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IR Inspections of Single Phase Power Panels
Tip written by: Infraspection Institute

Determining exceptions in single phase power panels is often challenging due to the absence of appropriate reference components. In this Tip, we offer suggestions for properly inspecting these panels.

Infrared inspections of single phase circuits are often challenging due to the absence of similar components under similar load. Unlike polyphase panels, single phase power panels typically contain circuits of different sizes. Oftentimes, these circuits are under widely varying loads. Depending upon power usage, many circuits may be under zero load causing other circuits to appear quite ‘hot’ by comparison.

Prior to performing an infrared inspection of single phase panels, make certain that the panel is under adequate load. When inspecting, keep the following in mind:

• Inspect panels in an orderly fashion working from line to load side for all circuits. When possible, compare similar components under similar load to each other.
• Inspect each overcurrent device for uneven heating between the line and load side connections. Check all connections within the panel to ensure that hot spots do not exist.
• Check warm conductors for load using a true RMS sensing ammeter. Don’t forget to include neutral conductors.
• Document all exceptions with a thermogram, control photo and all pertinent data including time, date, and load conditions.
• Be aware that some devices such as GFCI breakers may normally appear warm due to their construction and/or operation.

Lastly, be certain to observe all necessary safety practices when working on or near energized electrical equipment.

Infrared inspection of power distribution systems is one of the many topics covered in the Level I Infraspection Institute Certified Infrared Thermographer® training course. For information on thermographer training or to obtain a copy of the Standard for Infrared Inspection of Electrical Systems & Rotating Equipment, visit us online at www.infraspection.com or call us at 609-239-4788.

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