HyVolt - Electrical Insulating Oil

Ergon’s HyVolt products are naphthenic insulating oils meeting the requirements of both IEC 60296 ed.5, 2020 general specifications and special applications and ASTM D3487-2016. HyVolt products have a very low pour point, excellent oxidation stability, and electrical properties making them suitable for the most demanding requirements set by leading global transformer manufacturers.


Electrical insulating oil / transformer oil for: power and distribution transformers, switchgear and circuit breakers.


Ergon’s HyVolt products fully meet the following international specifications:

  • IEC 60296 ed.5, 2020, general requirements and special applications, including full declaration of additives
  • ASTM D3487–16 including full declaration on additives per Section 4.4


  • Superior Oxidation Stability
    Low acid and sludge formation when tested to ASTM D2440 and IEC 61125
  • High Dielectric Strength
    Dielectric strength exceeding the most stringent international requirements
  • Excellent Cooling Properties
    Made from wax free naphthenic crude which gives a naturally low pour point (typical -64°C) without the use of a pour point depressant
  • Miscibility
    Ergon’s line of HyVolt Oils is fully miscible with insulating oils meeting the requirements set by IEC 60296 ed.5, 2020 and ASTM D3487-16


HyVolt I is un-inhibited, HyVolt II and III contain one antioxidant inhibitor, BHT, which is part of the approved list of inhibitors per ASTM D3487 and IEC 60296 and is detected per ASTM D2668. HyVolt products contain no other additives, such as those listed below:

  • PCB Free
    Tested as per IEC 61619:1997
  • DBDS Free
    Detection method using GC-AED
  • Passivator Free
    Tested as per IEC 60666:2010
  • Metal Deactivator Free
    Detection method using HPLC / GC-MS
  • Silicon Free

Production Technique

Ergon produces its insulating oils by distillation of virgin naphthenic crude followed by a modern, high pressure, severe hydrotreating process. All processes are closely monitored and final product is subject to approval from qualified personnel. No re-refined or reclaimed oils are used in Ergon’s production.