BS EN IEC 60296 pdf free download
BS EN IEC 60296 pdf free download.Fluids for electrotechnical applications – Mineral insulating oils for electrical equipment.
4.4 Performance
These are properties that are related to the long-term behaviour of oil in service and/or its reaction to high electrical or thermal stresses. In terms of performance, transformer insulating oils are divided into Type A (Table 3) and Type B (Table 4).
4.5 Health, safety and environment (HSE) properties
These are oil properties related to safe handling and environmental protection.
NOTE Examples can include flash point, density, PCA (polycyclic aromatics) and PCB/PCT (polychlorinated biphenyls/ terphenyls) content.
5 Classification, labelling, identification, general delivery requirements and sampling
5.1 Classification and labelling
5.1.1 Classes
For the purposes of this document, mineral insulating oils are classified into two classes:
— transformer oils;
— low temperature switchgear oils.
Within the transformer oils two groups of oils are defined: Type A (Table 3) and Type B (Table 4).
Type A insulating oils are fully inhibited (“I” according to 5.1.2) and deliver higher oxidation stability than Type B.
Type B insulating oils can be uninhibited (“U”), trace inhibited (“T”) or fully inhibited (“1’) and deliver good resistance to oil degradation and provide good oxidation stability.
Inhibitor concentration for inhibited oil in service needs to be monitored and eventually maintained. This is described in lEG 60422.
NOTE During base oil refining some components such as aromatic and polycyclic aromatic compounds are removed depending on the severity and type of refining process.
Uninhibited oils are typically made from base oil(s) with the aim to retain a balance of removable components, some of which are easily oxidized, while others provide some protection against the normal oxidation process. The refining process is optimized to retain certain sulphur and aromatic compounds which act as natural antioxidants. However, since the natural antioxidants are not as effective as synthetic antioxidants, the uninhibited oils will exhibit less oxidative stability compared to inhibited oils.
Uninhibited oil contains a certain amount of so called natural antioxidants, some of them present from the beginning (mostly sulphur-containing acting as secondary antioxidants). others being formed as intermediates by oxidative processes (mostly oxidation of aromatic compounds then acting as radical scavengers). Inhibited oil is a blend of base oil(s) with a synthetic antioxidant. The additive response and the resulting oxidation stability of the inhibited oil depends very much on the refining severity. The antioxidant is added to control the oxidation processes. The inhibitor acts as radical scavenger and protects the base oil hydrocarbons — depending on the degree of refining — from oxidation. Oils with very high oxidative stability are inhibited oils and can be achieved by blending very severely treated base oil and antioxidant.
5.12 Antioxidant (oxidation inhibitor) content
Mineral insulating oils are classified into three groups, according to the content of antioxidant additive:
— uninhibited mineral insulating oils: marked with U;
— trace inhibited mineral insulating oils: marked with T;
5.1.3 Lowest cold start energizing temperature (LCSET) LCSET shall be -30。C unless otherwise specified. If a different LCSET is specified it shall be chosen from values of Table 2. 5.1.4 Labelling and ordering designation For the purpose of declaration, mineral insulating oils shall be labelled as: V: unused mineral insulating oil as defined in 3.8. R: recycled mineral insulating oil as defined in 3.9. The ordering designation for insulating oil according to IEC 60296 shall follow the order: Equipment/Declaration/Type/Antioxidant according to the scheme in Table 1.BS EN IEC 60296 pdf download.
