Paraffinic Transformer Oils for use at Low Temperatures

The influence of linear paraffins on the behavior of paraffinic transformer oils at low temperatures has been studied here using urea and thiourea adduction as a dewaxing method. It was found that pourdepressant additives are no longer effective when the linear paraffin content is above a critical value which depends on the average melting temperature of the linear paraffins. On the basis of these observations, guidelines are given for the selection of new commercial paraffinic transformer oils for use at low temperatures.