What are the acetylene limits in transformer oil?

Ideally, there should be no detectable acetylene in transformer oil under normal operating conditions. Even a small amount of acetylene (greater than 0.5 parts per million or ppm) can be a cause for concern and may indicate arcing within the transformer. If acetylene is detected, it typically triggers a more detailed investigation through Dissolved Gas Analysis (DGA) to determine the extent of the fault and the necessary corrective actions.