Harmonics

The Electrical System Harmonic Program is designed to promote maximum operating reliability of the facility electrical system along with the sensitive electronic equipment such as computer equipment, PC's, workstations LAN/WAN equipment /systems, POS, telecommunication equipment, fire and security systems, and motor systems (e.g. VFD's) while providing for a safe working environment.

The Electrical System Harmonic Program is not only a standalone service but is also part of the Power Quality and Power Management Programs.

The Electrical System Harmonic Program is used for lighting system retrofit or upgrades, expansions or upgrades of sensitive electronic equipment, or other investments in new electronic technology advances. This proactive program is used to gather the present electrical system harmonic profile for modeling and predictability of the electrical system's response to the proposed changes. This provides the necessary information to determine if the present electrical system can support the proposed changes in a safe and efficient manner.

There are many factors that determine how long the Electrical System Harmonic Program will take to complete depending on the size of the facility, the scope of the work, and the program category selected. The Electrical System Harmonic Program is divided into four phases. The first phase is the Harmonic Survey. The average survey can typically be completed in one day. Once completed, all the findings, modeling, and predictability data are documented in a report along with recommendations for any changes that may be required. The second phase is to either support, assist, or perform the changes that may be required. The third phase is a verification of any changes made. This is performed to insure that changes have been completed correctly and that no hidden deficiencies now surface due to the changes. The fourth phase is a Harmonic Reverification Survey. This is to insure that the modeling and predictability data matches the operating electrical system data for the completed project.

The Harmonic Survey is made up of three distinct services. These services are an electrical system evaluation, harmonic monitoring, and a conductor study.

The electrical system evaluation encompasses inspecting and testing the electrical system. The electrical system evaluation begins at the electrical service entrance and continues on to the equipment. The inspection process examines the electrical system from the stand point of the National Electrical Code, industry electrical standards (e.g. Institute of Electrical and Electronics Engineers), personal safety requirements (e.g. OSHA), manufacturers procedures, and internal company practices. The testing process covers the earthing system, electrical service grounding and bonding methods, and electrical system distribution. The electrical system evaluation provides the necessary information in determining if the electrical system can properly support the present and future loads.

Harmonic monitoring is performed using a graphic power line data acquisition instrument for recording and analyzing electrical system operating information. Some of the information recorded covers voltage and current harmonics, power factor, and electrical anomalies. This recorded information is used to determine if the electrical system harmonic profile is within an acceptable range as compared to industry standards, manufacturers parameters, and internal company specifications prior to as well as after the proposed changes.

The conductor study consists of performing calculations on the circuit conductors using the harmonic spectrum to determine if the present conductor size can safely handle the load current.

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