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1
Overview
1.1 Procedure for Investigating Power Quality
By measuring power quality parameters, you can assess the power quality and identify the causes
of various power supply malfunctions. The ability of the instrument to measure all power quality
parameters simultaneously makes this process a quick and simple one.
The following is the description of the investigation process for the power quality.
Step 1: Clarifying the purpose
To nd the cause for the power supply malfunction
A power supply malfunction such as an equipment failure or malfunction has occurred and
you wish to address it quickly.
Go to Step 2 (p. 16).
To assess power supply quality (power quality)
There is no known problem with the power supply, and you just want to assess the power
quality.
• Periodic power quality statistical investigation
• Testing after the installation of electric or electronic equipment
• Load investigation
• Preventive maintenance
Go to Step 3 (p. 16).
Step 2: Identifying the malfunctioning component (measurement
location)
Check the following:
(1) Where is the issue occurring?
• Principal electrical system
Large copier, uninterruptible power supply, elevator, air compressor, air conditioning compressor,
battery charger, cooling system, air handler, time-controlled lighting, variable-speed drive, etc.
• Electric distribution system
Conduit [electrical conduit] damage or corrosion, transformer heating or noise, oil leak, circuit
breaker operation or overheating
(2) When does the issue occur?
• Does it occur continuously, regularly, or intermittently?
• Does it occur at a specic time of the day or on a specic day of the week?
(3) What type of investigation (measurement) should be performed to nd the cause?
• Measure the voltage, current (power) continuously to analyze voltage and current trends when
the issue occurs.
• Concurrent measurements at more than one location
Examples:
• Dedicated systems lines in the electrical substation (can be measured only by the power
companies)
• High-voltage and low-voltage lines of the service entrance
• Distribution panels and switchboards
• Power feeder and outlets of power supply for electric and electronic equipment
1 Overview
1
Overview