Abstract <p>The main factors that affect the degree of cross linking of peroxide cross-linked polyethylene insulation in medium- and high-voltage cables have been considered. The vulcanization properties necessary to calculate the degree of cross linking have been determined by a rotational rheometer study. Based on the axisymmetric mathematical model of peroxide cross linking in the ANSYS Fluent package, the temperature dependences have been obtained to calculate the final degree of insulation cross linking. The influence of geometric dimensions of the insulated core, as well as of other process parameters, such as line speed and temperature, on the quality of the resulting insulation has been determined. Conclusions regarding the significant and minor factors that affect the quality of high-voltage cable products have been drawn.</p>