Standard transformer oil

Conventional transformer insulating oil pilot project (physical - chemical nature of the project) 1 "at 20/40 ℃ ℃ when the specific gravity of more than 0.895 (new oil). 2 "at 50 ℃ Viscosity (Si Gele) does not exceed 1.8 (new oil). 3 "bright spot (℃) of not less than 135 (running better than new oil reduces oil above 5 ℃). 4 "Freezing point (℃) is not higher than -25 (the monthly average minimum  circuit breakers of not lower than -10 ℃ areas, such as the freezing point of -25 ℃ without insulating oil, allowing the use of a freezing point of -10 ℃ oil). 5 " power transformers  mixture no. 6 "free carbon None. 7 "ash content of not more than (%) 0.005 (0.01 in operation oil). 8 "active sulfur no. 9 "acid value (KOH mg / g oil) not more than 0.05 (in operation oil 0.4). 10 "sodium test a rank of 2. 11 "Stability: <1> oxidized acid value not greater than 0.35. <2> The precipitate after oxide content (%) 0.1. 12 "Electrical insulation strength (standard gap breakdown voltage) is not less than (KV): <1> for 35KV and above transformer (40). <2> for 6 ~ 35KV transformer (30). <3> for 6KV following transformer (25). 13 "was  air circuit breaker in water, acid or burial no. 14 "water free. 15 "at the time of +5 ℃ transparency (sung in vitro) and transparent. 16 "tgδ and volume resistivity (if after oil immersion transformer tgδ and C2/C50 values ​​increased should be measured) tgδ no more than (%) at 20 ℃ to 1 (run 2), at 70 ℃, 4 (run 7), the volume resistivity (not specified value it should be compared with a minimum value).