Ensuring the Lights Stay On

In officially commissioning buildings for the past 10 years, it's been our experience that given the myriad of building systems in line for such testing, the most critical task is ensuring the safety and reliability of backup power systems. As senior vice president and national commissioning program leader for Carter & Burgess, Inc.


In officially commissioning buildings for the past 10 years, it's been our experience that given the myriad of building systems in line for such testing, the most critical task is ensuring the safety and reliability of backup power systems.

As senior vice president and national commissioning program leader for Carter & Burgess, Inc., my Chicago-based team and I have gained considerable experience from construction projects across the nation and have come to understand the impact and consequences of power disruptions.

When disruptions occur, negative experiences have prompted positive actions. There have been many infamous, highly publicized emergency power system failures where sequences of operations didn't work—whatever happened wasn't suppose to happen.

Our job is to verify in detail that when an owner occupies a building, all of the systems perform to original design criteria.

Developed initially to verify the performance of HVAC systems, the commissioning process followed by Carter & Burgess is patterned on an ASHRAE guideline and other industry-defined standards.

We are constantly assessing the construction industry's potential for commissioning and retro-commissioning assignments and are finding a healthy market for backup power systems at hospitals, university-research facilities, mission-critical installations and airports—in other words, facilities where electrical power loss can cost lives and millions of dollars.

It may not be happening with a lot of fanfare, but industries are now backing up their own systems. The combined effect of the 9/11 tragedy and last year's electrical power blackout in the Northeast have made us all painfully aware of how dependent our lives and business operations are on electrical power.

Emergency power systems are most often incorporated into projects as a code mandate and have the capacity to handle fire and life-safety loads, including fire pumps, critical lighting and fire-fighting elevators, for example. The capacity is often increased to handle additional mission-critical loads.

In health-care facilities, this could include operating-room utilities. In research laboratory buildings, the critical loads would include fume-hood exhaust and animal-holding systems, because long-term experiments could be seriously compromised, and the surrounding environment endangered, in the event of power loss. Corporations rely on data collection and processing, so data center installations are typically supported by both emergency power and uninterruptible power supply (UPS) systems. Radio and TV broadcast facilities similarly rely on emergency power systems for continuous operations.

The objectives of commissioning emergency power systems go far beyond establishing the highest possible level of confidence that the generators will start. The functional test procedures, which are a critical component of the commissioning process, verify that all system interfaces are performed as designed and that the various sequences of operation are all in place. Further, detailed operator training is provided to raise the level of understanding and ability of operators to handle routine and, most importantly, unexpected operating issues. Therefore, equipment failures will be minimized and in the event that a component does fail, the operators are well trained to handle the situation. Lastly, the commissioning process results in collection and organization of recorded documentation, which is very important to ongoing, effective troubleshooting of operational issues.

Commissioning has become more prevalent as systems have increased in complexity and required reliability. Carter & Burgess serves as a commissioning authority on numerous projects, ensuring from the design phase that controls, switches, valves, filters, generators and other components are accessible and not in conflict with other equipment.

During the design phase, the commissioning team develops a process plan, collaborates on development of owner project requirements and drafts commissioning specifications, which are incorporated into the contract documents. Design reviews are focused on the operational and maintenance issues of system installation and are intended to assist the designers with another perspective on overall system performance. Commissioning engineers attend pre-bid meetings with potential contractors and explain contractor responsibilities and the level of rigor of the commissioning process during the construction phase so there are no surprises later.

As construction progresses, the commissioning team compiles manuals on the operation of each system and supervises and schedules operator training sessions that are recorded and otherwise documented. Testing of each component and system, through all sequences of operation, is carried out according to detailed functional test procedures. The functional testing results is a pass-or-fail determination, which is documented and communicated to all members of the project team. A fail result will require corrective action on the part of the contractor, and retesting will take place until the functional testing results in a pass result.

The owner will be given a level of comfort in knowing that the emergency power system performs in accordance with project requirements and that operators are fully trained and ready to assume permanent operation of systems. The commissioning team also submits a warranties matrix that identifies the expiration dates of warranties and the owners' responsibilities for keeping logs of warranty claims and performing routine maintenance. Through this process, the commissioning team acts as a troubleshooter to bring to closure remaining issues related to the punch list.

