Solving PQ starts by observing and collecting all the available information. A disturbance log is a valuable tool in identifying the source of power quality problems. Before starting a log, it is important to develop an understanding of the facility, the equipment being affected, wiring and grounding practices, operations schedules and other operating procedures. Combining power monitoring with a disturbance log is extremely useful in correlating recorded data with disruptions to equipment or processes within your facility. Listed below is the information needed to help troubleshoot problems.

What happened?

• Nature of problems (data loss, nuisance trips, component failures, control system malfunctions, etc.)
• Characteristics of the sensitive equipment experiencing problems (equipment design information, application guide information, etc).
• Coincident problems or known operations (e.g. chiller start) that occur at the same time.
• Possible sources of power quality variations within the facility (motor starting, capacitor switching, power electronic equipment operation, arcing equipment, etc.)

What was affected?

• What equipment failed and how (including error or fault codes).
• Any existing power-conditioning equipment being used.
• Electrical system information (one-line diagrams, transformer sizes and impedances, load information, etc.).
• Estimated cost of disturbance.

When?

• When do problems occur (date and time)?
• Downtime of affected equipment.
• Is there a pattern?