Major storms this hurricane season wreaked havoc on the southeastern United States, including Puerto Rico and the U.S. Virgin Islands. These storms created weather hazards as well as dangerous conditions for power utilities and restoration efforts. Mass water damage occurred to residential and commercial electrical components and equipment. This creates significant safety hazards to the general public and those inspecting, replacing and refurbishing them.
Following a major storm, restoring power is the highest priority. However, floodwaters can affect circuit breakers, fuses, transformers, wiring, light fixtures, arc- and ground-fault circuit interrupters, and appliances. Furthermore, saltwater is corrosive, and floodwaters often contain debris, sewage and chemicals.
Beyond the damage water can cause to electrical systems, structures in which electrical components and wiring have experienced water damage may not be properly inspected. Depending on state or local laws, certified electricians may be permitted to inspect this water damage. In other cases, only government inspectors are permitted to do such work. When an unqualified person conducts an inspection, unsafe wiring, components or equipment may go undetected, which may lead to more damage and loss of life.
Following Hurricane Katrina in 2005, ELECTRICAL CONTRACTOR contributing editor Jeff Griffin wrote about the problem of properly inspecting water-damaged electrical equipment and the dangers and hazards that can result if such potential damage is ignored. (See “The Disaster After the Disaster?”)
Following Hurricane Sandy in 2012, utilities in the Northeast pulled all electrical meters and did not restore power to customers without proper certification that electrical components and equipment were safe. In the intervening years, perhaps awareness has grown in the electrical industry.
When water-damaged wiring, components and equipment dry out, there is still a risk of fire and electrical malfunction once power is restored. However, the effects may not occur immediately, and there is no way to definitively know the long-term impact of water damage. As a result, it is recommended that wiring, electrical components and equipment subject to water damage be replaced.
The National Electrical Code (NEC) states that equipment cannot be exposed to agents—including fumes, vapors and liquids—that can have a deteriorating effect on the equipment. In addition, a number of National Electrical Installation Standards indicate electrical equipment and inside wiring subject to submerged water should be replaced.
The National Electrical Manufacturers Association states that proper electrical inspections should be conducted by technically competent, recognized authorities having jurisdiction. In 2016, it issued a guide, “Evaluating Water-Damaged Electrical Equipment.” According to NEMA, it was “designed with participation from our many manufacturers to help building officials and inspectors better understand how to evaluate” water-damaged electrical equipment.
Depending on the age and condition, some damaged equipment can be safely refurbished by proper personnel. However, it should always be done in consultation with the manufacturer. According to NEMA, equipment that can be refurbished includes panelboards and switchboards, high- and low-voltage circuit breakers, conduit and tubing, wire suitable for wet environments and motors. (See "Knowing the Full Story" for more on refurbished equipment.)
“Evaluating Water-Damaged Electrical Equipment” also indicates fittings, lighting fixtures, wiring for dry use, arc- and ground-fault circuit interrupters, switches, dimmers, relays, and fuses should be replaced after experiencing water damage or flooding. The document lists more items that must be replaced.
When waiting for equipment and components to be returned to service and power to be restored, use care with portable generators; they pose electrical and fire hazards and emit carbon monoxide. Use outdoors only. If anyone gets dizzy, has headaches, or is nauseated, get them to fresh air and seek medical attention.
To avoid fires, turn off the generator and allow it to cool before refueling. Store flammables in approved containers and away from ignition sources. Protect against shock by following the manufacturer’s instructions for grounding the generator, use GFCIs, and keep the generator dry.
Never connect a portable generator directly to the electrical system, unless you use a properly rated transfer switch that has been installed by a qualified electrician. Remember, attaching directly to an electrical system can energize the wiring systems for great distances and injure others working on the line.