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Power Quality (PQ) Problems

We are increasingly reliant upon sensitive electronics to perform critical functions for manufacturing processes, communications, commerce and government, which are inherently susceptible to power quality problems. Facilities utilizing sensitive electronics for data processing and automated process control can improve operating efficiencies by the implementation of a surge suppressor.

Some of these power disturbances are obvious, while many are almost unnoticeable; but they all cause problems that can seriously disrupt your productivity, from lost data and system lock-ups to communications errors and hardware failures.

Electrical noise is spread by AC/DC motor controls, electronic lighting ballasts, printers, photocopiers and computers. Over time, and in connection with low-voltage spikes, electrical noise can cause sensitive electronic components to fail for no apparent reason.

Over 80% of voltage spikes and impulses are caused by equipment inside your and/or neighboring facilities.
The starting and stopping of electric motors such as those used in automated systems and manufacturing (i.e., machine tools, elevators, HVAC, etc.) can create a continuous stream of 250V to 3000V transients. DC drives, variable speed AC drives, and DC power supply switching are other sources of transients and electrical noise.

Transient over-voltages are a major cause of malfunction or total failure of electronic circuitry and equipment. These transients occur whenever there are sudden changes in a power distribution system, whether resulting from lightning or utility-switching disturbances on incoming power lines. These can create transients so intense they literally destroy sensitive electronics. Energy changes within the system are responsible for more than 80% of surge suppression events. With such changes, voltage spikes are created by the energy stored in reactive components. These voltage impulses can destroy semi-conductor devices, reduce the dielectric strength of insulation, damage electromechanical contacts and cause errors of logic circuitry by stray signals imposed on logic reference levels.

Power outages are the most visible of power quality problems but are infrequent compared to disturbances such as electrical noise, spikes, and voltage transients which are less visible but always present. For this reason, your sensitive electronic equipment needs constant power protection.

The three most prevalent types of system failure are: Catastrophic Failure, usually caused by arcing components or destroyed printed circuit traces; System Degradation of the sensitive electronic components and chip sets, continuously weakening until the component fails (normally this damage is not visible); and System Disruption power quality disturbances which are responsible for most of the unexplained and more elusive system lock-ups, data errors, communication errors and slow system operation faults.

Transients may occur either in repeatable fashion or as random impulses.
Repeatable transients, such as commutation voltage spikes, inductive load switching, etc., are more easily observed, defined and suppressed.

Random transients are more elusive. They occur at unpredictable times, at remote locations and require installation of monitoring instruments to detect their occurrence. Frequently, random transient problems arise from the power source feeding the circuit. These transients create the most concern because it is difficult to define their amplitude, duration and energy content. Random transients are generally caused by switching parallel loads on the distribution system, although they also can be caused by lightning.

Power lines running overhead or even underground can have voltage induced either by a direct or indirect lightning strike. The voltage induced on wiring is typically a very short but high-energy pulse.

Electrical power quality problems cost the United States industries over $100 billion annually
80% of voltage surges and transients are caused by changes in electrical demand, inside the user's facility