Univolt N 61 B

Electrical Insulating Oil

Univolt™ N 61B is a good quality, fully inhibited transformer oil designed to meet the operating requirements of transformers and other oil filled electrical equipment. It meets the requirements of ASTM D 3487 Type II fluid, providing good performance in transformers, circuit breakers, switches, and capacitors.


Equipment lubricant recommendations

Our Mobil Serv℠ Product Selector tool will help you identify lubricant(s) for your specific equipment.

Data sheets

Features and Benefits

Univolt N 61B is manufactured from carefully selected base stocks favored by the domestic power industry under stringently controlled manufacturing conditions. It meets the demanding requirements of the ANSI/ASTM D 3487 specification for electrical insulating oils.

•  Good Oxidation stability helps to extend lubricant service life and reduce maintenance costs

•  Great low temperature performance helps enable easy low temperature start up

•  Industry proven insulating properties



     •  Oil filled electrical equipment such as transformers, load tap chagers, switches, circuit breakers, high voltage capacitors, and lamp ballasts

     •  Some EDM (electrical discharge machines) as a coolant and insulator between charged electrodes

     •  Applications where a low viscosity mineral oil providing good low temperature properties is required


Specifications and Approvals

This product meets or exceeds the requirements of:

ASTM D 3487 Type II, (2000)


Properties and Specifications


Aniline Point, °C, ASTM D611


ASTM Color, ASTM D1500


Corrosive Sulfur, ASTM D1275B


Dielectric Strength @ 60 Hz, kV, ASTM D877


Flash Point, Cleveland Open Cup, °C, ASTM D92


Interfacial Tension @ 25 C, dynes/cm, ASTM D971


Kinematic Viscosity @ 100 C, mm2/s, ASTM D445


Kinematic Viscosity @ 40 C, mm2/s, ASTM D445


Neutralization Number, mgKOH/g, ASTM D974


Pour Point, °C, ASTM D97


Specific Gravity, 15.6 C/15.6 C, ASTM D1298


Water, ppm, ASTM D1533



Health and safety

Health and Safety recommendations for this product can be found on the Material Safety Data Sheet (MSDS) @ http://www.msds.exxonmobil.com/psims/psims.aspx