Take Precaution Re-energizing your Home’s Electrical System After There Has Been a Flood
There is a common misconception that electrical systems submerged in flood water can be dried out, treated and reused, like wood studs in walls. However, it does not work the same for your property’s electrical system. This applies to homes, businesses and industrial buildings. Once electrical equipment is submerged, it is damaged and un-repairable. It must be completely replaced with new equipment, components and wiring.
Flood water contains a very nasty cocktail of chemicals besides just H2O. When a flood occurs, vehicles with gas, diesel, oil and other manmade chemicals are released. Underground fuel tanks, heating oil tanks, sewage and chemicals released in containers from grocery stores, warehouses and other facilities mix into the flood water. Wiring and electrical equipment is not designed or built for this onslaught of a chemical cocktail.
There is only a small handful of equipment and components that can be submerged in water and even then, it is tested with salt or fresh water. These types of electrical systems are designed for fountains, swimming pools, spas, hot tubs and specific identified wells or other applications. The typical building wiring system is designed for dry or damp locations only. These systems cannot get wet. Once they do, the certification by the testing laboratory is null and void.
The problem is that the flood water containing the chemicals that was described above breaks down the materials, such as the thermo-plastic that makes up wire (conductor) insulation. As the chemicals quickly degrade the insulation, short circuits and ground faults will occur causing fire or shock hazards. Further, the National Electric Code and OSHA specifically require that the electrical system be intact and free from short circuits and ground faults.
The National Electric Code in Section 110.3(A) and (B) require that the electrical system and the components be inspected and identified for the use and purpose, and installed in accordance with the listing and instructions included within the listing of the electrical products. This includes wire and cable, switchgear and panelboards, circuit breakers and fuses, switches, timers, luminaires and receptacle outlets and associated devices. None of this equipment is designed nor tested under the equipment safety standards for submersion in flood water.
There is no listed or safe fix to electrical equipment that has sustained flood damage. The only remedy when rebuilding and repairing the structure is to remove and replace electrical distribution systems. The Nationally Recognized Testing Laboratories have taken many positions on electrical equipment repair after a flood. NEMA (National Electrical Manufacturers Association) recommends that you contact the manufacturer to see if any of the equipment can be reconditioned after a flood (NEMA Guideline courtesy IAEI) . Be aware this is on a case by case basis depending on the type of equipment. Additional certification by the NRTL or field evaluation may be required before energizing. Equipment that is possibly capable of being reconditioned is industrial or large distribution bussing. To rest-assure in avoiding a future catastrophe, residential and commercial electrical equipment that was submerged in flood water should be replaced.
And lastly, under NO circumstance re-energize and electrical system that has been flooded until you have had a licensed electrical contractor with a permit from the jurisdiction and the electrical inspector concur that the system is safe to re-energize. No additional death is needed after the catastrophic events of a flood over something as critical as your property’s electrical system and its safe operation.
For more information regarding electrical system re-energizing, contact your local city, county or state building department and electrical inspector. Additionally, contact the manufacturer for a specific question on electrical equipment that has been flooded.
David Hill is a certified electrical inspector and licensed supervising electrician, an electrical equipment evaluator for Intertek Testing/ETL a Nationally Recognized Testing Laboratory and the President of the International Association of Electrical Inspectors with 47 years of experience in the industry. Founder of ElectricalEducation.com and co-founder of QiCommunity.com.