Carter & Burgess typically commissions backup power systems as a part of larger projects. And the research shows that thus far only 10% of the commercial projects being constructed across the United States are commissioned. One hypothetical scenario developed from case studies presented at the annual National Conference On Building Commissioning suggests that an owner could save $4 in operating and maintenance expenses over the first five years of permanent operation of systems for each $1 invested in direct commissioning cost.

That scenario suggests a tremendous untapped market for commissioning in general, and emergency power systems are prime candidates for this process because of their critical operating requirements. The majority, by far, of the larger, complicated projects typically would have emergency power systems associated with them.

Additionally, the scope for commissioning has expanded dramatically in the past few years to evolve beyond buildings. Among the most promising areas for commissioning and re-commissioning existing systems is transportation.

In every case, the focus is on commissionability of systems: in other words, how we are going to be able to operate them, and how we can verify that they perform to meet owner project requirements. We're looking at this from the perspective of the building operator rather than the designer or contractor.

A case study

Commissioning the new campus of RadioShack Corporation—spread across 38 acres in downtown Fort Worth, on a river bank formerly occupied by the old Tandy Center parking lot and a public housing project—will be Carter & Burgess' biggest backup power system challenge to date.

The RadioShack project, which covers three, six-story buildings offering 900,000 sq. ft. of office space, as well as a centrally located "commons" facility, was launched in 2003, and construction is expected to be completed by year's end, with occupancy completed by the first quarter of 2005. Built in conjunction with a Dallas-based team that includes project manager The Staubach Company, designer HKS and contractor Beck Construction, it will include additional areas for meeting, dining and athletics. A vital component is emergency backup power to safeguard against the loss of a significant amount of data streaming into the company's computers from nearly 5,100 company-owned retail stores in the continental U. S., Hawaii, Puerto Rico and the Virgin Islands. The 4.5-MW capacity of emergency generators will handle all fire/life-safety and data center loads, with the latter also supported by an uninterruptible power system.

The commissioning process is also vital to the nation's airports, where an August 2003 failure in the vast grid feeding power to the Northeastern U. S. shut down 21 power plants in just three minutes and left major portions of New York City, Cleveland, Detroit, Toronto and Ottawa in the dark. Air traffic controllers halted traffic at New York's JFK and other airports across the region. It took rescue workers nearly three hours to evacuate passengers stranded in the city's subways.

Last summer's blackout has really caused entities such as airports to consider how much backup power they have. Commissioning can be a valuable service in verifying the reliability and operating performance of emergency power systems so that the "lights stay on," even in the face of extended power failures.

Don't Oversize Data Centers

Data centers and network rooms are routinely oversized to three times their required capacity. Oversizing drives excessive capital and maintenance expenses, which are a substantial fraction of the overall life-cycle cost. Most of this excess cost can be recovered by implementing a method and architecture that can adapt to changing requirements in a cost-effective manner while at the same time providing high availability.

As noted in the figure, the capacity of the power and cooling equipment installed is equal to the room capacity. In other words the system is completely built-out from the beginning. The plan is that the expected load of the data center or network room load will start at 30% and ramp up to a final expected load value. However, the actual start-up load is typically lower than the expected start-up load, and it ramps up to an ultimate actual load, which is considerably less than the installed capacity (note that the nameplate power capacity of the actual equipment installed may be larger than the installed capacity due to redundancy or user-desired derating margins).

One possible solution is to consider a scalable, packaged modular approach. The data center or network room power infrastructure would be provided in pre-engineered modular building blocks. The components could be wheeled in though common doorways and passenger elevators and plugged in without the need for performing wiring operations on live circuits. The system would be capable of operating in N, N+1 or 2N configurations without modification. More imporantly, special site preparation such as raised floors would be eliminated, as would installation work such as wiring, drilling and cutting.

Furthermore, one-time engineering associated with the data center and network room design would be greatly reduced or eliminated; special permitting or regulatory procedures would not be required in order to increase capacity; the equipment cost of the modular power system would be the same or less than the cost of the traditional centralized system; and the maintenance cost of the modular power system would be the same or less than the cost of the traditional centralized system.

For a white paper on data center oversizing and solutions from American Power Conversion, click the green Electrical button at

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