Elements of Critical Power Systems and Their Management

Credit: ASCO
The control panel shows the types of information an operator needs to know.

Editor’s note: This article first appeared in the January/February 2010 issue of Business Energy.

A single power interruption can cripple a healthy company, says Bhavesh Patel, director of marketing of Emerson’s ASCO Power business. “Not having adequate onsite power can be the ‘Achilles heel’ of a business, but the controls for operating, monitoring, diagnosing, and producing a variety of mandatory reports on these power systems and the power distribution systems they interact with are not keeping pace,” he says.

According to a survey taken, 76% of facilities executives reported that their facilities do not have a unified system. “Typically, they have a system provided by most manufacturers from whom they buy equipment, but the process of monitoring, controlling, reporting, and power quality analytics can be disjointed,” says Patel. This interferes with best practices.

“Critical power management systems are no longer just a ‘want-to-have.’ They’re ‘must haves’ because they’re crucial to increasing facility reliability, compliance, and efficiency, and supporting today’s various mission-critical processes,” adds Patel.

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Data Centers
The data center is the backbone of business and requires innovative, mission-critical power and thermal management solutions that drive efficiency, quickly scale to meet needs, and ensure optimization of IT assets, points out Philip Fischer, global data center segment manager for Eaton. “These solutions need to be easy to deploy and resilient enough to accommodate reduced facility infrastructure redundancies, all while assuring power quality and reliability,” he says.

For IT and facilities managers, server virtualization is a “hot topic” as it brings about both challenges and opportunities. “Server virtualization empowers businesses to lower hardware spending, simplify administration, and boost availability,” he says. “It also makes preventing downtime during utility failures dramatically easier, provided your data center is equipped with the proper power management software. Additionally, it adds new complexities to the demands of avoiding data loss during electrical outages when shutting down servers is unavoidable.”

The latest power management solutions position companies to take full advantage of server virtualization’s rewards while mitigating its risks by enabling data center managers to migrate virtual machines onto unaffected host devices automatically during utility service interruptions, says Fischer. “They also equip IT and facility managers to shut down physical servers gracefully when such measures are unavoidable.”

When it comes to IT assets, no company can afford to be unprotected from power issues, Fischer points out. “Even short outages can be trouble,” he explains. “Losing power for as little as a quarter-second can trigger events that may keep IT equipment unavailable for anywhere from 15 minutes, to many hours.”

And, downtime is costly. “Some experts believe the US economy loses between $200 billion and $570 billion a year, due to power outages and other disturbances,” says Fischer.

Utility power isn’t clean. “By law, electrical power can vary widely enough to cause significant problems for IT equipment,” he says. “According to current US standards, for example, voltage can legally vary from 5.7%, to 8.3% under absolute specifications. That means that what utility services promising 208-phase voltage actually deliver can range from 191 to 220 volts.”

Nor is utility power always reliable, adds Fischer. “In the US, it’s only 99.9% reliable, which translates into a likely nine hours of utility outages every year,” he says.

Problems and risks are intensifying. “Today’s storage systems, servers, and network devices use components so miniaturized that they falter and fail under power conditions earlier-generation equipment easily withstood,” he says. “Generators and surge suppressors aren’t enough. Generators can keep systems operational during a utility outage, but they take time to start up and provide no protection from power spikes and other electrical disturbances. Surge suppressors help with power spikes but not with issues like power loss, under-voltage, and brownout conditions.”

Fischer points out that at one time, IT played a supporting role in an enterprise. “These days, it’s absolutely central to how most companies compete and win,” he says. “When IT systems are down, core business processes quickly come to a standstill.”

While “availability is everything,” power costs must be managed, Fischer states. “The cost of power and cooling has spiraled out of control in recent years. Data center managers are typically held responsible for achieving high availability, while simultaneously reducing power costs. Highly efficient UPS systems can help with this goal, and products are available today that were not an option even a few years ago.”

Eaton delivers end-to-end data center solutions designed to maximize return on investment from incoming utility to rack outlet, says Fischer. Eaton’s Intelligent Power Software Suite is designed to supply the tools needed to manage power devices in a physical or virtual environment.

