NEMA SG 10
Guide to OSHA and NFPA 70E Safety Requirements When Servicing and Maintaining Medium-Voltage Switchgear, Circuit Breakers, and Medium-Voltage Controllers Rated above 1000 V
|Publication Date:||1 January 2019|
The main objective of this guide is to enhance electrical safety awareness and mitigate electrical hazards to Members of the workforce assigned to servicing and maintaining switchgear, owners, and users of the equipment, and the public. The goal of this guide is to ensure the adoption of OSHA and NFPA 70E safety-related practices for electrical work and requirements of electrical safety.
Provisions contained herein are applicable to all Members of the workforce who are engaged in testing, servicing, maintaining, and decommissioning switchgear, circuit breakers, and controllers rated above 1000 V.
This guide emphasizes OSHA and NFPA 70E safety requirements when servicing and maintaining equipment covered in, but not limited to, the following Standards:
a. Medium-voltage metal-clad switchgear assemblies (rated 1000 through 38,000 V) in accordance with ANSI/IEEE C37.20.2, Standard for Metal-Clad Switchgear
b. Medium-voltage metal-enclosed switchgear assemblies (rated 1000 through 38,000 V) in accordance with ANSI/IEEE C37.20.3, Standard for Metal-Enclosed Interrupter Switchgear
c. Circuit breakers rated above 1000 V in accordance with ANSI/IEEE C37.04, Standard Rating Structure for AC High-Voltage Circuit Breakers
d. Medium-voltage controllers in accordance with UL 347, Medium-Voltage AC Contactors, Controllers, and Control Centers
e. Medium-voltage pad-mounted switchgear (rated 1,000 through 38,000 V) in accordance with IEEE C37.74, Standard Requirements for Subsurface, Vault, and Pad-Mounted Load-Interrupter Switchgear and Fused Load-Interrupter Switchgear for Alternating Current Systems Up to 38 kV.
f. C37.60, IEEE/IEC International Standard-High-voltag
For convenience, this equipment will be called switchgear assemblies. Switchgear assemblies and controller assemblies may contain but are not limited to devices such as power circuit breakers, contactors, interrupter switches, selector switches, power fuses, controls, instrumentation, metering, and other protective equipment. These assemblies may be part of unit substations.
The provisions of the National Electric Code® (NEC), Standard for Electrical Safety in the Workplace, NFPA 70E, National Electric Safety Code (NESC), and OSHA Standards contained in this guide should be complied with at all user-controlled premises. These guidelines have specific requirements that apply to installations, servicing, and maintaining switchgear regardless of when they were designed or installed and are considered essential for ensuring workplace safety.