UL 1004-2 – Impedance Protected Motors

Please note: All interim revisions for this edition available at time of your purchase will be included.

UL 1004-2 is intended to be read together with the Standard for Rotating Electrical Machines – General Requirements, UL 1004-1. The requirements in this Standard supplement or amend the requirements in UL 1004-1. The requirements of UL 1004-1 apply unless modified by this Standard.

This Standard applies to motors that rely solely upon the impedance of the motor windings to prevent overheating.

This Standard applies to motors rated 600 volts or less.

This Standard does not apply to:

Motors employing a device that serves as a motor protector and a manual motor controller;
Motors employing a motor protector with contacts that control a relay coil in a motor starter;
Sealed (hermetic) type compressor motors; or
Impedance protected motors employing an automatic starting switch.