Transmitted Off Crossed Circular Polarized Light and Reflected Darkfield Illumination
Silver arcing spheres are generated when an arc is discharged in the transformer under the cover of oil. It is the
result of molten silver being formed by the arc and ejected into the oil by the rapid thermal expansion of the metal under
the molten metal. The size of the arc particle is an indication of the strength of the arc.
Significance in the Environment:
There is some arcing to a silver surface going on in this transformer or there has been some mixing of oil from a
circuit breaker or load tap changer compartment.