Before the early 1990s, evaluating water-damaged electrical equipment was mostly left to municipal inspectors who had little expertise in making such evaluations. The Mississippi River Flood of 1993, one of the most significant natural disasters ever to hit the United States, cost the American public billions of dollars in damage, including severe damage to electrical equipment. As with earlier disasters, jurisdictional authorities and insurance companies were soon at odds over the degree of damage to electrical equipment that had occurred and whether the water-damaged electrical equipment could be repaired, replaced, or simply allowed to dry out.

The member companies of the Rosslyn, VA-based National Electrical Manufacturers Association (NEMA) have since developed and revised a booklet to assist in the decision-making process about how to fix damaged electrical equipment. Along with the information provided by NEMA in Evaluating Water-Damaged Electrical Equipment, the association advises that you take the following actions and ask these questions when evaluating water-damaged electrical equipment.

1. Follow National Electrical Code 110-11: Deteriorating Agents.
2. Determine the degree of damage. Was equipment underwater or did it get wet from rain or other causes? Electrical equipment may be exposed to water through flooding, firefighting activities, hurricanes, etc. As NEMA points out in Evaluating Water-Damaged Electrical Equipment, severe 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 be particularly damaging due to the corrosive and conductive nature of salt-water residue.
3. Determine the types of equipment being investigated, such as simple contact, sealed, electronic, etc. Electrical distribution, motor control, and power equipment, as well as transformers, conductor products, wiring devices, cable trays, motors, and electronic equipment, have unique characteristics. These should be considered when deciding whether water-damaged equipment should be repaired or replaced, along with other considerations, such as cost, ease of repair, ability to remove all contamination, and other factors.
4. Determine what liquids were involved, such as water, chemicals, oils, sewage, etc.
5. Find out how long the equipment was exposed to such damage.
6. Consult with the equipment manufacturer when repair or refurbishment is the plan of action. Follow the manufacturer's instructions and guidance in making repairs. When any questions arise, and before specific recommendations are formulated, it's often necessary to contact the original equipment manufacturer. Without doing so, attempts to recondition equipment can result in additional hazards due to improper cleaning techniques or the choice of cleaning agents.

In many cases, replacement of the equipment may become necessary (especially when abrasive cleaning methods are utilized and electrical-conducting surfaces or insulating materials are damaged, resulting in overheating and possible fire and shock hazards).

John D. Minick (john.minick@nema.org) and Joseph F. Andre (jfandre@verizon.net) are field representatives for the Rosslyn, VA-based National Electrical Manufacturers Association.