Always Replace Water-damaged Electrical Components

Water and electricity don’t mix.

You know that, but many of your customers, though aware it is dangerous to plug in equipment when on wet surfaces or in standing water, do not understand how damaging water exposure can be for the wiring and electrical components of their properties.

In fact, in homes and buildings that have been flooded, most electrical system components that were under water are no longer safe, even after they have been dried and cleaned. They must be replaced.

“In the normal electrical distribution system, the performance ability of electrical equipment and components is primarily dependent on clean, corrosion-free conductive contact surfaces and by the equipment’s dielectric insulation capabilities,” explains John Minick, field representative for the National Electrical Manufacturers Association (NEMA). “Water-damaged equipment, whether through floodwaters or other means, negates that ability and raises the risk of future equipment failure and possibly fire and shock hazards to unknown levels. Expedience and the cost of rebuilding are certainly key factors in helping people regain a sense of normalcy after disasters such as hurricanes and floods, but the possible cost concerning property loss through fire and deaths through shock hazards that may be created as a result of the misuse of water-damaged electrical equipment has to be of equal importance.”

An electrical contractor in Metairie, La., has dramatic first-hand experience of the damage water can cause. His company’s electricians’ rewire structures in the New Orleans area were damaged by Hurricane Katrina and the flooding that followed.

“We see damaged outlets, circuit breaker panels, air conditioning units ruined by water,” the contractor says. “All metal items are corroded, including copper and aluminum cables. White jackets of Romex cable have turned black from the brackish waters, and long after water subsided, you can squeeze water from the cable.

“It is absolutely critical that these components be replaced,” he emphasizes. “Connecting power to an electrical system containing them poses a serious fire hazard and other risks.”

As work continues to rehabilitate damaged structures, crews continue to find that many components of electrical panel boards, controllers, switchboards, transformers, appliances, etc., are not visible without completely dismantling the equipment in question, the contractor says.

“Contaminated water that oxidizes metal contact points will increase resistance,” he continues. “This resistance will generate heat directly in proportion to the amount of current that flows through the oxidized metal. The more heat that is generated, the more resistance is increased. This ‘snowballing’ effect can lay dormant until an appliance is used or until loads are increased across a contact point, thereby becoming a fire hazard some time after the electricity is turned on.”

Flood-damaged buildings in New Orleans are extreme examples of how water destroys electrical systems, but damage can occur when water from flash floods, broken water pipes or any other source covers electrical components. Often there can be no visible sign of damage.

NEMA and other industry organizations agree that flood-damaged components should 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.

Several sections of National Electrical Contractors Association (NECA) installation standards say that electrical equipment and inside wiring not intended to get wet that has been submerged in water, and especially dirty water, should be replaced.

However, many property owners, especially those of private residences, do not understand the seriousness of connecting a damaged system to power, and may assume that once dried and clean, the structure’s system is safe.

If called to work in water-damaged properties, you can provide a valuable service to customers by making them aware of the risks of restoring power to components that have been under water.

One guide to utilize is NEMA’s Guidelines for Handling Water Damaged Electrical Equipment. It provides advice about the safe handling of electrical equipment that has been exposed to water. It outlines which items will require complete replacement and which a trained professional can recondition. Equipment covered includes electrical distribution equipment, motor circuits, power equipment, transformers, wire, cable and flexible cords, wiring devices, GFCIs and surge protectors, lighting fixtures and ballasts, motors, and electronic products including signaling, protection, communication systems, industrial controls and cable trays.

According to NEMA, the brochure is incorporated into the Federal Emergency Management Agency (FEMA) manual, Principles and Practices for the Design and Construction of Flood Resistant Building Utility Systems.