Most institutional and commercial facilities operate on flat rates from electric utilities. In most cases, utilities base these rates on calculations of the average cost of power delivered to customers. This method has worked for years, but a growing reliance on cooling systems has created a large demand on the electrical grid for reliable power at reasonable rates.
Now, utilities face the choice of buying power from other utilities at high, sometimes unstable rates or building expensive power-generation facilities to meet peak demands. Utilities can use several options to address this situation. They can conduct energy-conservation programs that encourage customers to use less power during peak times. They also can employ smart meters that allow users to track consumption and reduce the amount of energy used during peak-load times.
Another method is to develop demand-response, or peak-shaving, programs.
Some utilities' peak-shaving programs alert a facility when it should go off the grid and generate its own power. Facilities often use natural gas and diesel-powered generators in such situations. Some facilities can operate completely off the grid for a few hours or even several days. Such facilities benefit from lower rates because they meet monthly generating-testing requirements, and managers know the facilities can operate properly when grid power is not available.
In some cases, utilities have generation partner programs, in which the utility buys back the power that facilities generate via alternative sources. This usually is accomplished using two utility meters. One meter is the normal meter that reads the amount of power a facility buys from the utility. The second meter reads the amount of power the utility buys from the facility.
Control systems on the market can monitor the current price of power the utility charges and the price the utility pays for power. As a result, the facility control system either can use the available green power on site or sell it back to the utility.
4. UPS: A Maintenance Checklist
This is Chris Matt, Managing Editor of Print & E-Media with Maintenance Solutions magazine. Today's tip is a checklist for uninterruptible power supply (UPS) maintenance.
The lifespan of UPS batteries is typically three-five years, depending on conditions and maintenance. At that time, technicians must replace them to ensure the unit operates properly. Keeping tabs on indicators of problems can ensure uninterrupted service to the equipment and facility operations, and, in many cases, a healthier bottom line.
Fortunately, many newer UPS have advanced monitoring systems that provide system status for such items as system voltage, battery back-up time, and battery test schedule.
Many systems can remotely alert technicians if a problem occurs. This information can be especially helpful if technicians monitor the facility remotely. Technicians also must test physical equipment quarterly, semi-annually, or annually using a specific checklist of items to cover. The schedule should include:
• conducting visual inspections for wear and deterioration of battery and insulation components
• cleaning and vacuuming the enclosure
• monitoring the enclosure's temperature and humidity
• performing thermal heat scans, which can indicate hot spots that often are the first sign of component failure
• testing other electrical-system components, such as transfer switches, circuit breakers, and maintenance bypasses.
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