As the transformer runs for a long time, oil filling is unavoidable. At the same time, equipment after maintenance, oil change is also present.

1、电气设备充油不足需要补充油时，应优先选用符合相关新油标准的、未使用过的变压器油。好补加同一油基、同一牌号及同一添加剂类型的油品。补加油品的各项特性指标都应不低于设备内的油。当新油补加量较少时，例如小于5％时，通常不会出现任何问题；但如果新油的补加量较多，在补油前应先做油泥析出试验，确认无油泥析出，酸值、介质损耗因数值不大于设备内油时，方可进行补油。

1, electrical equipment insufficient oil, need to add oil, should be preferred to meet the relevant new oil standard, unused transformer oil. It is better to add the same oil base, the same brand and the same type of additive oil. The characteristics of the oil supplement shall be no less than the oil in the equipment. When the new oil added in small amount, such as less than 5%, usually do not have any problem; but if the adding amount of more new oil, do first sludge precipitation test should be fill in the confirmation before oil sludge precipitation, acid value, dielectric loss factor values is not greater than the oil in the equipment, can fill oil.

2、不同油基的油原则上不宜混合使用。

2, different oil-based oil, in principle, should not be mixed use.

在特殊情况下，如需将不同牌号的新油混合使用，应按混合油的实测凝点决定是否适于此地域的要求，然后进行混油试验，并且混合样品的结果应不比差的单个油样差。

In special circumstances, such as the new oil mixed with different grades, should according to the actual point of mixed oil to decide whether suitable for this region, then the oil blending test, and mixed samples results should not be the worst kind of oil than the individual difference.

如在运行油中混入不同牌号的新油或已使用过的油，除应事先测定混合油的凝点以外，还应进行老化试验和油泥试验，并观察油泥析出情况，无沉淀方可使用，所获得的混合样品的结果应不比原运行的油的差，才能决定可混合使用。

The new oil as in the operation of oil mixed with different brands or have used oil, in addition to the prior determination of mixed oil pour point outside, should also be aging test and sludge test, and observe the sludge precipitation, no precipitation can be used, the obtained results should not be mixed samples than the original running oil poor, can decide the mix.

对于进口油或产地、生产厂家来源不明的油，原则上不能与不同牌号的运行油混合使用，当必须混用时，应预先对混用前的油及混合后的油进行老化试验，在无油泥沉淀析出的情况下，混合油的质量应不低于原运行油时，方可混合使用；若相混的都是新油，其混合的质量应不低于差的一种油，并需要按实测凝点决定是否可以适于该地区使用。

For the imported oil or origin, manufacturer of unknown sources of oil, use can not be mixed with the oil of different grades of operation principle, when must mix, should advance to the mixed oil and mixed oil after aging test, in the case of no sludge precipitation, the quality of mixed oil should not be less than the original operation oil, can be mixed use; if the mix is the new oil, the mixed quality should not be less than one of the worst oil, and according to the actual need to decide whether the pour point can be adapted to the area to use.