In the Wake of Katrina: Managing Water-Damaged Electrical Equipment

10/01/2005


News coverage this summer has been fraught with images of destruction—and unfortunately, death—due largely to Hurricane Katrina, but also Hurricanes Dennis, Emily, and most recently, Rita. Sadly, the number of hurricanes the country faces this year might not be limited to this destructive foursome, as hurricane season doesn't conclude until November. In fact, prior to Rita, the National Oceanic and Atmospheric Administration predicted another 11 to 14 tropical storms, five of which might evolve into major hurricanes.

The floods wrought by these hurricanes have resulted in incalculable damage. And one thing that tops the list is water damage to electrical distribution and control equipment.

No matter where your customer is, if they are a victim of major flooding, as a consultant, you will face many frantic questions. When it comes to electrical systems, questions at the top of the list concern whether equipment can be dried out; whether circuit breakers are OK to use; and whether switchboards can be re-energized.

The simplest rule of thumb is this: Electrical equipment that has been submerged must be serviced or replaced. But what, exactly, can be saved and what must be scrapped?

First, even attempting to dry out electrical equipment, in many cases, will still leave portions of the current-carrying components with wet or damp surfaces. Some parts are difficult to dry because they may be in contact with insulators or other materials that prevent them from being completely dried out and cleaned of debris. Residual debris or wet surfaces can also result in a loss of dielectric spacing within the equipment, which could produce a hazard upon re-energization. Other hazardous conditions can also develop after re-energization if untrained personnel try to disassemble and reassemble equipment.

For certain types of equipment, such as switchboards, switchgear and medium-voltage circuit breakers, reconditioning may be possible, but the ability to do so will vary and may include repair or replacement of internal components or of the complete circuit breaker (see table on p. 60 for lists of equipment that must be replaced and types that might be reconditioned). Again, disassembly should be performed only by trained factory service personnel who are familiar with equipment design and function.

If your customers have equipment located in flooded areas, but it was not submerged, it should be inspected by a qualified person to determine whether moisture has entered the enclosure. If there are any signs of moisture or damage, the equipment should be replaced or repaired.

Other considerations

What if your customer has equipment with field-replaceable interior components? Generally, this situation is limited to a load center or panelboard product where the entire interior assembly can be removed and replaced as a unit. It is possible that enclosures can be reused in this situation if they have not been subjected to physical damage and if they have been properly cleaned of all debris and foreign materials. Consideration must also be given to other components in the electrical system, such as conductors—wire, cable and bus—junction boxes and termination points.

Be sure to make customers aware that certain kinds of cleaning agents for removing debris or residue, especially petroleum-based cleaners, can be hazardous when applied to the current-carrying portions of electrical equipment. Additionally, some cleaning and lubricating compounds can cause deterioration of non-metallic insulating or structural portions of equipment. Abrasives or sandpaper should not be used to clean current-carrying parts of equipment.

Be proactive

The only thing one can predict about natural disasters and flooding caused by weather events is that they are going to occur. Any information one can provide to customers after a calamity—or better yet, before—is going to increase their chances of survival.

Resources are typically in place from manufacturers to help customers evaluate water-damaged equipment and make recommendations. For example, in the wake of Katrina, home and business owners with concerns about the operation and safety of damaged electrical systems and equipment were able to call Square D's toll-free customer information center around-the-clock.

Additionally, Square D also activated its "WE CARE" program in FEMA-declared disaster areas in several states to address public safety issues and support electrical personnel as they repaired damaged electrical structures and systems.

In summary, there may be no more appropriate time than the present to review rules regarding water-damaged equipment. Adhering to these rules will make your customers feel safer; reminding them of the rules will make you a good neighbor.

Must Be Replaced in Entirety

Molded-case circuit breakers

Solid-state motor starters

Multi-metering equipment

Adjustable speed drives

Load centers or panelboards

Fuses

Dry-type transformers

Lighting

Low-voltage bus

Starters, push buttons and limit switches

All solid-state components

Programmable logic controllers


May Be Reconditioned*

* The ability to recondition will vary and may include repair/replacement of internal components.

Switchboards

Motor control centers

Switchgear

Panelboards

Iron frame low-voltage circuit breakers

Liquid-filled power transformers

Cast-resin transformers

Medium-voltage circuit breakers

Medium-voltage bus

Low-voltage bolted pressure switches

Some electro-mechanical relays and contactors

Medium-voltage switches





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