UL & NFPA Standards

UL & NFPA Standards

UL & NFPA Standards

USA UL and NFPA Standards for machineries

UL 891 is a tristandard. That means it is exacly the same content in the following three norms:
- CSA Group: CSA C22.2 No. 244-05
- Underwriters Laboratories Inc: UL 891
- Association of Standardization and Certification: NMX-J-118/2-ANCE-2012.

The subjects are the SWITCHBOARDS, also called in North America "dead-front switchboard". In Europe the equivalent standards are the EN 61439-1 and EN 61439-2. However the approach is different. EN 61439 puts a lot of emphasis on the Design Verification and cabinet testing. UL 891 is mainly about how to design the switchboard.

The Standard applies to switchboards nominally rated at 600 V or less and intended for use in accordance with the Canadian Electrical Code, Part 1 (CE Code, Part 1), the National Electrical Code (NEC), ANSI/NFPA 70, and the Mexican Standard for Electrical Installations (Utility), NOM-001-SEDE.
These requirements cover switchboards for use on circuits having available RMS symmetrical short-circuit currents of not more than 200 000 A.

NFPA 79
Industrial Machinery NFPA 79
In March 2018 the new edition of Industrial Machinery NFPA 79, the electrical standard for industrial machineries in the USA, was published. Although the standard has many parts in common with IEC 60204-1 (alignment started with 2002 edition), there are still several differences. Unlike IEC 60204-1, NFPA 79 does not recognize the advantage of class 2 insulated conductors, so the criteria for bonding metal parts is different. An excellent standard for bonding criteria is C22.2 No. 0.4 of 2017: Bonding of electrical equipment. Although it is a Canadian standard, the approach is the same in the
UL 891
UL 891: Switchboards
UL 891 is a Tristandard. That means it is exactly the same content in the following three norms: CSA Group: CSA C22.2 No. 244-05. Underwriters Laboratories Inc: UL 891. Association of Standardization and Certification: NMX-J-118/2-ANCE-2012. The subjects are the SWITCHBOARDS, also called in North America "dead-front switchboard". In Europe the equivalent standards are the EN 61439-1 and EN 61439-2. However the approach is different. EN 61439 puts a lot of emphasis on the Design Verification and cabinet testing. UL 891 is mainly about how to design the switchboard. The Standard applies
NFPA 70
NFPA 70: National Electrical Code
NFPA 70 or NATIONAL ELECTRICAL CODE is the reference standard for electrical installations in premises and buildings in USA.  The first National Electrical Code was developed in 1897. In 1911, the National Fire Protection Association (NFPA) became the sponsor, and the Code has been revised on numerous occasions since that date. Now it is revised every three years. The latest edition is 2020. The NEC is available for adoption as the electrical law in a governmental jurisdiction. That governmental jurisdiction may add one or more amendments to allow for local needs, preferences, or conditions (s
UL 508A
UL 508 A: Industrial Control Panels
UL 508A is the technical standard for the Industrial Control Panels in USA. Starting from the basics of electrical safety, stated by the NEC and looking at the prescriptions stated in NFPA 79, it gives indications for the design of industrial control panels. While the NFPA 79 provides prescriptions for industrial machinery control panels, UL508A has a bruader scope and it is focused on the criteria in order to design the control panel. In Europe, the equivalent standards are EN 61439 (for switchboards) and EN 60204-1 (for industrial control panels). The lastest release of this standard was