Power Quality & Related Problems
It has been estimated that power related problems cost U.S. companies in excess of 26 billion dollars annually. Considerable cost savings can be realized by being proactive in high tech environments. This is especially true when the electrical system feeds mixed loads such as personal computers, work stations, lighting, HVAC, etc.
Power Quality Solutions and Piper Electric Co, Inc. are committed to providing the best in commercial and industrial power management services to their customers. As part of that commitment, we strongly suggest that the following areas of concern be addressed in our customer’s electrical systems.
Power conditioning is a term that is widely, and in many instances, misleadingly used by sales people to describe various types of equipment. True power quality is only achieved through careful planning and understanding of the overall facility electrical system and the equipment that it feeds. Installing a “power conditioner” cannot solve transients, sags, swells, outages, harmonic distortion, ground noise, poor maintenance, and equipment mis-application or installation.
A multilevel-networked surge protection system should be installed in every modern facility. Typically, a suitable device should be installed at the main switchgear, each power panel throughout the building and on incoming communication lines. Surge protection will not protect from a direct lightning strike, but will provide general protection from utility & facility indirect surges. Home owners should consider installing surge protection to protect their electronic appliances & equipment.
Harmonic distortion occurs when significant portions of the electrical load in the facility are electronic power supplies, such as those found in computers or variable frequency drives. The non-linear way that this equipment utilizes power is incompatible with traditional sinusoidal or linear power system. Harmonic currents cause extra heating, potentially overloading electrical system components such as transformers, capacitors, motors, generators, and conductors. They also flow through the system impedance and cause the voltage to become distorted. Excessive voltage distortion can lead to equipment malfunctions and premature failure resulting in downtime and increased operating costs.
Proper grounding is an extremely important aspect of maintaining power quality within a home or facility. Electric panels should have dedicated grounds pulled to them from the main ground point or transformer derived ground point. The neutral should be grounded only at the main ground point or transformer derived ground. The neutral and ground should not be tied in the distribution panels. Equipment safety grounds should not be bonded to the neutral.
Uninterruptible Power Supply and Emergency Power Generation
Uninterruptible Power Supply (UPS) is commonly used to provide protection against power sags and outages for predetermined lengths of time. Basic or lower level units simply provide protection for shorter periods of time to allow for an orderly shut down of systems, hopefully preventing data or process loss. Advanced or upper level protection typically provides electrical isolation for larger systems and ride through capability while the facility switches from purchase power to generator.
The need for UPS should be discussed, especially as it pertains to server applications. The UPS must be specified to properly serve its purpose, while not adversely impacting the facility power infrastructure through voltage notching or harmonic distortion.
Emergency power generation provides electrical power for periods of extended utility outage. There are many different kinds and sizes of generation, depending on facility process and life safety issues. It is important to understand that altitude, weather conditions, fuel variables, and especially load profiles will affect an emergency generators ability to successfully maintain a desired load. Emergency generators that power electronic loads must be properly specified, tested and maintained if they are expected to perform adequately during emergency conditions.