---
aliases:
  - nec-590
title: Article 590 Temporary Installations
tags:
  - authorship/other
  - destiny/uncertain
  - exclude-from-word-count
  - status/draft
  - topic/construction/electrical
  - type/media/reference
---
# Article 590 Temporary Installations

### 590.1 Scope.

The provisions of this article apply to temporary electric power and lighting installations.

### 590.2 All Wiring Installations.

#### 590.2(A) Other Articles.

Except as specifically modified in this article, all other requirements of this Code for permanent wiring shall apply to temporary wiring installations.

#### 590.2(B) Approval.

Temporary wiring methods shall be acceptable only if approved based on the conditions of use and any special requirements of the temporary installation.

### 590.3 Time Constraints.

#### 590.3(A) During the Period of Construction.

Temporary electric power and lighting installations shall be permitted during the period of construction, remodeling, maintenance, repair, or demolition of buildings, structures, equipment, or similar activities.

#### 590.3(B) 90 Days.

Temporary electric power and lighting installations shall be permitted for a period not to exceed 90 days for holiday decorative lighting and similar purposes.

#### 590.3(C) Emergencies and Tests.

Temporary electric power and lighting installations shall be permitted during emergencies and for tests, experiments, and developmental work.

#### 590.3(D) Removal.

Temporary wiring shall be removed immediately upon completion of construction or purpose for which the wiring was installed.

### 590.4 General.

#### 590.4(A) Services.

Services shall be installed in conformance with Parts I through VIII of Article 230, as applicable.

#### 590.4(B) Feeders.

Overcurrent protection shall be provided in accordance with 240.4, 240.5, 240.100, and 240.101. Conductors shall be permitted within cable assemblies or within multiconductor cords or cables of a type identified in Table 400.4 for hard usage or extra-hard usage. For the purpose of this section, the following wiring methods shall be permitted:

* (1) Type NM, Type NMC, and Type SE cables shall be permitted to be used in any dwelling, building, or structure without any height
 limitation or limitation by building construction type and without concealment within walls, floors, or ceilings.

* (2) Type SE cable shall be permitted to be installed in a raceway in an underground installation.

> [!important] Exception:
> Single insulated conductors shall be permitted where installed for the purpose(s) specified in 590.3(C), where accessible only to qualified persons.

#### 590.4(C) Branch Circuits.

All branch circuits shall originate in an approved power outlet, switchgear, switchboard or panelboard, motor control center, or fused switch enclosure. Conductors shall be permitted within cable assemblies or within multiconductor cord or cable of a type identified in Table 400.4 for hard usage or extra-hard usage. Conductors shall be protected from overcurrent as provided in 240.4, 240.5, and 240.100. For the purposes of this section, the following wiring methods shall be permitted:

* (1) Type NM, Type NMC, and Type SE cables shall be permitted to be used in any dwelling, building, or structure without any height limitation or limitation by building construction type and without concealment within walls, floors, or ceilings.

* (2) Type SE cable shall be permitted to be installed in a raceway in an underground installation.

> [!important] Exception:
> Branch circuits installed for the purposes specified in 590.3(B) or 590.3(C) shall be permitted to be run as single insulated conductors. Where the wiring is installed in accordance with 590.3(B), the voltage to ground shall not exceed 150 volts, the wiring shall not be subject to physical damage, and the conductors shall be supported on insulators at intervals of not more than 3.0 m (10 ft); or, for festoon lighting, the conductors shall be so arranged that excessive strain is not transmitted to the lampholders.

#### 590.4(D) Receptacles.

##### 590.4(D)(1) All Receptacles.

All receptacles shall be of the grounding type. Unless installed in a continuous metal raceway that qualifies as an equipment grounding conductor in accordance with 250.118 or a continuous metal-covered cable that qualifies as an equipment grounding conductor in accordance with 250.118, all branch circuits shall include a separate equipment grounding conductor, and all receptacles shall be electrically connected to the equipment grounding conductor(s). Receptacles on construction sites shall not be installed on any branch circuit that supplies temporary lighting.

