Understanding Infrared Thermography Reading 3

Inductive currents flowing with in ferrous components or elements that are
within the magnetic field of large equipment (i.e., the main generator in a
power plant) can cause excessive heating. Warm areas can appear in motor
frames and structural elements and several examples have been documented
where steel bolts have been inappropriately used to replace nonferrous bolts
in framework supporting large rotating machinery. Heat caused by inductive
heating does not always lead to failure, but should be documented by the
conscientious thermographer. Energized grounds occur in plants and facilities,
sometimes as the result of partial insulation breakdown in an operating
element. These findings are, in many cases, considered life safety situations.
Because an energized ground connection is usually extremely hot , there is
seldom difficulty identifying it thermographically. The problem is tracing the
cause. which may be elusive. The ground connection may also be carrying
induced currents because of a breakdown of an element in close proximity.
Most often the diagnosis requires considerable input from knowledgeable
facilities personnel.
Charlie Chong/ Fion Zhang