A site survey is a visual inspection of your facility’s electrical system to make sure it isn’t the source of the power quality issue. According to the Electric Power Research Institute (EPRI), 80 percent of all power quality issues are caused by improper wiring or grounding within a customer’s facility. Because of this high prevalence, the first area of inspection during a site survey should be wiring and grounding checks.
The following are the goals of a site survey:
- Determine the wiring and grounding system’s condition and adequacy.
- Determine the quality of the AC voltage at the utilization point.
- Look for any loose connections.
If the power quality issue affects your entire building, start by inspecting the electrical service entrance for defective or loose connections. Measure the resistance of the grounding system with an earth-ground tester. Readings of voltage and current should also be taken and documented. Each panel in the power distribution system supplying the impacted equipment should be inspected or validated from this point forward. Voltage measurements, appropriate conductor termination, and ground and neutral impedance levels should all be included in the verification testing.
Power quality issues can also be caused by temporary power outages and voltage sags in the electrical distribution system, which can affect your entire operation. If you phone your Electric Company, you can find out if there was an electricity outage
Check the wiring and grounding for the equipment to confirm that it is properly sized and connected if a power quality problem is affecting only certain equipment in your facility. Before the equipment starts up, during startup, and after it has been functioning for a while, voltage and current measurements should be collected at the input to the equipment. These tests may aid in resolving a power quality issue, particularly if one arises following any equipment upgrades, replacements, or facility expansions.