Whenever critical electrical systems are deployed, load bank testing ensures the reliability of these systems. Basically, a load bank supplies an artificial load to a variety of equipment, including generators, uninterruptible power supply (UPS) equipment, power distribution units (PDUs), battery backups and other electrical and mechanical systems.
Load bank testing solutions come in a wide range of configurations and capacities. The load bank used will depend on the application and specific site requirements.
Why should you use load bank testing? Some important reasons include the following:
- The main goal of load bank testing is to uncover problems in a controlled situation rather than during an actual power failure. Load bank testing should be conducted during initial system installations, but also as part of a regular maintenance program.
- Load bank testing is the only way to verify a backup power system will operate during an outage. Backup systems such as generators and UPS equipment may perform adequately under light loads. However, without regular testing, they may fail to deliver a full power load. Load bank testing ensures your backup systems are up to the task.
- When operating under light loads for extended periods, diesel generators may experience a condition called “wet stacking.” Wet stacking happens when carbon or unburned fuel oil accumulates in the exhaust system. This accumulation reduces output and may permanently damage the generator. Wet stacking can be corrected simply by running the generator engine under a sufficient load for a few hours.
- Standards compliance may dictate load bank testing. For example, the National Fire Protection Association (NFPA) “Standard for Emergency and Standby Power Systems” provides requirements for initial commissioning of an emergency power supply, as well as ongoing testing. Other standards organizations imposing mandates for load testing include the ANSI/NETA Standard for Maintenance Testing Specifications for Electrical Power Equipment and Systems, and the Joint Commission on Accreditation of Healthcare Organizations.
- During data center commissioning, load banks can be used to test mechanical cooling systems by simulating the heat load of critical electrical systems. Water-cooled load banks also test chiller plants to ensure they meet their design ratings.
- Chiller plant testing is a part of an integrated system test where all systems are tested as a whole – as they are installed. This testing will sometimes uncover problems that do not get detected in component level testing and factory testing.
How are load banks physically configured? Three main types of physical mounting configurations exist:
- Portable – These load banks range in size from a small suitcase to a large trailer-mounted unit. Because of their flexibility, portable units are most commonly deployed.
- Permanent – Permanent load banks are geared toward larger installations with multiple generators or UPS systems. They provide testing during initial commissioning, as well as on an ongoing basis.Permanent load banks can also be radiator-mounted. Convenient and economical, radiator-mounted load banks are commonly used to test a single generator. Instead of relying on an internal cooling fan, these load banks use the generator’s cooling system fan to provide cooling.
- Rack-Mounted – A temporary, portable load bank, rack-mounted units are typically used during data center commissioning. They accurately simulate the electrical and heat load of critical computer systems before the computers are actually installed. Rack-mounted load banks are often the only way to validate the performance of a data center’s cooling systems.
With the increasing demand for reliable electrical systems, the need for load bank testing will continue to rise. Load bank testing helps ensure your systems remain available and conform to requirements. By carefully specifying, installing and operating load banks, you can improve the reliability of your electrical and mechanical systems. And a more reliable operation minimizes the costs associated with unplanned downtime.
Comrent’s team of experts is ready to help ensure your system is successfully commissioned. We are offering a complimentary consultation to review your project and propose the right load bank solution for your application. Contact us today.