April Showers Can Lead to Floods: Water-damaged electrical equipment

Published On
Apr 15, 2021

Springtime brings more moderate weather after a long, cold winter. It also brings damaging storms. Thunderstorms are more frequent in the spring than during other times of the year, as are tornadoes. Hurricane season begins in June and runs through November.

In some areas of the United States, spring is the annual rainy season with frequent and prolonged rain showers that cause flooding. The usual determining factor for flood exposure is whether a building is within the 100-year flood plain. Flood zones are determined by the Federal Emergency Management Agency. Flood maps are only reliable until the next construction project changes the grading in an area, resulting in changes to the drainage characteristics. Floods can then occur that don’t match the flood model. If a building is in the official flood plain, mortgage holders will usually require the owner to have flood insurance. The grading changes could still expose other owners to an unforeseen 100-year flood, however.

Floods can also exceed the 100-year level. A few years back, South Carolina experienced what has been referred to as a thousand-year flood. It crossed the previous flood boundaries. This level of flooding is extremely rare.

Several hurricanes have caused widespread damage, including hurricanes Andrew, Katrina and Harvey. Hurricane Andrew was notable for the widespread structural damage caused by high winds. The roof damage exposed electrical equipment in buildings to water damage. Hurricane Katrina caused flooding along the Gulf Coast in cities near and below sea level, most notably in New Orleans.

Cold weather alone causes major damage. So far this year, large areas of the United States have experienced temperatures that are much colder than normal, including in Texas, where power failures during extremely cold weather caused overhead piping to freeze and break, showering equipment in water. Colorado, Wyoming and Nebraska experienced severe weather in March.

After the incident

Once a flooding incident has occurred, the equipment should be immediately deenergized, if it isn’t already. Do this from a safe location to prevent injuries. Deenergization can prevent further damage to equipment.

The water from any of these sources isn’t particularly clean, and that includes water in sprinkler piping, which tends to be in the pipes for many years, corroding them over time. When the sprinklers discharge, the water is often initially rusty. As a sprinkler head continues to operate, the water will usually clear up. Accidental sprinkler discharge is rare, but it does happen. Sprinkler protection is a very important element of property protection. They should not be omitted on the basis that they could expose equipment. They are there to prevent a much worse problem. If discharge does occur, disconnecting the affected equipment upstream and away from the area is recommended. The damage from broken sprinkler heads or broken piping is usually confined to a small area if detected soon enough.

Flood water is a different hazard to equipment than sprinkler water. It often affects a lot of equipment in a building and it may contain sediment, such as plant residue, sticks and mud, or hazardous materials, such as oil. An impending flood hazard usually has some advanced warning, which may allow some time to deenergize equipment and therefore mitigate some electrical hazards, including arcing and shock hazards.

Flooding from Hurricane Katrina severely damaged electrical equipment in several cities along the Gulf Coast, which led to a lot of public discourse. There were some university professors who indicated that equipment could simply be washed off and placed back in service. Many in the electrical industry, including electrical inspectors, indicated that it wasn’t safe. For more about emergency inspections in New Orleans after Katrina, read “Disaster After the Disaster” from the May 2006 issue of Electrical Contractor.

A great resource after a water damage incident is NEMA GD-1, “Evaluating Water-Damaged Electrical Equipment.” This will help in the initial evaluation of the equipment and help determine what equipment can be restored. The first questions are whether the equipment is damaged and how much exposure it has had. If the room is flooded, that is clearly a significant exposure problem. If the equipment has had some fine water spray from a single sprinkler head, it may not be too significant. Immediate action to clean off the equipment may minimize the damage.

If electrical equipment requires cleaning, it is important to know that there are a variety of cleaning products on the market today that must not be used because they can damage equipment.

The most important recommendation is to contact the equipment manufacturer for guidance. The manufacturer does not want their equipment to fail and potentially cause additional damage or possibly injure people. The handiest tool that we all have these days is our smartphone cameras. Once you have contacted the right technical person, you can send photos.

Molded-case circuit breakers are an example of equipment that cannot easily be cleaned and placed back into service. Many people may view them as sealed units that water cannot enter. That is not the case.

As noted in GD-1, “In molded-case circuit breakers and switches, such exposure can affect the overall operation of the mechanism through corrosion, through the presence of foreign particles, and through loss of lubrication. The condition of the contacts can be affected, and the dielectric insulation capabilities of internal materials can be reduced. Further, some molded-case circuit breakers are equipped with electronic trip units, and the functioning of these trip units can be impaired.”

Simply cleaning off the outside will not protect the interior of the breaker from water that has entered the housing, nor will it prevent long-term corrosion of contacts or the springs that are part of the tripping mechanism. Deposits of contaminated material on insulating surfaces can lead to arcing and failure. Any restoration should begin as soon as possible to prevent further corrosive damage.

Is it covered by insurance?

Insurance losses are typically divided into property damage and business interruption. Property damage is the direct damage to the equipment, which is subject to deductibles. Coverage of equipment may also be subject to depreciation. When equipment in a commercial or industrial facility is damaged, some part of the production is interrupted. So now, there is damage that needs to be fixed, and the revenue machine is no longer operating.

The most common sources of water damage, broken pipes and sprinkler water spray, are usually covered by fire and extended coverage insurance. Flood water is not. Damage from floods and surface water are usually covered by a special flood insurance policy.

In commercial and industrial properties, the damage to equipment is not the end of the loss and resulting insurance claim. The company may not be able to continue to make its products. The loss grows with each passing hour or day that it is not able to resume operations. Business interruption insurance—typically an add-on—covers the financial loss from the inability to resume operations. There may be a variety of coverage levels and deductibles. For example, fire insurance covers loss of business due to fires. There are also boiler, machinery coverage and all-risk coverage. However, if something happens that does not include the related property damage coverage, such as a flood insurance, there would typically not be coverage for business interruption.

What doesn’t business interruption insurance cover?

From a purely production standpoint, it may make the customer whole. However, in this age of just-in-time manufacturing, every part of the supply chain downstream depends on the parts of the supply chain upstream. If a supplier upstream is not able to deliver products for an extended period, the natural course of action is to find a new supplier who can meet the demand. While business interruption insurance may cover the loss of income, it will not cover the loss of a customer, and it cannot cover the loss of a reputation.

We can’t only be concerned about property damage and business interruption. Equipment must be capable of safe operation. Internal contamination of a circuit breaker may cause it to explode when it is called on to interrupt a fault, creating a worse situation for restoration. Worse yet, operation may injure people working in the area.

Mitigating the loss

If equipment must be in a flood zone, elevation is advisable to keep water out. This equipment might still be subject to corrosion if flood waters reach it.

Some water-damaged equipment can be cleaned or repaired. The question is whether it should be. There are several considerations. Will it delay a return to service? Will it result in a less-reliable service?

If there is a long lead time to repair or replace certain equipment, spare parts or replacement equipment should be considered to facilitate a shorter downtime.

Every business should analyze its vulnerability to risk to determine what their Achilles’ heel is. What are those production areas that are critical to continued operations, and what are the lead times for obtaining and installing replacement equipment?

Redundant equipment or replacement spare parts can be a significant expense. However, if the lead time for replacement equipment is long, keeping spares on hand might be the key to survival of the business. In some cases where spares are available and the equipment can be repaired, the spares can be put into service while the damaged equipment is being repaired.

About the Author

Mark Earley

Mark Earley, P.E., is an electrical engineer. Retired from the National Fire Protection Association, he was secretary of the National Electrical Code Committee for 30 years and is president of Alumni Code Consulting Group.

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