UL 845 STANDARD FOR SAFETY Motor Control Centers
1 Scope
1.1Products covered
1.1.1 This standard applies to motor control centers to be used in accordance with the U.S. NationalElectrical Code,ANSI/NFPA 70,CSA C22.1, Canadian Electrical Code, Part 1, and the Mexican Electricallnstallations (Utility),NOM-001-SEDE.
1.1.2 These requirements cover motor control centers for use on circuits having available short-circuitcurrents not more than 200 000 A rms symmetrical or 200 000 A dc.
1.1.3 This standard applies to single- and three-phase 50 and 60 Hz and dc motor control centers ratednot more than 1000 V ac or dc.
1.1.4 Requirements for fire pump controllers are as provided in Annex C, item 11.1.2Products not covered
These requirements do not cover switchboards or panelboards intended for the control of electric light andpower circuits, nor do they cover an individual unit for this purpose.Such units, however,that consist ofmanually or automatically operated switches, branch-circuit or service-circuit circuit-breakers, overcurrent-protective devices, or the like may be used within a motor control center.
1.3Equipment
1.3.1 A motor control center can contain, but is not limited to, any combination of equipment such as thefollowing:
a) full-voltage reversing or non-reversing combination motor control units;
b) full-voltage multispeed combination motor control units;
c) reduced-voltage part-winding, wye-delta or auto-transformer combination motor control units;
d) solid-state industrial controllers, such as adjustable-speed drives, programmable controllers,protective relays, and the like;
e) lighting or distribution panelboards;f) feeder-tap units;文章源自标准下载网-https://www.biao-zhun.cn/119151.html