“The software ensures system uptime and data integrity by allowing data center managers to remotely monitor, manage, and control the devices on their network,” says Fischer. “Eaton’s Intelligent Power Manager software is designed to automatically synchronize virtual machines and initiate recovery failover to avoid data loss and reduce downtime during a power event. The software also is engineered to identify a power event immediately, initiating a backup site and triggering disaster recovery failover and planned migration processes.”

Today’s data center and IT managers are striving to balance technological innovation with functionality and cost, Fischer points out. Eaton’s ePDU G3 (Enclosed Power Distribution Unit) combines these capabilities into one solutions portfolio, featuring a new IEC outlet grip designed to eliminate the common, and often costly, problem of plugs falling out of IEC outlets due to bumps or vibrations, he says.

“The grip can help eliminate additional expenses related to cable trays or special power cords, which can increase rack PDU purchase costs up to 50%,” says Fischer. “The grip feature pairs with energy-efficient technology aimed at reducing cooling costs and extending the life of hardware for added reliability. ePDU G3’s high-operating temperature-up to 140 degrees Fahrenheit-also helps meet new temperature guidelines for cooling set by ASHRAE.”

The Eaton 93PM UPS three-phase system is engineered to low total cost of ownership. The 93PM is designed with flexible deployment options that support integrated thermal management solutions, a compact footprint, efficiency up to 99% and simplified energy management features.

“Efficiency is profoundly influenced by UPS design or operating mode,” points out Fischer. “The 93PM offers multi-mode operation, often called ‘eco-mode’ or ‘high-efficiency mode.’ It operates in high-efficiency mode unless power conditions warrant a switch to the higher protective level of double-conversion mode.

“This new multi-mode technology provides exactly the level of power protection needed under the conditions of the moment,” he continues. “The results can be dramatic as even small increases in UPS efficiency can quickly translate into tens of thousands of dollars.”

Case in point: assuming a utility rate of 10 cents per kilowatt-hour, a 60-kW N+1 redundant configuration would save more than $30,000 in five years, with the savings compounded with data center size.

Eaton’s integrated power management solutions are optimized to work together. “Eaton’s Intelligent Power software, for example, works in conjunction with products such as ePDU G3 and the 93PM UPS to provide capabilities previously not available,” says Fischer. “Eaton’s latest version of Intelligent Power software, version 1.43, is also preconfigured to operate with VMware vCenter Site Recovery Manager, eliminating the need to download additional modules for deployment.

“Eaton’s newest enhancement is the latest improvement upon the software’s existing VMware integration, which enables IT personnel to view, monitor, and administer physical and virtual servers, in addition to UPSs, enclosure power distribution units (ePDUs) and other power devices, through the VMware vSphere 5.5 virtualization platform.”

Using vSphere APIs, Eaton’s Intelligent Power software integrates with both the new version and legacy vSphere’s Web client, Fischer says. The integration allows discovery of ESXi hosts, as well as NetApp and EMC storage devices and Cisco’s UCS server.

“Connecting these devices to Eaton’s Intelligent Power software is intuitive, menu-driven, and accomplished with three to four clicks,” says Fischer. “Configuration of Business Continuity policies upon power or environment events is accomplished via a simple user interface. Intelligent Power software policies can combine both ESXi actions and power capping through Cisco UCS manager.”

Be it a data center, hospital, or bank, facilities are dependent upon power reliability, and the industry is responding in kind. Telx provides services in data centers, colocation, data center interconnection, and cloud and connectivity services. The company has 21 data centers in 13 markets throughout the United States.

Power reliability is the heartbeat of such a business. Richard Coleman, director of construction at Telx, is tasked with ensuring that reliability through the equipment choices he makes.

Telx has been using Emerson Network Power’s ASCO Power Technologies’ automatic transfer switches, as well as equipment from Russelectric, 3-MW diesel Caterpillar generators and Cummins engines. “We’ve been primarily using ASCO equipment based on lead times from their factory and the reliability of the product,” notes Coleman. “Backup power is the key to our success, so it’s got to be reliable. This fits into our business plan for New Jersey.”

