NEMA offers guidance on water-damaged electrical equipment

Many regions have been hit with flooding, and even professionals may need to seek guidance about if electrical equipment exposed to water should be reconditioned or replaced. Experts offer free advice.

By Control Engineering Staff June 27, 2008

Rosslyn, VA – Many regions have been hit with flooding, and even professionals may need to seek guidance on whether or not electrical equipment exposed to water should be reconditioned or replaced. A National Electrical Manufacturers Association (NEMA) publication, Evaluating Water-Damaged Electrical Equipment , provides guidance about replacement or reconditioning of

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The NEMA publication instructs maintenance workers, electrical inspectors, electricians, building owners, and users of electrical products on how to evaluate electrical equipment that has been exposed to water through flooding, fire-fighting activities, and hurricanes. A table shows requirements and recommendations associated with categories of electrical equipment that have been water-damaged, useful for system integrators, original equipment manufacturers, end-users, and distributors of such equipment. Such equipment can be hazardous if reenergized without proper reconditioning or replacement. Reductions in integrity of equipment due to moisture can affect performance. Damage can result from flood waters contaminated with chemicals, sewage, oil, and other debris. Ocean water and salt spray can be particularly damaging due to the corrosive and conductive nature of salt water residue. Distributors should not supply inventory that has been water-damaged. A working knowledge of electrical systems and equipment is needed to evaluate such damage due to contact with water.

The original manufacturer should be contacted with questions or if recommendations are needed. Following damage, replacement may be necessary. After consulting the manufacturer, some larger types of electrical equipment may be reconditioned by properly trained personnel.What itemsc products including signaling, protection, communication systems, industrial controls, and cable trays. For instance, Transformers – Exposure of transformers to water can cause corrosion and insulation damage to the transformer core and winding. Ability of the transformer to perform its intended function in a safe manner can also be impaired by debris and chemicals, which may be deposited inside the transformer during a flood. Water and contaminates will also damage the transformer fluids. Cable tray – Carefully inspect the cable tray system to determine if its mechanical and / or electrical integrity has been compromised. Repair or replace any damaged portions per original installation requirements. Remove all debris from the cable tray. If any labels warning against the use of the cable trayas a walkway have been damaged, obtain new labels from the manufacturer and apply as required. Power equipment – Replace fusible units of fused equipment. The remainder of the apparatus may be suitable for refurbishing in close consultation with the manufacturer. In all cases, great attention must be paid to the thorough cleaning, drying, and testing of insulators and insulation material. NEMA provides copies of the document to electrical inspectors, building officials, and field representatives are making copies available during visits to the Midwest and other communities across the U.S. NEMA is inviting organizations such as International Code Council and National Joint Apprenticeship and Training Program of the International Brotherhood of Electrical Workers to make the free document available to constituents. A complimentary copy of NEMA’s Evaluating Water-Damaged Electrical Equipment – Control Engineering News Desk Register here and scroll down to select your choice of eNewsletters free .