Flood water, whether due to natural causes or infrastructure failure can have catastrophic effects when it comes to electrically powered equipment and appliances. It is always best to contact your supplier for proper procedures, but these tips can help you evaluate damaged electronics.
Often in a rush to get everything up and running after a power outage, many people forget that electrical equipment exposed to water can be extremely hazardous or even deadly. Submerged outlets or electrical cords can energize standing water. First and foremost, never enter a flooded area until it has been determined safe by a professional.
Great care needs to be taken when attempting to restore electrical systems and power to water-damaged equipment. Electrical equipment should never be reenergized without performing a proper evaluation.
The National Electrical Manufacturers Association (NEMA) offers pages of guidelines for evaluating water-damaged electrical equipment. Here is a small sampling of NEMA recommendations.
Reductions in the integrity of electrical equipment due to moisture can affect the ability of the equipment to perform its intended function. Damage to electrical equipment can also result from floodwaters 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 the saltwater residue.
Electrical Distribution Equipment
Electrical distribution equipment usually involves switches and low-voltage protective components that are critical to the safe operation of distribution circuits. Exposure to water can affect their ability to protect these circuits.
Motor Control Equipment and Motor Control Centers
Motor control centers contain many different components, including fuses, circuit breakers, controllers, overload relays, and adjustable speed drives, as well as components such as buswork, insulators, and enclosures. Water may affect fuses and can degrade the insulation. Corrosion, loss of lubrication, and insulation quality can also be expected in contactors and starters. Solid-state motor controllers, adjustable speed drives, and those electromechanical contactors or starters with integral electronic circuitry will be more severely affected by water.
Power equipment involves low-voltage or medium-voltage protective devices within an overall switchgear assembly. The assembly may also contain cabling, buswork with appropriate insulators, current transformers, electromechanical or electronic relays, and metering. Reliable operation of the protective devices is vital to system safety. These devices can be adversely affected by water as far as operation of mechanisms and degradation of insulation materials. Furthermore, low-voltage power circuit breakers usually incorporate electronic trip units; the functioning of these units will be impaired. Similarly, the functionality of electronic protective relays and meters can be impaired.
Conduit and Tubing
In the case of 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.
Wire and Cable
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 could become a shock hazard when energized after being exposed to water.
Motors that have been flooded by water may be subjected to damage to insulation, capacitors, and internal components.
Electronic Products, Including Signaling, Protection, Communication Systems, and Industrial Controls
Equipment used in signaling, protection, and communication systems generally contain electronic components, and the exposure of such equipment to water or corrosives can adversely affect the reliability of those systems.
A battery exposed to moisture is subject to corrosion and rust. The rate of corrosion damage can be impacted by the type and amount of moisture. For example, salt water may increase the corrosion rate when compared to freshwater.