In addition to reliability, Coleman seeks price and service in equipment choices as well as alarm conditions on the equipment, and a good response time in the event that maintenance needs to be performed.

“That response time is one of the key indicators of going with a company or not,” he adds. “Certain markets have certain levels of support. In Chicago, Cummins may be a better manufacturer for us, whereas in the Tri-State area, there’s more competition.”

With respect to the ASCO Series 7000 automatic transfer switches, Telx favors switches with bypass-isolation configurations to allow testing of the switch without interrupting power to the load. “We use a bypass isolation type in the event we don’t have a footprint to install two devices, because we like that redundancy,” says Coleman. “One is being maintained, the other can support the customer load.”

Telx has a certified Tier 3 facility in New Jersey that the Uptime Institute commissioned to be sure it meets concurrently maintainable standards. “It’s all about tests from the generator point because they look at that as our utility,” points out Coleman. “We commissioned the infrastructure when we installed it on day one. Then, we hand it off to our facilities operations team who maintains the equipment according to manufacturers’ recommendations.” Sometimes Telx will purchase preventative maintenance packages with the equipment so as to save on maintenance costs down the road, he says.

Superstorm Sandy put the equipment to a rugged test in Manhattan, where Telx was able to run “that lengthy duration of backup power supported by CAT engines and ASCO equipment, which performed flawlessly,” says Coleman. “We ran this equipment for a week straight, so we didn’t drop any customer loads. That proved the reliability of the equipment. If it’s maintained properly, it’s there when you need it. We needed it longer than expected.”

Management of Critical Power
ASCO Power supports ongoing development in a range of power switching and controls technologies. One of the most crucial areas of development is critical power management systems (CPMS), Patel says. A CPMS monitors and controls emergency generator sets, circuit breakers, transfer switches, bus bar meters, paralleling control switchgear, and other emergency power system equipment.

It facilitates onsite power system testing, load management and load bus optimization, reporting, and diagnostics. The system also monitors normal and emergency voltages and frequencies, indicates transfer switch position, current, power, and power factor, and displays transfer switch event logs, settings, ratings, and identification.

Several key CPMS technologies and capabilities help increase onsite power reliability and efficiency, Patel points out. They include dynamic electrical one-lines, automated testing, reporting and scheduling, and power quality analytics. Digital electrical one-line diagrams dynamically visualize the comprehensive electrical connections between critical power equipment.

A range of automated capabilities help facilities managers optimize onsite power assets. Automated testing helps satisfy requirements for generator load testing. Automated reporting produces test, outage, alarm, and energy reports.

Monitoring and reporting capabilities help fulfill requirements to track power load capacity and demand. Colocation data centers report on any downtime as part of a service level agreement. Automated scheduling helps ensure performance of required emergency power supply system maintenance.

Power-quality analytics help facilities managers assess power health and reliability by providing automated Information Technology Industry Council plots and a dashboard. Power-quality analytics can identify where a failure could have occurred and in some cases may help avert a failure by detecting problems, Patel points out.

Post-event troubleshooting identifies exactly what started the events, their precise sequence and duration within a very small time frame, often in microseconds, he says. Power quality analytics also are used for trending and predicting capacity requirements.

Critical power management systems operate at extremely high speeds to gather and share voluminous amounts of data from a range of equipment, including emergency generator sets, circuit breakers, transfer switches, bus bar meters, paralleling control switchgear, and other emergency power system devices, often from multiple manufacturers, Patel says.

“This data stream would overwhelm most building management systems or data center information management systems, so power control systems export only crucial operational data to them, such as automatic alerts on system operation via e-mail, pager, or selected system alarms,” he adds.

Nemours, a non-profit children’s health system, opened a new $397 million hospital in Orlando, FL, in October 2012. The state-of-the-art, 630,000-square-foot medical hospital has 95 private rooms, a full-service pediatric emergency department, and a 60-acre, fully integrated health campus with research and education facilities.

