UL 1446 - Standard for Systems of Insulating Materials

What is UL1446?

UL1446 is the Standard for Safety of Electrical Insulating System established by the Underwritier Labortary(UL). The recognition of a system by UL requires that the system go through 5000 hrs of heat aging at the lowest of the three or four temperatures the system is tested at.

What is an electrical insulation system (EIS)?

Electrical insulation system is an unique intimate combination of two or more insulating materials(EIM) used in electrical equipments like motors, transformers and relays.

How can I use a pre-approved system from component manufacturers?

Step 1 : Identify the desired thermal class and voltage:

  • Class E (120℃)
  • Class B (130℃)
  • Class F (155℃)
  • Class N (200℃)
  • Class R (220℃)
  • Class S (240℃)

Step 2 : Fax your material list to us. We will find a suitable system for you.

Step 3 : Complete the authorization request form and fax it back to us.

Step 4 : We prepare all other required documents and send them to UL.

Step 5 : Wait for the approval from UL.

What is Sealed Tube Testing?

Sealed Tube Testing is a short-term test program involving a two week oven conditioning period. This test is used to evaluate the chemical compatibility of any minor insulating components that are added to an existing insulation system.