Mobil Industrial, United States

Electrical Insulating Oil

Product Description

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.


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 chargers, 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

Univolt N 61 B meets or exceed the requirements of: 
ASTM D 3487 Type II (2000) 


Typical Properties

Univolt N 61 B 
Viscosity, cSt, 40C, ASTM D 4459.2
Viscosity, cSt, 100C, ASTM D 4452.3
Aniline Point, C, ASTM D 61175.8
Color, ASTM D 1500L0.5
Corrosive Sulfur, ASTM D 1275noncorrosive
Pour Point, C, ASTM D 97-50
Flash Point, C, ASTM D 92151
Specific Gravity, D 12980.91
Interfacial Tension, 25C, dynes/cm, ASTM D 97148
Neutralization Number, mg KOH/g, ASTM D 9740.013
Water, ppm, ASTM D 153335
Dielectric Strength, kV, ASTM D 87730


Health and Safety

Refer to the Material Safety Data Sheet for safety and health information.
Material Safety Data Sheets can be obtained from your local distributor; via the Internet on http://www.msds.exxonmobil.com.

All trademarks used herein are trademarks or registered trademarks of Exxon Mobil Corporation or one of its subsidiaries unless indicated otherwise.


Exxon Mobil Corporation
22777 Springwoods Village Parkway
Spring TX 77389

1-800-ASK MOBIL (275-6624)

Typical Properties are typical of those obtained with normal production tolerance and do not constitute a specification. Variations that do not affect product performance are to be expected during normal manufacture and at different blending locations. The information contained herein is subject to change without notice. All products may not be available locally. For more information, contact your local ExxonMobil contact or visit www.exxonmobil.com
ExxonMobil is comprised of numerous affiliates and subsidiaries, many with names that include Esso, Mobil, or ExxonMobil. Nothing in this document is intended to override or supersede the corporate separateness of local entities. Responsibility for local action and accountability remains with the local ExxonMobil-affiliate entities.