In addition to employing a generator, other best practices for improving power reliability should be considered. They include:
Automatic Transfer Switch — An Automatic Transfer Switch (or ATS) is used to transfer loads from one power source to another. The most typical application for this component is in emergency and life safety systems, where power will automatically transfer from utility power to generator power when an outage is detected.
UPS — An uninterruptible power source, or UPS, filters the electrical service to sensitive critical loads and can act as a "bridge" during the brief time between failure of the utility power and start-up of the backup generator system. UPS systems can provide battery backup for a short duration — typically 10 to 15 minutes. Made up of batteries that need to be replaced about every five years, the UPS system life expectancy is approximately 10 to 15 years.
Surge Protection Devices — Surge protection devices protect the building's electrical distribution system from voltage spikes often caused by lightning. These are relatively inexpensive devices to install, but several precautions must be followed to ensure they are installed correctly.
Redundant Distribution — An electrical distribution system can be enhanced by providing multiple (or redundant) paths between the available electrical service and the critical loads. This can help reduce the impact of a service or equipment failure. It can also provide a means to take offline part of the distribution system for maintenance without interrupting service to the loads. There are many ways a redundant distribution system can be installed, depending on the associated risks and the impact of an outage on the building occupants.
Secondary (Alternate) Utility Service — Ideally fed from a utility grid or substation that is different from that used for the building's primary service, a second electrical utility feed can provide service redundancy.
Two other best practices are also important for facility managers who are working to improve power reliability. One is an arc flash hazard analysis. An arc flash study will analyze the building's electrical system to outline necessary safety precautions and establish systems to improve equipment up-time. The study also defines the potential hazard levels in the event of an electrical fault and details what type of clothing operators need to wear when visually inspecting or performing maintenance on equipment. The study will also help ensure that the electrical systems are coordinated to minimize the impact of equipment failure as well as provide proper arc flash labeling of electrical equipment, as required by OSHA.
Preventive maintenance is another best practice for power reliability. Instead of waiting for equipment to fail, regularly scheduled maintenance of a building's electrical system can reduce the occurrence for emergency repair and equipment replacement. This can include the infrared scanning of equipment, regular exercising of overcurrent protective devices, and load bank testing.
Austin Bredow, PE, LEED AP, vice president; Joe DuTemple, RCDD, vice president; and Larry Dykstra, PE and LEED AP, all work at Environmental Systems Design, Inc., Chicago.
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Others Ways for Improving Power Reliability Include ATS, UPS
