UL 845 PDF

1 Scope

1 1.1 This standard applies to motor control centers to be used in accordance with the U.S. National Electrical Code, ANSI/NFPA 70, CSA C22.1, Canadian Electrical Code, Part 1, and the Mexican Electrical Installations (Utility), NOM-001-SEDE.

1 1.2 These requirements cover motor control centers for use on circuits having available short-circuit currents 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 rated not more than 1000 V ac or dc.

1 1.4 Requirements for fire pump controllers are as provided in Annex C, item 11.

SUMMARY OF TOPICS

This revision of ANSI/UL 845 dated February 28, 2025 includes the following changes in requirements:

– Addition of Class CF; 9.3.6, 9.15.4.2, Annex C, and Annex D

– Calibration Performance; 8.3.2

– Contactor Overload Protection; 8.3.8

– Trip-out Performance of Circuit Breakers; 8.3.17.1.1, 8.3.17.1.2, and 8.3.17.1.3

– Correction in Conversion of HP to kW; Table 15, Table 16

– Short-time and Short-circuit Current Ratings of Motor Control Center Units; 5.4.1 (title), 5.4.1.4, 5.4.4.1, 5.4.4.2, Table 3, Table 45, 6.3.11A, 6.3.11B, 8.3.10A, 8.3.15A, 8.3.16A, Clause 9.10A, Clause 9.11A, Clause 9.15A, and Clause 9.16A

– Short Circuit Test Performance; 8.3.12 – 8.3.17, 8.3.22, 8.3.23, 9.12, 9.12.1.2, 9.12.3.8, Clauses 9.13 – 9.17, 9.16.1, Clauses 9.23 and 9.24