Hardwood Floors April/May 2025

By Kyle Krueger

Wood flooring projects often require various electrically powered tools and equipment. Ensuring these devices are connected properly and compliant with electrical codes is crucial for safety, performance, and property protection. A key element in this process is adhering to the National Electrical Code (NEC®), particularly Article 590 (Temporary Installations). This article outlines the requirements for temporary wiring, emphasizing worker safety and equipment efficiency. Here’s why understanding and following these guidelines is essential. UNDERSTANDING ARTICLE 590: TEMPORARY ELECTRICAL INSTALLATIONS When using electrical equipment such as wood floor sanders, temporary wiring often is employed to power the tools. Article 590 of the NEC® offers relaxed wiring methods designed for quick installation and interchangeability while maintaining safety. Here’s a breakdown: Purpose – Article 590 allows simplified wiring methods for temporary installations, provided safety standards are upheld. These relaxed rules are influenced by OSHA’s Safety and Health Regulations for Construction, making safety a core focus. Other Code Requirements – While Article 590 modifies certain permanent wiring requirements, it does not replace them. If a specific situation is not addressed in Article 590, the general NEC® provisions for permanent wiring apply, even in temporary installations. Time Limitations – Temporary wiring can only be used during construction, remodeling, maintenance, or similar activities. Once the activity is complete, the wiring must be removed immediately. Authority Having Jurisdiction (AHJ) – Temporary wiring must be approved by the local inspection authority. Permits and inspections may be required based on regional regulations, ensuring installations meet unique conditions.

KEY REQUIREMENTS FOR WOOD FLOORING ELECTRICAL EQUIPMENT Temporary wiring for wood flooring tools must meet specific standards to ensure safe and reliable operation. Wiring Methods – Temporary wiring must use cables and cords suitable for the environment. Flexible cords like Type S, SO, and STO are used commonly in wood flooring projects because they are durable and adaptable to active workspaces. Additionally, cords must be protected from physical damage. Splices and Terminations – All splices must be made in suitable enclosures with covers. Flexible cords or cables entering enclosures with circuit breakers or devices must use appropriate termination fittings to ensure a secure connection. Overcurrent Protection – Overcurrent protection, such as circuit breakers, is essential to prevent excessive currents that could damage equipment or wiring. The cord or cable must be rated to handle the circuit breakers amperage rating to avoid overheating and potential fire hazards. Personnel Protection – Ground Fault Circuit Interrupters (GFCIs) are mandatory for single-phase temporary receptacles rated at 125 volts and 15-, 20-, or 30-amps. GFCIs disconnect power quickly in case of a ground fault, reducing the risk of electrical shock to the personnel using the electric equipment. For higher-voltage and amperage temporary equipment, either GFCI protection or an Assured Equipment Grounding Conductor Program compliant with OSHA standards is required.

the magazine of the national wood flooring association

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