##### 590.4(D)(2) Receptacles in Wet Locations.

All 15- and 20-ampere, 125- and 250-volt receptacles installed in a wet location shall comply with 406.9(B)(1).

#### 590.4(E) Disconnecting Means.

Suitable disconnecting switches or plug connectors shall be installed to permit the disconnection of all ungrounded conductors of each temporary circuit. Multiwire branch circuits shall be provided with a means to disconnect simultaneously all ungrounded conductors at the power outlet or panelboard where the branch circuit originated. Identified handle ties shall be permitted.

#### 590.4(F) Lamp Protection.

All lamps for general illumination shall be protected from accidental contact or breakage by a suitable luminaire or lampholder with a guard.

Brass shell, paper-lined sockets, or other metal-cased sockets shall not be used unless the shell is connected to the circuit equipment grounding conductor.

#### 590.4(G) Splices.

A box, conduit body, or other enclosure, with a cover installed, shall be required for all splices.

> [!important] 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.

> [!important] Exception No. 2:
> On construction sites, branch-circuits that are permanently installed in framed walls and ceilings and are used to supply temporary power or lighting, and that are GFCI protected, the following shall be permitted:
>
> * (1) A box 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 shall be permitted for supplying and connection of devices.

#### 590.4(H) Protection from Accidental Damage.

Flexible cords and cables shall be protected from accidental damage. Sharp corners and projections shall be avoided. Where passing through doorways or other pinch points, protection shall be provided to avoid damage.

#### 590.4(I) Termination(s) at Devices.

Flexible cords and cables entering enclosures containing devices requiring termination shall be secured to the box with fittings listed for connecting flexible cords and cables to boxes designed for the purpose.

#### 590.4(J) Support.

Cable assemblies and flexible cords and cables shall be supported in place at intervals that ensure that they will be protected from physical damage. Support shall be in the form of staples, cable ties, straps, or similar type fittings installed so as not to cause damage.

Cable assemblies and flexible cords and cables installed as branch circuits or feeders
shall not be installed on the floor or on the ground.
Extension cords shall not be required to comply with 590.4(J).
Vegetation shall not be used for support of overhead spans of branch circuits or feeders.

> [!important] Exception:
> For holiday lighting in accordance with 590.3(B), where the conductors or cables are arranged with strain relief devices, tension take-up devices, or other approved means to avoid damage from the movement of the live vegetation, trees shall be permitted to be used for support of overhead spans of branch-circuit conductors or cables.

### 590.5 Listing of Decorative Lighting.

Decorative lighting used for holiday lighting and similar purposes,
in accordance with 590.3(B),
shall be listed and shall be labeled on the product.

### 590.6 Ground-Fault Protection for Personnel.

Ground-fault protection for personnel for all temporary wiring installations shall be provided to comply with 590.6(A) and (B). This section shall apply only to temporary wiring installations used to supply temporary power to equipment used by personnel during construction, remodeling, maintenance, repair, or demolition of buildings, structures, equipment, or similar activities. This section shall apply to power derived from an electric utility company or from an on-site-generated power source.

#### 590.6(A) Receptacle Outlets.

Temporary receptacle installations used to supply temporary power to equipment used by personnel during construction, remodeling, maintenance, repair, or demolition of buildings, structures, equipment, or similar activities shall comply with the requirements of 590.6(A)(1) through (A)(3), as applicable.

> [!important] Exception:
> In industrial establishments only, where conditions of maintenance and supervision ensure that only qualified personnel are involved, an assured equipment grounding conductor program as specified in 590.6(B)(2) shall be permitted for only those receptacle outlets used to supply equipment that would create a greater hazard if power were interrupted or having a design that is not compatible with GFCI protection.

