What type of high-temperature event can lead to nitrogen and high hydrogen levels in oil?

The type of high-temperature event that can lead to elevated nitrogen and high hydrogen levels in oil is arcing. This phenomenon occurs when an electrical discharge passes through the insulating oil, producing intense heat that can break down the oil's molecular structure. During arcing, the extreme temperatures can cause the cracking of hydrocarbon molecules in the oil, releasing hydrogen gas. Additionally, nitrogen can be introduced into the oil under these conditions, possibly due to the breakdown of surrounding materials or contamination from the environment.

Understanding arcing is crucial in the context of substation maintenance, as it signals potential failures in electrical insulation systems. The presence of high levels of hydrogen and nitrogen is a clear indicator that the insulation oil might be compromised, necessitating immediate investigation and intervention to prevent further damage or risks within the electrical system.