A site-specific, customized data center commissioning process lets trades and vendors do their jobs, with direction, oversight, management and documentation detailing demonstration of component, subsystem, and overall integrated system performance in accordance with owner requirements.
A high-level but site-specific commissioning plan should be developed and reviewed with stakeholders. The plan needs to summarize, in as plain English as possible, what will be tested, how it will be tested, when it will be tested, how performance will be documented, plus schedule dependencies, test equipment requirements, and participant responsibilities. Once the plan is approved, site-specific, step-by-step test procedures must be developed along with a timeline. It is important to break procedures down into individual one-action line items wherever possible.
Attempting to accomplish several things in one step encourages omissions and sequence errors. Procedures need to be developed to follow a logical sequence; however, at the same time, procedures must be flexible enough to allow workarounds and out-of-sequence tasks where there are no dependencies. This is necessary to keep the process moving when inevitable problems arise requiring troubleshooting and repair.
Participants need to be scheduled, including test technicians, trades, and vendors. Test equipment must be deployed to the site, entailing rental, transportation, and storage costs. Scheduling is a real challenge even when things go smoothly. When problems do arise you want to avoid having 10 technicians watching and waiting for one tech to get his gear working correctly — or sending everyone home for a day or a week when other tasks can be performed and progress can be made during the current mobilization. Sometimes out-of-sequence work performed to keep the process moving identifies additional problems requiring attention, avoiding an additional commissioning mobilization.
Managing onsite testing should begin each day with a safety meeting. Daily activities, progress, and issues are documented and transmitted. A commissioning punch list must be developed and driven towards resolution of all issues. Resolved items need to be included in the final report for future reference, because problems down the road are sometimes related to issues identified and thought to have been resolved during commissioning.
Next a final, comprehensive commissioning report needs to be developed, including documentation such as an executive summary, as-tested procedure with results, recorded test data, issues, resolutions, and recommendations. Although this is a proven, repeatable process, it needs to be customized per client requirements or in collaboration with other service providers.
Many commissioning efforts are not thorough, or emphasis is misplaced. Testing critical cooling, power and life-safety support systems should include normal operation as well as every alternate automatic and maintenance bypass mechanism. Failover systems need to be understood and validated at load levels ranging from very light load to full nameplate or design load. Equipment does not need to be destructively tested up to its breaking point. But it does need to be operated under test loads before it is supporting live equipment such that it is proven to operate correctly in all its intended modes. A commissioning team should maintain a roster of partners for areas where required expertise may not exist in-house, such as for control systems, circuit breaker injection, or central plant testing.
Often without proper commissioning a critical facility will operate effectively, for a period of time. But when a redundant function is required, or a failover system must perform, or when a component must be bypassed for maintenance, this is when inherent design, equipment, or installation problems can surface. Sometimes latent problems surface years later, well beyond warranties and payment withholdings.
“After the fact” or retro-commissioning of facilities under operation is sometimes performed to root out latent problems. The need for retro-commissioning is realized after a new or upgraded system is put into operation without proper commissioning, and problems surface afterwards. Simply getting design drawings updated following construction, to include as-built changes, is often overlooked without a proper commissioning process. Operators are often sent into the battle field unprepared, armed with far-from-comprehensive standard and emergency operating procedures. Critical facility operators all too frequently need to learn on the job without effective training.
A commissioning specialist should be able to manage the entire commissioning process or pitch in where needed, supplementing others. Test equipment, including load banks, power quality meters, infra-red thermal scan cameras, ground integrity testers and circuit breaker primary and secondary current injection test kits must be provided and operated. Trade labor needs to be directed.