As is the case with all critical care facilities, Nemours is required by local, state, and federal codes to have emergency standby power systems that can be online within seconds of a utility outage. The preference is to meet not only current power generation needs, but also plan for future growth that may require additional load management.

To that end, the hospital installed a new central power plant equipped with four 2,250-kW MTU Onsite Energy generator sets with paralleling switchgear. The system offers an 85% load factor.

“Generator sets are vital to hospitals today,” notes Nelson Roque, director of facilities and construction at Nemours. “They keep critical systems such as resuscitation and life-saving machines online, but it’s not only those systems that depend on generator sets. Everything runs on electricity, and without it, we really couldn’t function as a hospital.”

In the more than two years that the MTU Onsite Energy generator sets have been installed, they’ve proven their capability in handling consistent demand for critical power in an area of the country beset by heat and hurricanes.

Roque worked with Florida Detroit Diesel-Allison (FDDA), the local MTU Onsite Energy distributor, to equip Nemours with an emergency power system capable of withstanding the elements. The generator sets were installed on the hospital’s second floor to decrease the potential for flood damage and ensure a reliable power supply for seven days.

Nemours tests its generator sets and switchgear monthly by triggering different areas of the hospital to simulate a power interruption. “We’re confident that if something should happen, the generator sets will work perfectly just like they do in testing,” says Roque.

Nemours’ leadership team was impressed by the MTU Onsite Energy power system installed at the Halifax Health Medical Center in Daytona Beach in 2009, which the Florida Agency for Health Care Administration cited as an example of “the way it should be done.”

MTU Onsite Energy offers both diesel and gas generators, also designed for Combined Heating and Power applications. “That can go beyond the standard generator set and give the customer another solution for cost savings or for payback to be more energy-efficient and have a greener solution than just diesel power,” says Kevin McKinney, senior manager of sales support, North America/Latin America at MTU Onsite Energy. The Series 4000 engine platform will meet EPA Tier 4 emissions standards, he adds.

MTU Onsite Energy offers standby, prime, continuous, and data center power-rated units with various load factors to serve different applications, McKinney says.

At 85 years old, Elmhurst Memorial Hospital in Elmhurst, IL, was having a lot of issues. “We had issues with losing power and because of that, many of our critical areas had a problem because of the 10 seconds that it took the generators to come up on line and pick up the power,” says Gene Farb, director of facilities management.

When a new hospital was built in 2011, facilities managers saw to it that power would be more reliable. The essential power system for the new Elmhurst Hospital in Elmhurst, consists of four 2250-kW, medium-voltage Caterpillar generators and associated paralleling switchgear. Closed-transition transfer switches from Russelectric give the hospital more capability for testing and synchronizing with the utility, notes Greg Liedtka, chief engineer.

The generators are sized to power the entire campus during a utility outage-including the new hospital, the existing Center for Health building and the two proposed medical office buildings-as if normal utility power was available.

The electrical switchgear was designed to allow the hospital to “drop off” of the utility grid and reconnect to the grid without the occupants of the building knowing that a transfer had been made.

The hospital’s critical power branch is fed from two 1,300-kVA battery-free rotary Uninterruptible Power Systems (UPS) from Piller. These two systems were designed into the hospital’s distribution system to provide conditioned “clean” uninterrupted power and continue providing power during an outage while the emergency generators are starting and coming online.

The battery-free UPS was chosen as a sustainable design feature to provide continuous power without having to deal with acid batteries that must be replaced frequently. Loads that will be served from the UPS systems include imaging equipment, operating rooms, C-section, laboratories, pharmacy, IT closets, and other selected receptacle loads throughout the building.

In choosing the appropriate equipment, concerns such as local support were important, notes Liedtka. “Caterpillar is a local company and has a great product,” he says.

Electrical consultants made recommendations on the other components of the system. Piller was chosen because of the large capacity unit it offers. The main purpose for the complexity of the system is continuity, Liedtka points out.

