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Storm FAQs

Q. What are the key steps for proper evaluation of water-damaged electrical equipment?

  1. Identify the water source. The water source, the duration of exposure, and the presence of contaminants has a significant impact when determining what equipment must be replaced and what equipment may be reconditioned.
  2. Conduct the evaluation. This may include visual observations of damage, operational tests, or performance testing to determine the extent of equipment damage. Equipment evaluations should be performed by qualified persons only.
  3. Contact the manufacturer. The original manufacturer of the equipment should be contacted if any questions arise or specific recommendations are needed. Have the information or findings in Step #1 and Step #2. Document the nameplate data, product labels, or any other identifying marks on the equipment. Photos &/or video are a plus. An onsite visit may be necessary. Attempts to recondition equipment without consulting the manufacturer can result in additional hazards.
  4. Refer to the NEMA Evaluating Water-Damaged Electrical Equipment Guidelines for additional information and manufacturer recommendations.
  5. Consult with your local Authority Having Jurisdiction to establish permitting and inspection requirements.
  6. Replace or recondition the electrical equipment. All work should be performed by qualified persons only.

Q. When replacing receptacles that have been submerged in flood waters, do the requirements outlined in Section 406.4(D) of the National Electrical Code apply?

Yes. Replacement of receptacles shall comply with 406.4(D) (1) through (D) (6), as applicable. Consult with your local Authority Having Jurisdiction to establish permitting and inspection requirements.

Q.  Do I need to replace the wiring that has been exposed to water due to flooding?

When any wire or cable product is exposed to water, any metallic component (such as the conductor, metallic shield, or armor) is subject to corrosion that can damage the component itself and/or cause termination failures. If water remains in medium-voltage cable, it could accelerate insulation deterioration, causing premature failure. Wire and cable listed for only dry locations may become a shock hazard when energized after being exposed to water. Any recommendations for reconditioning wire and cable in the NEMA Evaluating Water-Damaged Electrical Equipment Guidelines are based on the assumption that the water contains no high concentrations of chemicals, oils, etc. If it is suspected that the water has unusual contaminants, such as may be found in some floodwater, the manufacturer should be consulted before any decision is made to continue using any wire or cable products.

Q. My panelboard and molded case circuit breakers have been exposed to water due to flooding. Can I simply clean the equipment and reuse it?

The protective components of an electrical distribution system are critical to the safe operation of circuits. Their ability to protect these circuits is adversely affected by exposure to water and to the minerals, contaminants, and particles, which may be present in the water. In molded-case circuit breakers and switches, such exposure can affect the overall operation of the mechanism through corrosion, through the presence of foreign particles, and through loss of lubrication. The condition of the contacts can be affected, and the dielectric insulation capabilities of internal materials can be reduced. Further, some molded-case circuit breakers are equipped with electronic trip units, and the functioning of these trip units can be impaired. Water may affect the filler material of fuses and will degrade the insulation and interruption capabilities. Distribution assemblies contain protective components together with the necessary support structures, buswork, wiring, electromechanical, or electronic relays, and meters. Exposure to water can cause corrosion and insulation damage to all of these areas. In the case of exposure of distribution assemblies to water, contact the manufacturer before further action is taken. Air drying and washing of water-damaged products of this type should not be attempted.

Q. Does conduit or tubing need to be replaced when exposed to water?

In the case of flooding, fire-fighting activities, or other instances of unusual water exposure, conduit and tubing must be carefully inspected to determine if the mechanical and electrical integrity of the conduit/tubing system has been compromised. Flood waters, in particular, may be contaminated with oil, chemicals, sewage, and other debris that could enter the conduit/tubing and prevent a clear path for the replacement of conductors or cables. As part of the inspection process, ensure that the interior of the conduit/tubing is clear. Also, contaminants may affect the physical properties of metallic and nonmetallic materials and the corrosion protection for electrical equipment, as required in NEC Section 300.6. Since every situation has unique circumstances, the services of an experienced evaluator should be used. The manufacturer can also be consulted for additional assistance.

Q. What type of cleaning agents can be used on water-damaged electrical equipment?

Attempts to recondition equipment without consulting the manufacturer can result in additional hazards due to the use of improper cleaning agents, which can further damage the equipment. Refer to Section 110.11 of the National Electrical Code for additional information on the hazards of cleaning and lubrication compounds.

Q. Does the National Electrical Code have any other requirements specific to reconditioned electrical equipment.

Yes. Section 110.21(A) (2) contains specific requirements for reconditioned electrical equipment.

Q. Does NEMA offer any other guidance related to natural disasters and storm recovery?

Yes. Visit the NEMA Storm Reconstruction Toolkit. The 300-plus member companies of the National Electrical Manufacturers Association (NEMA) and its staff of experienced engineers, electricians and electroindustry experts spanning more than 50 industry product sections stand ready to assist consumers, businesses, utilities and government when preparing for and reconstructing after a disaster.


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