Moisture Tolerant Fluids

MIDEL ester transformer fluids are among the most moisture tolerant transformer fluids available. They will absorb far more water than mineral oil without compromising their dielectric properties.

Moisture is known to accelerate cellulose degradation which in turn is a significant factor in transformer lifetime reduction. MIDEL fluids have the potential to keep cellulose drier, thus extending the life of the transformer.

Moisture tolerance is particularly important in areas with high humidity or risk of moisture ingress. Mineral oil can become saturated with small amounts of moisture, reducing its effectiveness as a dielectric fluid but MIDEL fluids can tolerate substantially larger amounts of moisture in comparison and still work effectively.

MIDEL for Superior Moisture Tolerance

  • Absorbs large amounts of moisture with no reduction of breakdown voltage
  • Allows moisture to migrate from cellulose into the fluid
  • Potentially keeps the cellulose drier and slows the rate of ageing
  • Very high saturation limit making precipitation of free water virtually impossible
  • Reduces risk of bubble formation
  • Retrofilling*

* Example: a mineral oil filled distribution transformer at a UK port was going to be de-commissioned due to high moisture levels; a retrofill with MIDEL 7131 brought it back to a state of safe operation. Read the Case Study here.