Impedance Protected Motors

UL 1004-2

1 Scope

1.1 This Standard is intended to be read together with the Standard for Rotating Electrical Machines - General Requirements, UL 1004-1. The numbering of the Sections in this Standard corresponds to the like numbered Sections in UL 1004-1. The numbering of the paragraphs are unique to this Standard, and do not directly correspond to the like numbered paragraphs in 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. For Sections not shown, refer to the Standard for Rotating Electrical Machines - General Requirements, UL 1004-1.

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

1.3 This Standard applies to motors rated 600 volts or less.

1.4 This Standard does not apply to:

a) Motors employing a device that serves as a motor protector and a manual motor controller;

b) Motors employing a motor protector with contacts that control a relay coil in a motor starter;

c) Sealed (hermetic) type compressor motors; or

d) Impedance protected motors employing an automatic starting switch.