##### 590.6(A)(1) Receptacle Outlets Not Part of Permanent Wiring.

All 125-volt, single-phase, 15-, 20-, and 30-ampere receptacle outlets that are not a part of the permanent wiring of the building or structure and that are in use by personnel shall have ground-fault circuit-interrupter protection for personnel. In addition to this required ground-fault circuit-interrupter protection for personnel, listed cord sets or devices incorporating listed ground-fault circuit-interrupter protection for personnel identified for portable use shall be permitted.

##### 590.6(A)(2) Receptacle Outlets Existing or Installed as Permanent Wiring.

Ground-fault circuit-interrupter protection for personnel shall be provided for all 125-volt, single-phase, 15-, 20-, and 30-ampere receptacle outlets installed or existing as part of the permanent wiring of the building or structure and used for temporary electric power.

Listed cord sets or devices incorporating listed ground-fault circuit-interrupter protection for personnel identified for portable use shall be permitted.

##### 590.6(A)(3) Receptacles on 15-kW or less Portable Generators.

All 125-volt and 125/250-volt, single-phase, 15-, 20-, and 30-ampere receptacle outlets that are a part of a 15-kW or smaller portable generator shall have listed ground-fault circuit-interrupter protection for personnel. All 15- and 20-ampere, 125- and 250-volt receptacles, including those that are part of a portable generator, used in a damp or wet location shall comply with 406.9(A) and (B).

Listed cord sets or devices incorporating listed ground-fault circuit-interrupter protection for personnel identified for portable use shall be permitted for use with 15-kW or less portable generators manufactured or remanufactured prior to January 1, 2011.

#### 590.6(B) Other Receptacle Outlets.

For temporary wiring installations, receptacles, other than those covered by 590.6(A)(1) through (A)(3) used to supply temporary power to equipment used by personnel during construction, remodeling, maintenance, repair, or demolition of buildings, structures, or equipment, or similar activities, shall have protection in accordance with 590.6(B)(1) or the assured equipment grounding conductor program in accordance with 590.6(B)(2).

##### 590.6(B)(1) GFCI Protection.

Ground-fault circuit-interrupter protection for personnel.

##### 590.6(B)(2) Assured Equipment Grounding Conductor Program.

A written assured equipment grounding conductor program continuously enforced at the site by one or more designated persons to ensure that equipment grounding conductors for all cord sets, receptacles that are not a part of the permanent wiring of the building or structure, and equipment connected by cord and plug are installed and maintained in accordance with the applicable requirements of 250.114, 250.138, 406.4(C), and 590.4(D).

* (a) The following tests shall be performed on all cord sets, receptacles that are not part of the permanent wiring of the building or structure, and cord-and-plug-connected equipment required to be connected to an equipment grounding conductor:

    * (1) All equipment grounding conductors shall be tested for continuity and shall be electrically continuous.

    * (2) Each receptacle and attachment plug shall be tested for correct attachment of the equipment grounding conductor. The equipment grounding conductor shall be connected to its proper terminal.

    * (3) All required tests shall be performed as follows:

        * a. Before first use on site
        * b. When there is evidence of damage
        * c. Before equipment is returned to service following any repairs
        * d. At intervals not exceeding 3 months

* (b) The tests required in 590.6(B)(2)(a) shall be recorded and made available to the authority having jurisdiction.

The assured equipment grounding conductor program shall be documented and made available to the authority having jurisdiction.

> [!info] Informational Note:
> The Occupational Safety and Health Administration 29 CFR 1910 and 1926 contain requirements for assured equipment grounding conductor programs. Additional information is provided in NFPA 70E-2018, Standard for Electrical Safety in the Workplace.

### 590.7 Guarding.

For wiring over 600 volts, nominal, suitable fencing, barriers, or other effective means shall be provided to limit access only to authorized and qualified personnel.

### 590.8 Overcurrent Protective Devices.

#### 590.8(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.

#### 590.8(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-to-phase shall be current limiting.

> [!info] 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.
