How do Midel ester transformers fluids perform in the cold?
There are a range of MIDEL fluids to suit various climatic conditions. The performance of each fluid under cold climate conditions can be characterised by the pour point.
In line with other soy-based natural esters, the pour point of MIDEL eN 1215 is around -18°C, meaning that enhanced engineering controls may be needed for the coldest climate locations, e.g. heat tracing on conservator pipes.
This requirement reduces with rapeseed-based MIDEL eN 1204 which has a lower pour point of -31°C. For extremely cold climates users may wish to opt for synthetic ester-based MIDEL 7131 which has the lowest pour point. MIDEL 7131 is in operation in the coldest regions of the world, including Siberia.
Transformer Fluid Pour Point
For more information on how Midel transformer fluids perform in cold weather, download the technical sheet: Cold start behaviour and dielectric performance.
More questions on ester fluids?
This post is one of the 15 top questions we get asked on retrofilling transformers with ester fluids. Here is the full list of the frequently asked questions on ester fluid retrofilling: