EIOS T2-HI Electrical Insulating Oil

About This Product

EIOS T2-HI is a highly refined mineral insulating oil supplied to IEC 60296:2020, Table 3, as a Type A inhibited grade for transformer and switchgear service. The base oil is dosed with a synthetic antioxidant, DBPC in most cases, at a controlled level: inhibitor content, determined by IEC 60666, is specified at 0.08–0.40 (typically 0.35). The oil is non stray gassing, with no detectable PCB or DBDS.

Oil in a working transformer ages through a free-radical chain reaction. The inhibitor breaks that chain early, each antioxidant molecule giving up a hydrogen atom to neutralise a radical before it can attack more oil. As long as some inhibitor is left, oxidation barely moves. In standard oxidation tests this shows up as a far longer induction period, and in hot, heavily loaded units as longer service life. The protection is sacrificial, however: every molecule that stops a radical is spent, and when the reserve runs out the oil oxidises fast and with little warning. Operators therefore trend inhibitor content together with water, acidity and dissolved gas analysis, and re-inhibiting the oil is an accepted maintenance step. Blending with uninhibited oil calls for a compatibility assessment first.

Typical duties are switchgear, reactors and capacitors as well as power and distribution transformers, particularly units run hot or at high load, for new filling and retrofilling alike. BG Petro Chemicals supplies T2-HI against agreed limits for flash point, water, acidity, breakdown voltage, dielectric dissipation factor, inhibitor content and oxidation stability.