Power
Midel is successfully operating in power transformers with ratings up to 238 kV / 135 MVA including those in high risk areas such as substations. Our customers choose Midel for many reasons but the major factors for the power sector are fire safety, environmental protection and safeguarding against corrosive sulphur.
Midel has a 100% fire safety record that spans over three decades. Unlike mineral oil, Midel has a high fire point making it ideal for use in high risk areas. For example Vattenfall use Midel in a high voltage transformer (151kV) in Storuman to reduce the risk of fires in tunnels.
Midel is also environmentally friendly because in contrast to mineral oil it is readily biodegradable and non-water hazardous. This has been crucial in many projects for example VA Tech EBG manufactured a Midel power transformer because it was to be used near Lake Malgomaj, an ecologically sensitive area.
Recently the transformer industry has reported the failure of multiple large units due to the presence of corrosive sulphur. Midel has been tested by independent laboratories to ASTM D1275 B, Standard Test Method for Corrosive Sulphur in Electrical Insulating Oils and IEC 62535, Insulating liquids - Test method for detection of potentially corrosive sulphur in used and unused insulating oil. It was found to be Non-Corrosive.
It is important to note that design changes may be necessary when using ester fluids in power transformers. There is evidence from laboratory research that ester fluids have different dielectric behaviour to mineral oil, especially under lightning impulse voltage loads. For further information please contact the Technical Department.
Benefits of MIDEL 7131 in Power Transformers
Increased Fire Safety
- K-class high fire point (>300°C) to IEC 61100
- 100% fire safety record
- FM Global approved transformer fluid
High Performance
- Good oxygen stability, suitable for use in free breathing or sealed systems
- Robust and stable, conducive to lower levels of maintenance
- Greater moisture tolerance than mineral oil, silicone liquid and natural ester
- No corrosive sulphur - ASTM D1275 B and IEC 62535
- Suitable for use with modern tapchangers - details available on request
- Proven up to 238kV
Greater Environmental Protection
- Readily biodegradable according to OECD 301 and fully biodegradable according to IEC 61039
- Non-toxic and non-water hazardous
Excellent Customer Service
- Multilingual commercial team
- First-rate customer care
- Continued technical support from the transformer fluid experts
