Q: Can I wash and dry equipment and place it back into service?
A: Attempts to recondition equipment can result in additional hazards because of improper cleaning techniques and unsuitable cleaning agents. Reconditioning of equipment should not be performed without consulting the manufacturer and performing a thorough evaluation by qualified persons with a working knowledge of the electrical system and equipment. This evaluation should include the degree of flooding, the age of the equipment, the length of time the equipment was exposed to water and what, if any, contaminants were in the water.
Examples of equipment that cannot be reconditioned and should be removed from service are:
Molded-case circuit breakers, fuses, dry type transformers, devices such as receptacles and switches, GFCIs, AFCIs, transient voltage surge protective devices, and wiring not suitable for wet locations.
Examples of equipment that may be reconditioned by properly trained personnel after consultation with the manufacturer are as follows: Busways, panelboards, enclosed switches, transfer switches, fire-pump controllers, motor controllers, motor-control centers, switchboards, switchgear, liquid-filled transformers, cast-resin transformers, and motors.
Q: Do I need to replace the wiring that has been exposed to water due to flooding?
A: Wiring that is listed for dry locations only, such as non-metallic sheathed cable, may become a shock hazard when reenergized (due insulation failure) and therefore should be replaced. Wiring that is listed for wet location may be reused provided the ends of the wire or cable have not been exposed to water. When the ends of a conductor have been exposed to water, the cable may be purged to remove the water. All wiring that has been exposed to water needs to be evaluated by qualified persons with a working knowledge of the electrical system and equipment. This evaluation should include the degree of flooding, the age of the cable, the length of time the cable was exposed to water, and the source of water and identification of any contaminants that were in the water. The manufacturer should be consulted prior to reenergizing any wire or cable
Q: My panelboard and molded case circuit breakers have been exposed to water due to flooding. Can I wash the equipment and reuse it?
A: Molded case circuit breakers that have been exposed to water should be replaced. The internal electrical components, such as electrical contacts, could be adversely affected by exposure to water which can lead to arcing, overheating, and eventually a total breakdown of the circuit breaker that could cause personal injury, property damage, or unintended power interruptions. The panelboard needs to be evaluated by qualified persons with a working knowledge of the electrical system and equipment. This evaluation should include the degree of flooding, the age of the panelboard, the length of time the panelboard was exposed to water, the source of water, and identification of any contaminants that were in the water. The manufacturer should be consulted for the proper reconditioning procedure before the panelboard is reused.
Q: Can I air dry a molded case circuit breaker and then reuse it after it has been exposed to flood conditions?
A: In accordance with the NEMA Evaluating Water Damaged Electrical Equipment guide, no. The protective components are critical to the safe operation of distribution 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.
Q: If NM-B Cable is completely submerged do I have to replace it?
A: Yes, non-metallic sheathed cable is a dry location wiring method and when exposed to water, the conductors are subject to corrosion that can damage the component itself and/or cause termination failures. Wire and cable listed for only dry locations may become a shock hazard when energized after being exposed to water.
Q: If the electrical service on the home is submersed do I have to replace?
A: Yes. The panel is subjected to many different types of corrosive materials that could affect the ability of the overcurrent device to function in the future.
Q: Do I have to replace the NM-B cable if it is subjected to flood waters or can I just allow it to dry out and not replace?
A: If the NM-B cable is submersed it must be replaced.
Q: When inspecting a commercial office building that was affected by a flood, how should I instruct the electrical contractor to replace the EMT conduit or is it allowable to clean and re-use?
A: You must first confirm the conduit’s integrity is still intact and is free from any foreign objects from the flooding before you decide to either replace it or re-use.