2. CONTENTS
• Oil Immersed Power Transformer
• What is Eco-Friendly Insulating Oil
• Characteristics of the Ester Oil
Immersed Power Transformer
• Applications Eco-Friendly Insulating
Oil
3. Ester Transformer Fluids
Fire Safe, K-Class, Biodegradable Insulating Liquids
a) Synthetic Ester : Create through the reaction of alcohol with short
chain fatty acids
b) Nature Ester : Bio-Based, Occur as Seed oil occur from Plants such as
Canola seed and soya seeds.
5. Type of Eco-Friendly Insulating Oil
- Biodegradable transformer Insulating oil (Ester oil)
a) Natural Ester – Ester Oil Extracted from Vegetable
b) Synthetic Ester oil – Industrially Synthesized Ester oil
Characteristics of Eco-friendly Insulating Oil
a) High Biodegradability(Ecologically Friendly)
b) High flash and Fire points (Reduce fire Risk)
b) High degree of Water saturation (Extended Transformer
Life)
Subject Mineral Oil Natural Ester Oil
Raw Material OIL Vegetable
Flash Point 1.0 2.2
Viscosity 1.0 3.6
Freezing Point 1.0 0.4
Dielectric Permittivity 1.0 1.5
Water Saturation Poor Excellent
Oxidation Limit Good Poor
Comparison of Mineral Oil and Natural Ester Oil
Natural Ester Oil Synthetic Ester Oil
Envirotemp FR3 Envirotemp 200
MIDEL eN 1204 MIDEL 7131
BIOTEMP
Eco-Friendly Insulating Oil Products
7. High biodegradability to cause less environmental pollution and high flash and fire
point to lower the fire risk
Non-toxic and low environmental pollution
Ester oil is 94% biodegradable after being exposed to soil for
28days
Excellent Fire Safety
Non-dangerous K class insulating oil with the flash point of 300
deg.C or higher
Ester oil is twice or more safer against fire than paraffin-
based insulation oil
Aerobic Aquatic Biodegradation Graph
Flash Point and Fire Point of
Insulation oil
Fire Risk Grade of Fluid
8. Reduction of moisture in solid insulator inside the transformer to increase the
insulator life effectively
Reduction of operating and maintenance cost
Mineral oil Ester liquid oil
Minimum high-temperature solid insulation
thermal class
N/A 130 155 180
Top liquid temperature rise (K) 60 80 80 80
Average winding temperature rise (K) 65 85 100 115
Hot-spot temperature rise (K) 78 110 135 160
Degree of Water saturation according
to temperature of each oil type Leverage higher thermal capability Limiting the maximum temperature increase
[IEC 60076 -14]
a)Significant life expectance increase of Ester oil transformer at normal life expectance condition (110 C) mineral oil transformers.
b) Maximum operating temperature increase of 20 C at the same expectance as the mineral oil transformer
Upto 20% load rate increase
