Degraded Paper Fiber From Transformer Oil
This degraded paper fiber is from an oil sample collected from a 8400kVA transformer. This
transformer was reportedly gas blanketed and sealed. The presence of this paper fiber and others similarly degraded
indicates severe aging of the paper insulation in some areas.
Transmitted Oblique Off Crossed Circular Polarized Light
Paper is used as a primary insulation in the core of transformers. This material will degrade hydrothermally like other cellulose
materials in a transformer over time.
Significance in the Environment:
This type of degradation indicates temperatures typically over 90 degrees Celsius and elevated moisture content.
Hydrothermally paper fiber often exhibits tears normal to the long axis of the fiber. The birefringence is
typically below 0.01 by the time these tears are evident. The paper fiber may be quite irregular in shape, having lost
mechanical integrity in all layers of the fiber.