590 – Temporary Installations
590.4(G), Ex. No. 2 – Temporary Installations
Change at a Glance:
On construction sites, a new exception to 590.4(G) permits branch-circuits that are permanently installed in framed walls and ceilings to be used for temporary power or lighting (with GFCI protection).
590.4 General (Temporary Installations)
(G) Splices. A box, conduit body, or other enclosure, with a cover installed, shall be required for all splices except where:.
Exception No. 1: On construction sites, a box, conduit body, or other enclosure shall not be required for either of the following conditions:
(1) The circuit conductors being spliced are all from nonmetallic multiconductor cord or cable assemblies, provided that the equipment grounding continuity is maintained with or without the box.
(2) The circuit conductors being spliced are all from metal-sheathed cable assemblies terminated in listed fittings that mechanically secure the cable sheath to maintain effective electrical continuity.
Exception No. 2: On construction sites, where permanent wiring in framed walls and ceilings is GFCI protected and used to supply temporary power or lighting:
(1) A cover shall not be required for splices installed completely inside of junction boxes with plaster rings.
(2) Listed pigtail-type lampholders shall be permitted to be installed in ceiling-mounted junction boxes with plaster rings.
(3) Finger safe devices for supplying and connection to devices shall also be permitted.
590.8 – Overcurrent Protective Devices in Temporary Installations
Change at a Glance:
A new section was added to provide guidance for the AHJ in the reuse of overcurrent protective devices in temporary installations and the use of current limiting overcurrent protective devices required for solidly grounded wye electrical services of more than 150 volts to ground but not exceeding 1000 volts phase-to-phase in temporary installations.
590.8 Overcurrent Protective Devices. (Temporary Installations)
(A) Where Reused. Where overcurrent protective devices that have been previously used are installed in a temporary installation, these overcurrent protective devices shall be examined to ensure these devices have been properly installed, properly maintained, and there is no evidence of impending failure.
(B) Service Overcurrent Protective Devices. Overcurrent protective devices for solidly grounded wye electrical services of more than 150 volts to ground but not exceeding 1000 volts phase-tophase shall be current limiting.
Informational Note: The phrase “evidence of impending failure” means that there is evidence such as arcing, overheating, loose or bound equipment parts, visible damage, or deterioration. The phrase “properly maintained” means that the equipment has been maintained in accordance with the manufacturers’ recommendations and applicable industry codes and standards. References for manufacturers’ recommendations and applicable industry codes and standards include but are not limited to NEMA AB 4-2017, Guidelines for Inspection and Preventative Maintenance of Molded- Case Circuit Breakers Used in Commercial and Industrial Applications; NFPA 70B-2019, Recommended Practice for Electrical Equipment Maintenance; NEMA GD 1-2016, Evaluating Water-Damaged Electrical Equipment; and IEEE 1458-2017, IEEE Recommended Practice for the Selection, Field Testing, and Life Expectancy of Molded-Case Circuit Breakers for Industrial Applications.