NEMA Publishes Panelboard, Distribution Standards - NEMA PB 1.1, NEMA PB 2.1

March 28, 2008 // Published as a news service by IHS

Both were developed by the Panelboard and Distribution Board Product Group of the Low Voltage Distribution Equipment (LVDE) Section.

ANSI/NEMA PB 1.1-2007 is a guide to the best practices for the handling, storage, installation, operation and maintenance of panelboards. It covers single panelboards or groups of panel units suitable for assembly in the form of single panelboards, including buses, and with or without switches or automatic overload protective devices (fuses or circuit breakers) or both.

These units are used in the distribution of electricity at 600 volts and less with 1600-ampere mains or less, and 1200-ampere branch circuits or less.

Specifically excluded are live-front panelboards, panelboards employing cast enclosures for special service conditions and panelboards designed primarily for residential and light commercial service equipment.

ANSI/NEMA PB 2.1-2007 provides the same guidance for deadfront distribution switchboards and covers floor-mounted deadfront switchboards that consist of an enclosure; molded case and low-voltage power circuit breakers; fusible or non-fusible switches; instruments; and metering, monitoring or control equipment, with associated interconnections and supporting structures.

These units are used in the distribution of electricity at 600 volts and less, and 6000 amperes or less.

According to NEMA, these standards do not claim to cover all details or variations in equipment, nor do they provide for every possible contingency regarding installation, operation or maintenance. The work described in the documents should be performed only by qualified personnel familiar with the construction and operation of panelboards.

Source: National Electrical Manufacturers Association (NEMA).