What types of contamination affect silicone oil, and how can they be prevented?

Contaminations include:

Moisture: Lowers dielectric strength and promotes degradation.
Particulates: Metal particles, dust, and fibers can cause electrical discharges.
Gases: Air and other gases reduce insulating properties.
Acidic Byproducts: Resulting from oxidation, they can corrode transformer components.
Prevention methods:

Proper Sealing: Ensuring transformers are sealed to prevent ingress of moisture and air.
Desiccant Breathers: Using devices that absorb moisture from the air entering the transformer.
Clean Handling Practices: Maintaining cleanliness during oil sampling and maintenance.
Regular Monitoring: Early detection of contamination allows for timely corrective action.