Thermography training at Rockwell

Thomas Okamura

Thomas Okamura

— 2 min read
Thermography training at Rockwell

Today we had a training session on thermography.

The most important part of the session was the hands-on. Once we got started, the first panel we opened had a thermal anomaly.

Thermal anomaly found.
Temperatures at 143 on a breaker terminal

Before the images above we actually measured 164degC. This is why Proactive Maintenance principles need to be applied before there's a failure.

The current reading on the single phase breaker was 13amps. I believe the wire was a 12 guage, and the ampacity is 20amps. I also think the wire is THW, which according to NETA standards has a 75degC maximum temperature limit.

The principle I stressed was the Arrhenius Law, that there is a strict mathematical relationship between temperature and chemical reaction rate.

When we opened the circuit, disconnected upstream power, and pulled out the conductor, you can see what 164degC can do to copper.

Burnt copper. No way just tightening this would do anything.

This is how it looked like after clipping the tip and re-terminating. Amperage readings measured 11A instead of 13A.

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