Businesses and organisations are now totally BM-N3 (25TH) dependent on electricity to run their data and voice processing systems. Power failures – short or long – can be devastating if they are not protected by UPS (uninterruptible power supplies).
However, a lesser-known threat – but equally troublesome – is that of power quality and problems in supply.Electrical Noise, which is a high-frequency sound, can be caused by flickering lights, cable and switchgear faults and occasionally interference from electronic equipment such as radio transmitters.
The causes of power quality issues are usually environmental: weather phenomenon (local lightning strikes and electrical storms), heavy loads being switched into and out of the supply; load shedding; cable and switchgear faults and sometimes interference from radio transmission equipment. They can cause hardware to lock, fail or re-boot resulting in equipment wear-and-tear and lost or corrupted data.
Power Problems. Sags are common: short-duration voltage reductions below the mains supply level that can last for several seconds. One of the most common causes is switching heavy loads (air-conditioners, motors, industrial machinery) into and out of the local electricity circuit.
Conversely, the same issues can cause surges, which are short-duration voltage increases above the mains power level, which can also last for several seconds. When voltages rise above the acceptable input window of a PSU (power supply unit), for example, built-in cut-out protection activates resulting in a system crash.
Brownouts are less common now but may become more frequent as demand for electricity continues to increase. They are classified as long-term reductions in mains power supply that can typically last for several days and compromise the effectiveness of other equipment, such as lighting.
Spikes and Transients are fast-moving, high-energy bursts (some in excess of 6kVA) lasting only a few milliseconds, superimposed onto a normal mains power supply. Their intensity can cause damage to circuit boards, processors, memory loss and data corruption. Possible causes are lightning strikes, electrical storms, local load shedding, relay-based thermostats and inductive motor loads.
