| abstract |
An electrical insulation oil that excels in biodegradability, having low viscosity at low temperature, and that even when a quantity of moisture is mixed therein, is low in the deterioration of insulation performance, ensuring satisfactory electrical characteristics. In particular, there is provided an electrical insulation oil comprising as a main component an ester composed of neopentyl glycol and at least one C7-C10 linear or branched carboxylic acid and having a kinematic viscosity at 0°C of 10 to 200 mm2/s, a dielectric breakdown voltage of ≥ 30 kV, a biodegradability of ≥ 60% and a fluid point of ≤ -30°C. |