UL 489A:2013 free download

UL 489A:2013 free download Circuit Breakers for Use in Communications Equipment
1 Scope
1.1 The requirements of this standard cover single pole or multi-pole DC rated circuit breakers intendedfor use as branch circuit overcurrent and short-circuit protection in communications equipment.
1.2 All poles of mult-pole circuit breakers covered by this standard operate at the same potential.1.3 The requirements of this standard cover devices rated 600 volts DC or less.
1.4 This standard is intended to be used with the Standard for Molded-Case Circuit Breakers,Molded-Case Switches and Circuit-Breaker Enclosures, UL 489,as the requirements of this standardmodify tests described in that standard.
1.5 Unless otherwise specified，when the term “circuit breaker”is used in this standard, it refers to acircuit breaker intended for use with communications equipment.
2 Components
2.1 Except as indicated in 2.2, a component of a product covered by this standard shall comply with therequirements for that component.See Appendix A of the Standard for Molded-Case Circuit Breakers,Molded-Case Switches and Circuit-Breaker Enclosures, UL 489, for a list of standards coveringcomponents generally used in the products covered by this standard.
2.2 A component is not required to comply with a specific requirement that:
a) Involves a feature or characteristic not required in the application of the component in theproduct covered by this standard, or
b) ls superceded by a requirement in this standard.
2.3 A component shall be used in accordance with its rating established for the intended conditions ofuse.
2.4 Specific components are incomplete in construction features or restricted in performance capabilities.Such components are intended for use only under limited conditions, such as certain temperatures notexceeding specified limits,and shall be used only under those specific conditions.
3 Undated References
3.1 Any undated reference to a code or standard appearing in the requirements of this standard shall be interpreted as referring to the latest edition of that code or standard. CONSTRUCTION 4 General
4.1 A circuit breaker intended for use with communications equipment shall comply with the construction requirements for circuit breakers in the Standard for Molded-Case Circuit Breakers, Molded-Case Switches, and Circuit-Breaker Enclosures, UL 489, except as described in Sections 5 – 7.
5 Spacings
5.1 Spacings within a circuit breaker shall comply with the requirements in the Standard for Molded-Case Circuit Breakers, Molded-Case Switches, and Circuit-Breaker Enclosures, UL 489. When installed, only the spacings of the end-product need be met.
5.2 Spacings at terminals between the primary circuit and an auxiliary circuit shall meet the requirements of the Standard for Molded-Case Circuit Breakers, Molded-Case Switches, and Circuit-Breaker Enclosures, UL 489, unless the circuit breaker is marked in accordance with 1 6.5.
6 Terminals
6.1 A circuit breaker shall have a wire connector, wire-binding screw, a stud-type terminal, or a spring-action terminal formed to mate with end-product parts, for making electrical connections to the equipment with which it is intended to be used. 7 Manual ON/OFF Operation 7.1 A circuit breaker shall be able to be switched ON and OFF manually. An operation that requires the use of an ordinary tool is considered to be a manual operation.