To the untrained eye, problems in electrical distribution systems or the equipment connected to the circuit may not be recognizable as power quality problems. When no immediate problem is apparent, it may be written off as just an old breaker that needs replacing or a one-time nuisance reset. You might look at types of loads on the system and monitor for harmonics, unbalance or disturbance patterns.
Harmonic distortion issues and voltage and current anomalies represent the areas where common problems in power quality occur. Voltage and current anomalies can produce problems; however, many can be corrected before they damage equipment. Use this chart to help spot the symptoms:
| Issue | Symptoms | Potential causes |
|---|---|---|
| Dips or Sags |
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| Swells |
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| Transients |
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| Interruptions | Equipment shutdowns | Momentary loss of utility power |
| Unbalance | Overheated three-phase motors and transformers |
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| Harmonics |
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