Nema's guidance on water-damaged electrical equipment
Electrical equipment exposed to water can be extremely hazardous if reenergized without proper reconditioning or replacement. Reductions in integrity of electrical equipment due to moisture can affect the ability of the equipment to perform its intended function. Damage to electrical equipment can result from flood waters contaminated with chemicals, sewage, oil, and other debris, which will affect the integrity and performance of the equipment. Ocean water and salt spray can also be particularly damaging due to the corrosive and conductive nature of the salt water residue. Distributors of electrical equipment should not supply any inventory that has been subjected to water damage.
A working knowledge of electrical systems and the equipment in question is needed to evaluate damage due to contact with water. The original manufacturer of the equipment should be contacted if questions arise or recommendations are needed. In many cases following water damage, replacement may be necessary. After consultation with the manufacturer, some larger types of electrical equipment may be reconditioned by properly trained personnel.
A National Electrical Manufacturers Association publication, Evaluating Water-Damaged Electrical Equipment, provides specific guidance on whether products that have been exposed to water should be replaced or reconditioned. The publication provides information to building owners, maintenance workers, electrical inspectors, electricians, and users of electrical products on how to evaluate electrical equipment that has been exposed to water through flooding, fire-fighting activities, and hurricanes. It includes a table showing the requirements and recommendations associated with various categories of electrical equipment that have been subject to water damage.