Due to recent flooding in the North East, Southwire has received multiple calls regarding water damaged cable. It is important to note that all electrical equipment can be very dangerous after flooding if the proper measures are not taken to ensure product and wiring safety. Some electrical items and cable may be reconditioned by professionals, while other items will need to be completely replaced.

Wire and cable manufacturers at NEMA and Underwriters Laboratories (UL), state that Type NM-B cable (which includes Southwire’s Romex® Brand)  needs to be removed if the cable has been submerged in flood waters. If the ends of the cable are immersed for any period of time, the internal paper wrapping around the bare equipment-grounding conductor will absorb and transfer the water into the cable assembly. The water may then start degrading the insulation or corroding the conductors. If the cable comes into contact with contaminated water, the contaminants may interfere with the insulation or conductors. Over time, failures can occur. In a flooding situation, there is no way of knowing how long the cables were immersed in water, or what types of potentially corrosive substances may have been in the flood waters. As was widely reported after Hurricane Katrina, raw sewage and chemicals were known to be in the floodwaters afflicting the Gulf Coast region of the United States.

Nonmetallic-sheathed cable has not been investigated by UL for this type of exposure. Therefore, it is not possible for UL to state that cable in a particular installation is acceptable for continued use after having been subjected to the flooding. The safest approach is to replace any nonmetallic-sheathed cable that was immersed in water for any period of time during the flooding.

 

For additional references and guidelines for handling water damaged electrical equipment and wiring:

From NEMA

From UL