Consulting-Specifying Engineer - May 2008 - (Page 50) Those who seek out standby and prime power solutions rely on partners who are up to speed. Who stand ready with ideas. Who are, in a word, “on.” Kohler® is that partner, on because the people behind the name are on. Always. And whether we’re providing a turnkey system to protect your most critical applications or thinking through an eminently effective solution to a unique challenge, you’ll know the power will be on, guaranteed. Come to Kohler and tell us what you need. We’ll bring it. On. distribution and environmental control (HVAC) within the critical spaces. Lifesafety systems, including fire detection, suppression, and alarm systems, also are critical, and so are building automation systems. The “can” systems are the ancillary systems, such as task lighting. Regarding the components, each component within a system has a specific purpose and operation to fulfill that purpose. The extent to which that component is tested to ensure it operates correctly needs to be established based upon its impact on system performance. For example, if a space temperature needs to be controlled within 1 F, the appropriate sensor should be tested against that criterion, in its installed configuration, within the actual operating temperature range. Regarding systems and integrated systems, they are designed to operate according to a specified sequence of operation. The sequence is a combined group of operational criteria to be maintained and system responses to data inputs to achieve those criteria. The testing of a critical system must test all the designed sequences, in all component configurations, in a real-world environment. If a chiller plant has three chillers and is designed to operate with all three in a lead/lag redundant configuration, the load-test needs to stage up to three chillers and all the way back down to one chiller. Also, this needs to be done with all three lead-chiller configurations. Furthermore, the coordination of pump start/stop, isolation valve open/close, and chiller start/stop/status needs to be tested to ensure it works in all configurations. These may seem redundant or over the top, but these scenarios will very likely occur in real life, and it’s impossible to tell if the systems will respond adequately unless they are tested. Speaking of real life, systems operate in simultaneously, so integrated systems testing should duplicate real life operation of the facility as closely as possible. This will require simulating data center operations to check integrated HVAC and electrical performance. To mock-up data center operations, smaller suitcase load banks (30-kVa) can be spread evenly over the raised floor area to mimic the computer load. This enables integrated systems testing to ensure computer room air-conditioning units are providing uniform heat removal and staging properly. Infrared scan can be performed to identify hot spots. It is also important to research to local utility’s substation breaker reclosure scheme in order to develop real life “pull the plug” power outage testing scenarios. Often overlooked is a short time outage when a substation breaker recloses after clearing a fault. Phases/activities As defined ASHRAE Guideline 0 the Cx process consists of multiple phases, each having prescribed tasks. The major tasks within each phase are listed below, with examples of the types of issues requiring significant definition and detail. Pre-design phase: The pre-design phase lays the foundation for the Cx of the project. It is in this phase that the owner’s project requirements (OPR) is developed and the Cx scope and plan are determined. It is in this phase that the “depth and rigor” of the testing must be determined. Key steps in this phase include: • Develop the OPR • Determine the scope and budget of the Cx process • Develop the initial commissioning plan (CP). The purpose of Cx is to ensure the delivered facility meets the OPR. For data centers, the OPR will include the required the Tier level, user requirements, environmental and safety requirements, redundancy levels, system expectations, operating efficiencies, and other owner expectations for the facility. The CxA must work with the owner to identify the depth of testing, which will be the basis for the Cx scope. The CxA will develop a CP based on the Cx scope and OPR. The plan will identify all steps in the process, detailing the performance, documentation, and acceptance criteria. A CP for critical facilities will necessarily be much more detailed than that of KohlerPowerSystems.com Input #224 at csemag.com/quickResponse http://KohlerPowerSystems.com http://KohlerPowerSystems.com http://csemag.com/quickResponse
For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.