Why are moisture tolerant fluids important?

Moisture inside transformers is known to accelerate cellulose (paper) degradation, which in turn is a significant factor in transformer lifetime reduction.

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 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. These transformer fluids have the potential to keep cellulose drier, thus extending the life of the transformer.


MIDEL fluids for superior moisture tolerance

If you are concerned about the effect moisture is having on your transformers, MIDEL ester fluids can provide the perfect solution. Here’s how they help:

  • Absorb large amounts of moisture with no reduction of breakdown voltage

  • Allow moisture to migrate from cellulose into the fluid

  • Potentially keep 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 existing transformers


Retrofilling wet transformers

Field trials conducted by M&I Materials show that MIDEL fluids can be used to bring transformers with very wet cellulose back into operation by a simple retrofilling procedure.

One particular mineral oil filled distribution transformer was going to be decommissioned due to high moisture levels; a retrofill with MIDEL 7131 brought it back to a state of safe operation. More than 5 years later, the unit is still in perfect working order and has not required any further maintenance.


Wet transformers?

Talk to our team about how ester transformer fluids can help