10.1 Purpose and Scope of Application
10.1.1 This Regulatory Standard (NR) establishes the minimum requirements and conditions aimed at the implementation of control measures and preventive systems, to ensure the safety and health of workers who directly or indirectly interact with electrical installations and services.
10.1.2 This NR applies to the phases of power generation, transmission, distribution and consumption, including the design, construction, assembly, operation and maintenance stages of electrical installations, as well as any work carried out in their vicinity. It shall comply with official technical standards set by competent bodies, and in the absence or omission of such standards, applicable international standards shall be adopted.
10.2 Control Measures
10.2.1 In all interventions on electrical installations, preventive measures shall be adopted to control electrical risks and other additional hazards, using risk analysis techniques, so as to guarantee occupational safety and health.
10.2.2 The adopted control measures shall be integrated with the company's other initiatives for the preservation of workplace safety, health and environment.
10.2.3 Companies are required to keep updated single-line diagrams of the electrical installations of their premises, containing the specifications of the grounding system and other protective equipment and devices.
10.2.4 Establishments with an installed load exceeding 75 kW must set up and maintain the Electrical Installation Record, containing, in addition to the provisions of subitem 10.2.3, at least:
a) set of technical and administrative safety and health procedures and instructions implemented in compliance with this NR, plus a description of existing control measures;
b) documentation of inspections and measurements of the lightning protection system and electrical grounding systems;
c) specifications for collective and individual protective equipment and tools applicable as required by this NR.
d) supporting documentation on workers' qualification, competency, training, authorization and records of completed training courses;
e) electrical insulation test results for personal and collective protective equipment;
f) certifications of electrical equipment and materials used in classified hazardous areas;
g) updated technical inspection report with recommendations and adjustment schedules, covering items "a" to "f".
10.2.5 Companies that operate installations or equipment integrated into the electric power system shall prepare a record containing the content of item 10.2.4 and add the following documents to the record:
a) description of emergency procedures;
b) certifications of collective protection equipment and personal protection equipment.
10.2.5.1 Companies that perform work in the vicinity of the Electric Power System shall prepare a record covering items "a", "c", "d" and "e" of item 10.2.4 and items "a" and "b" of item 10.2.5.
10.2.6 The Electrical Installation Record shall be organized and kept updated by the employer or a person formally designated by the company, and shall be available to workers involved in electrical installations and services.
10.2.7 The technical documents provided for in the Electrical Installation Record shall be prepared by a legally qualified professional.
10.2.8 Collective Protection Measures
10.2.8.1 In all services performed on electrical installations, applicable collective protection measures shall be previously planned and adopted with priority, through procedures suitable for the activities to be carried out, in order to guarantee the safety and health of workers.
10.2.8.2 Collective protection measures shall firstly comprise electrical de-energization as established in this NR and, when not feasible, the use of safety voltage.
10.2.8.2.1 When it is impossible to implement the provisions of subitem 10.2.8.2, other collective protection measures shall be used, such as: insulation of live parts, obstacles, barriers, signage, automatic supply disconnection system, automatic reclosing blocking.
10.2.8.3 The grounding of electrical installations shall be carried out in accordance with the regulations established by competent bodies and, in the absence thereof, shall comply with the applicable International Standards.
10.2.9 Individual Protection Measures
10.2.9.1 In work on electrical installations, when collective protection measures are technically unfeasible or insufficient to control risks, specific personal protective equipment suitable for the performed activities shall be adopted, in compliance with the provisions of NR 6.
10.2.9.2 Work clothing shall be suitable for the activities, taking into account conductivity, flammability and electromagnetic influences.
10.2.9.3 The use of personal ornaments is prohibited during work on electrical installations or in their vicinity.
10.3 Safety in Projects
10.3.1 Electrical installation projects are required to specify circuit disconnect devices with features to prevent re-energization and warning signage indicating operational status.
10.3.2 The electrical project shall, whenever possible, provide for the installation of simultaneous-action sectionalizing devices allowing the implementation of circuit re-energization blocking.
10.3.3 The design of electrical installations shall consider safe spacing regarding the sizing and location of its components and external influences during operation, construction and maintenance services.
10.3.3.1 Electrical circuits for different purposes, such as communication, signaling, control and electric traction, shall be identified and installed separately, except when technological development allows sharing, in compliance with project definitions.
10.3.4 The project shall define the configuration of the grounding scheme, the requirement for interconnection between the neutral conductor and the protection conductor, and the grounding of conductive parts not intended for conducting electricity.
10.3.5 Whenever technically feasible and necessary, sectionalizing devices shall be designed with fixed built-in features for equipotential bonding and grounding of the sectionalized circuit.
10.3.6 Every project shall provide conditions for the adoption of temporary grounding.
10.3.7 The design of electrical installations shall be available to authorized workers, competent authorities and other persons authorized by the company, and shall be kept updated.
10.3.8 The electrical project shall comply with the provisions of the Regulatory Standards for Occupational Health and Safety and established official technical regulations, and shall be signed by a legally qualified professional.
10.3.9 The project descriptive report shall contain at least the following safety items:
a) specification of characteristics related to protection against electric shock, burns and other additional risks;
b) indication of the position of electrical circuit operating devices: (Green – D, off and Red – L, on);
c) description of the identification system for electrical circuits and equipment, including operating, control, protection and interlocking devices, conductors, equipment and structures themselves, defining how such markings shall be physically applied to installation components;
d) recommendations for restrictions and warnings regarding personnel access to installation components;
e) applicable precautions against external influences;
f) functional principle of the protective devices contained in the project intended for people safety;
g) description of the compatibility of protective devices with the electrical installation.
10.3.10 Projects shall ensure that installations provide workers with adequate lighting and a safe working position, in accordance with NR 17 - Ergonomics.
10.4 Safety in Construction, Assembly, Operation and Maintenance
10.4.1 Electrical installations shall be constructed, assembled, operated, renovated, expanded, repaired and inspected in order to guarantee the safety and health of workers and users, and shall be supervised by an authorized professional in accordance with this NR.
10.4.2 Preventive measures shall be adopted in the aforementioned works and activities to control additional risks, especially regarding height, confinement, electric and magnetic fields, explosiveness, humidity, dust, fauna and flora and other aggravating factors, with the use of safety signage.
10.4.3 Only electrical equipment, devices and tools compatible with the existing electrical installation may be used in workplace areas, preserving the protection characteristics, complying with manufacturer recommendations and external influences.
10.4.3.1 Equipment, devices and tools with electrical insulation shall be suitable for the involved voltages, and shall be inspected and tested in accordance with existing regulations or manufacturer recommendations.
10.4.4 Electrical installations shall be kept in safe operating condition, and their protection systems shall be periodically inspected and controlled in accordance with existing regulations and project definitions.
10.4.4.1 Electrical service areas, compartments and enclosures of electrical equipment and installations are exclusively intended for this purpose, and their use for storage of any objects is expressly prohibited.
10.4.5 For activities in electrical installations, adequate lighting and a safe working position shall be guaranteed for workers in accordance with NR 17 - Ergonomics, allowing free use of the upper limbs to perform tasks.
10.4.6 Laboratory and field electrical assays and tests, as well as commissioning of electrical installations, shall comply with the regulations set forth in items 10.6 and 10.7, and may only be performed by workers who meet the qualification, competency, training and authorization requirements established in this NR.