“Elmhurst has experienced quite a few power bumps,” he says. “We have a lot of overhead lines, and the old town has a lot of trees. It’s also from a patient safety and comfort standpoint to have power that doesn’t drop out in the middle of surgery as the doctor’s operating on you.

“We have two main utility feeder lines, and, in doing some of the upgrades, we’ve had to come offline with one of those lines,” he continues. “We’ve been able to do it seamlessly without anybody in the hospital seeing it, so I think that’s part of the reason for why we made the system as well as we did.”

Four days before patients were moved from the old hospital three miles away to the new facility, there had been a major power outage in Elmhurst. “For two days, the old hospital was warm, there was no air, it was sweaty and patients were discharged early,” says Liedtka.

The new campus was fully backed up with three generators. “You walked in the building as if nothing had happened,” he says. “There were lights, cooling, air-everything. We had a test of the system before we moved in. We’ve had minor outages and some bumps, but nothing for any serious length of time.”

Now with four generators, one can be taken offline for maintenance without affecting the coverage in the building, says Liedtka. “We have maintenance programs set up with Caterpillar and Russelectric to perform maintenance and testing, and we have maintenance on the flywheel as well,” he says. “They come in twice a year, but there aren’t numerous batteries to deal with.”

The benefit of the system is that because it was a new project, “we had the opportunity of designing it just the way we wanted the place to work with state-of-the-art equipment,” says Farb. “It’s so much different than if you do a remodeling of an existing hospital.”

There has been a learning curve with the system, notes Liedtka. “Nobody had worked on systems like that here,” he says. “The challenge is learning the system, what you can do, how you can do it, when you can do it. It’s also a challenge as far as our regulators are concerned: the system is not like anything they’ve seen before, so trying to explain to them how it works and get them to understand it is a little different, too.”

Farb advises facilities operators to go with a UPS system similar to that in his hospital. “On an existing hospital, it could be cost-prohibitive, so I’m not sure it’s possible,” he says. “For any new construction of a hospital, our advice would be to go with this type of UPS backup system.”

A major benefit derived by all of the modalities such as MRIs and other imaging services is that they will not experience a 10-second delay, “so they don’t have to start the procedures again, which happened with the old hospital,” notes Farb. “It’s difficult to spend the money upfront, but you’re better off spending the money upfront and getting more than you need at the time because hospitals never stand still. There’s always expansion. It’s about the patients, not just about the money. If patients are turned away because you’ve shortchanged what you’re planning on, then you’re not meeting their needs.”

Piller’s UNIBLOCK rotary UPS system combines the motor and generator components on a vertical arrangement to provide a compact, high-density power source, says Victor Muscia, regional sales manager, Midwest, for Piller USA. Piller system also provides a short-term energy source between when the utility goes out and the start of the backup generation of a diesel generator, fuel cell, or a gas turbine, says Muscia. The Powebridge Flywheel is a battery-free alternative for Direct Current (DC) energy supply in a Piller UPS system. It is a vertically mounted flywheel and generator designed to operate within a speed range of 3,600 to 1,500 rpm.

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The unit can deliver eight seconds of ride-through at 2.4-MW load, and proportionately longer ride-through at lesser loads. One can choose 6-MW, 16.5-MW, and 21-MW available energy storage. No air conditioning is required. The system offers defined, predictable charging states and can be set up as parallel units.

“If you had a load of about 1,000 kilowatts, and you used the large 21-megawatt flywheel, you can run almost 20 seconds before you have to have your long-term energy source come online,” says Muscia. “You can fully unload that device and recharge it in under a minute. It’s a very fast recharge, but also gives a burst of energy very quickly.

“It can take energy in as fast as it can take energy out,” he adds. “That makes it very good for stabilization and microgrids.”

Muscia is seeing a trend toward people wanting more onsite power generation and perhaps selling power back to the utility or disconnecting from the grid altogether, but wanting to have a stable system to accommodate large capacity. “This is basically an energy ‘sponge’, putting energy out when you squeeze it and soaking it back in when you need it to,” he says. “It keeps the systems very stable.” BE_bug_web


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