What is the source of Power Quality problems?

Most people believe that all power quality problems can be traced to the power coming from the utility. The reality is more complex. The source of a power quality problem can be the utility, but it also can be the facility or even the equipment inside the facility. Utility Power quality problems that begin with the utility often have the greatest impact on a facility’s operation. Typical utility-generated events range from a breaker clearing, which can produce sag, undervoltage or outage, to arcing contactors, which may generate impulse. Stopping or limiting the impacts of utility-generated events must be done where electrical service enters the facility. Facility – The building typically produces the majority of power quality problems, partly because the normal use of energy creates power-line events that can affect the facility’s equipment. Typical facility problems include loose connections, overloaded circuits and transformers, ground loops and wiring errors. Beyond comprehensive plant maintenance, addressing these problems may include the use of transformers with some output filtering. Equipment Equipment — particularly the new generation of automated and computer-based technologies — can produce power quality impacts through normal operation. The impacts of routine activities such as equipment turn-on/off can include impulse, sag, surge, voltage distortion and repetitive disturbances. Mitigation equipment between the load and the facility wiring can correct the problems.