UFC 3 -520-01
June 10, 2002
8-22.214.171.124 In locations where electric equipment can be exposed to physical damage,
enclosures or guards must be so arranged and of such strength as to prevent such
8-126.96.36.199 Mark entrances to rooms and other guarded locations contai ning exposed
live parts with conspicuous warning signs forbidding unqualified persons to enter.
Equipment Rated Above 600 Volts. Provide equipment rated above 600
volts with clearances for safe operation and maintenance in accordance with OSHA
Standard 29 CFR 1910.303, Section h; the NESC, Section 12; and NFPA 70E, Section
Select equipment enclosures to provide the following:
To protect facility personnel from coming in contact with live parts.
To protect the equipment as necessary.
NEMA classifies enclosures based on the degree of protection provided by
the enclosure and the environmental conditions to which the enclosure will be exposed.
Table 8 -2 summarizes the NEMA enclosure types. For additional informati on, refer to
NEMA 250, Enclosures for Electrical Equipment (1000 Volts Maximum). If needed,
contact the enclosure manufacturer to determine the closest International
Electrotechnical Commission ( IEC) equivalent designation (NEMA 250, Appendix A,
also provides limited information).