UL1446 New Requirements effective on March 12, 1999

UL1446 New Requirements effective on March 12,1999

Review of Component - Systems, Electrical Insulation for Compliance with the
new requirements of UL1446 to become effective on March 12, 1999.

The following is a brief summary of new and revised paragraphs in the Fourth Edition of the Standard for Systems of Insulating Materials - General, UL1446, which have future effective dates indicated below and the action that may be required to determine compliance.

General Subject and Comment

<1> All insulation files will be revised to indicate that bobbins molded from polymeric materials shall comply with the Standard for Polymeric Materials - Fabricated Parts, UL746D, and, if molded off-site, the use of a Recognized Molder (QMMY2) is mandatory. (Effective March 12, 1997)

<2> Varnishes added to insulation systems that did not incorporate a varnish during the original aging of the system, shall have twisted pair thermal classes on those magnet wires aged in the insulation system of no more than one thermal class below that of the wire's thermal class (Effective March 12, 1999)

<3> Encapsulants, ground or interwinding insulations that were not thermally aged when the original insulation system was evaluated, shall comply with the requirements in Section 6.2. Depending on the differences between these components and those originally aged in the insulation system, either no additional testing is required or one temperature, two temperature or three temperature thermal agings may be necessary. (Effective March 12, 1999)

<4> Recognized magnet wires will need to comply with the heat shock requirement per ANSI/NEMA MW1000-93 or for those magnet wires that are not presently defined by this Standard shall comply with the heat shock requirement at 20 degrees C higher than the wire's thermal class (effective March 12, 1999)

<5> For winding wire not of the type cover by ANSI/NEMA MW1000-1993, such as filament windings, the insulation system including this type of wire shall have been subjected to a minimum three temperature thermal aging test program with this wire evaluated as turn-to-turn and if appropriate based on the use winding-to-ground or winding-to-winding insulation. (effective March 12, 1999)


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