Harmonic characteristics, limits and design strategies for compliance in office buildings

In Hong Kong, the low voltage distribution system in multi-tenanted, high-rise, air-conditioned office buildings is a small-scale power system. The matter of harmonics in the system is of increasing concern. To avoid potential disputes or problems related to harmonics, it is necessary to clarify the responsibilities of all parties involved. This paper identifies harmonics requirements for the building operator. Two different types of points of common coupling (PCCs) are introduced. The IEEE harmonic limits at these PCCs are discussed and compared with harmonic data collected in buildings. It is found that harmonic distortion levels at the PCC exceed the limits in some cases. Strategies for harmonic compliance in office buildings are identified, especially those which can be adopted in design of electrical installations.