FAQs on Power Quality
How is Power Quality measured?
Power quality is measured by the consistency of the voltage supplied at the customer's meter. The amount of voltage availability may fluctuate or change due to controllable or uncontrollable circumstances.
What kind of equipments can be affected by Power Quality problems?
Any types of electrical equipments can be affected. Standard building systems such as lighting, HVAC and communications equipments are frequently affected. The most costly Power Quality problems often involve more sensitive high-tech equipments such as computers and data systems.
How do I know if my business has Power Quality problems?
If you answer YES to any of these questions, you are likely to be experiencing a Power Quality problem:
- Are you experiencing premature failures of electronic equipments or motors and drives?
- Your adjusted speed drives often trip into offline mode?
- Your computer tends to shut down inexplicably?
- Your computer’s screen tends to jitter?
- You are experiencing equipment problems during or shortly after lightning storms?
- Your circuit breakers tend to trip without being overload?
- Your transformers cases are extremely hot to the touch?
- Your equipments tend to malfunction at the same time of the day?
- Your automated systems fail for no apparent reason?
- Certain electronic systems tend to function in one location but not in another location?
- Do certain electronic systems work in one location but not in another location?
- Your lights tend to dim or flicker?
What causes Power Quality problems?
The most common causes of Power Quality problems include lightning strikes, equipment failures, vehicle accidents, weather conditions, neighbouring businesses and abnormal operation of utility equipments.
External causes are not necessarily from electrical lines; any wire entering a building may cause problems, including communication and data lines, telephone and coaxial lines as well as satellite connections.
Are there National or International Standards that describe issues on Power Quality?
Some of the international standards that explain the power quality phenomenon are:
- IEC 61000-2-1: Definition of Electromagnetic Compatibility (EMC) EMC is concerned with the possible degradation of the performance of electrical and electronic equipments due to the disturbances present in the electromagnetic environment, in which the equipment operates
- MS IEC 61000-2-4: Compatibility levels in industrial plants for low frequency conducted disturbance
- MS 1760:2004: Guide on voltage dips and short interruptions on Public Power Supply System. The original standard is the IEC/TR 161000-2-8
- MS IEC 61000-4-11: Immunity test for voltage dips, short interruptions and voltage variation for equipment less than 16 Amp
- MS IEC 61000-4-34: Immunity test for voltage dips, short interruptions and voltage variation for equipment more than 16 Amp