Flooded Electrical Systems and Appliances

Kenneth Hellevang, Extension Engineer

Before entering a flooded building (house, garage, barn or shop supplied with electricity), be sure that the electricity has been shut off completely to any portion of the electrical system that may have been submerged in floodwater. This typically is done with an external disconnection for the building. Frequently, the power supplier will disconnect the electricity.

Electrical wiring and electrical system equipment that has been exposed to floodwaters can be extremely dangerous to energize without being examined and repaired or replaced. Floodwaters can cause corrosion, and sediment or other contaminants can lodge in the equipment. Damage to wiring or fixtures may not be apparent initially. Appliances that have been exposed to floodwaters should not be operated until they have been reconditioned. Running equipment before it is properly reconditioned could damage it seriously and may cause a fire or electrical shock to people.

If you need electrical power, a licensed electrician can install a temporary electrical panel or you can use a generator. The electrical system should be checked and certified by an electrician or electrical inspector to assure that any part of the system is safe to energize.

When using electrical appliances such as power washers, vacuums and other cleaning equipment, make sure you are using an extension cord with a ground fault circuit interrupter (GFCI) or install a GFCI in the electrical circuit.

Electrical Circuits and Equipment

If the home fuse or circuit breaker panel has been exposed to floodwaters, it should be disconnected immediately because this poses a serious risk of electrical shock or fire. Request your power supplier disconnect your power immediately before starting any cleanup work.

All breaker panel boards, breakers, fuses, disconnect switches, controllers, receptacle outlets, switches, light fixtures and electrical heaters that have been exposed to floodwaters must be replaced. Electrical wiring needs to be replaced unless it is listed for use in wet locations. Splices and terminations must be checked to make sure they comply with the National Electrical Code. All wiring must comply with State and National Electrical Code (NEC) to ensure human safety and reduce fire hazards.

Hire an electrician to do the work due to the safety hazards associated with improper electrical wiring. A homeowner can perform his or her own electrical work if competent with electrical wiring and he or she knows current code. The person doing his or her own work is required to contact the local electrical inspector and get approval of the electrical work that is going to be done before any electrical work is done. Once the work is done and the installation is ready for inspection, the inspector will check the wiring to ensure that the work meets code. For example, the NEC requires arc fault circuit interrupters and tamper-resistant receptacles in dwellings.

If you have any questions about your electrical system, contact a North Dakota licensed electrical contractor, the North Dakota State Electrical Board or your local electrical inspector. The North Dakota State Electrical Board’s Web site at www.ndseb.com has information on the electrical codes as well as names of licensed contractors in your area.

Electrical Appliances and Electronics

Household appliances with motors or electrical components such as dishwashers, clothes washers, ovens and ranges that have been exposed to floodwaters should be reconditioned by an approved manufacturer’s representative or replaced. Electric motors and appliance electronics must be reconditioned or replaced because moisture and floodwater contaminants can cause damage to the unit and create electrical hazards when energized. Get a cost estimate to recondition the appliance; replacement may be more cost effective.

Refrigerators and freezers with foam insulation and sealed components may have little water damage if the motor or electronics were not in water, but since they hold food, they should be cleaned and disinfected. If the motor or electronics were submerged, the appliance should be reconditioned prior to use. Get a cost estimate to recondition the appliance; replacement may be more cost effective. To clean appliance surfaces, use a heavy-duty cleaner and hot water, then a bleach solution.

Get a cost estimate from a professional for repairing televisions, radios, computers and similar equipment to decide if the device is worth repairing. Replacing the electronic equipment may be more cost effective.

Related publications

”Evaluating Water-Damaged Electrical Equipment" published by the National Electrical Manufacturers Association (NEMA). To obtain a copy, go to the NEMA Web site at www.nema.org/stds/water-damaged.cfm#download. You will need to provide your contact information before downloading the document.