Accounting for Flooding During Installation

Back in 2017 Atlantic hurricane season was catastrophic, with three major hurricanes making landfall on either the continental United States or U.S. territories. When severe storms like those hit, you like to think your business is prepared.

Share This Article

Back in 2017 Atlantic hurricane season was catastrophic, with three major hurricanes making landfall on either the continental United States or U.S. territories. When severe storms like those hit, you like to think your business is prepared. The power goes out, but it's only a matter of moments before the backup generator kicks in. Then after 30 seconds, there is still nothing. When you go to find out why, the answer becomes obvious. A generator cannot protect your property if it is submerged in floodwaters — an unfortunate consequence of many tropical storms.

National Fire Protection Association (NFPA) 110 and 37 standards provide code-required guidelines for correct generator installation, and these address how to plan for potential flooding situations. NFPA 110 states that for natural conditions, Emergency Power Supply System (EPSS) design should consider the "100-year storm" flooding level or the flooding level predicted by the sea, lake, and overland surges from hurricanes. This means locating the generator in an area that mitigates flooding potential, such as on the roof or on a raised platform to situate it above the flood plain.

While the NFPA 110 standard was put into place in 1985, the standards have not always been fully followed. On Aug. 29, 2005, Hurricane Katrina pummeled the city of New Orleans. Power outages triggered standby power systems. However, the levees protecting the city from the hurricane failed. According to the Federal Emergency Management Agency (FEMA), this resulted in the flooding of 80% of the city. Many standby generating systems failed immediately as a result.

That's when the industry began to take notice. In 2008, the National Electrical Code (NEC) added section 708, "Critical Operations Power Systems". NEC 708 reiterated that equipment must be located above the 100-year floodplain. The flood-related requirements call for a number of actions, including the following:

  • Using available flood hazard information for the siting, design and construction of buildings.
  • Designing and constructing structures to withstand anticipated flood loads.
  • Using flood-damage-resistant materials below the design flood elevation.
  • Mounting the unit no less than 2 ft. above ground or above the point identified as the prevailing highest weather level mark.

"Once the generator is flooded, the alternator windings may become compromised, and internal engine corrosion begins," said Michael Kirchner, senior sales training manager for Generac Industrial Power. He said that in the case of flooding, most businesses will file for an insurance claim and have to go through the process of buying and installing a new unit, selling the generator at salvage value to third-party firms that will try to reclaim the equipment.

Severe weather doesn't affect Generac Industrial Power systems. Kirchner said Generac generators are designed to start and run in any kind of weather. They are listed to the Underwriters Laboratories (UL) 2200 standard, a sign that the gen-set has been evaluated and approved by a nationally recognized testing laboratory.

A generator manufacturer only receives approval to apply the listing after a rigorous review and identification of all the unit’s components. Part of the UL2200 examination is a rain test, which is performed to simulate a heavy rain using specific water nozzles, water pressure, flow rates and direction of spray onto the gen-set enclosure while it is operating at maximum airflow through the enclosure.

After the water is sprayed onto the enclosure for one hour per side, the gen-set is shut down, and any amount of water accumulation inside the gen-set is evaluated for potential electrical hazards. The alternator is also hipot tested to ensure the electrical windings have not been damaged and to check for other electrical shorting by any ingress of moisture.

Generac makes all of its own enclosures up through 2 MW, but not everyone does. Some manufacturers imply the complete generator system is UL 2200 approved when in fact they are utilizing a UL-listed open gen-set and then applying a third-party enclosure, skipping the important UL2200 rain test process. Generac makes factory enclosures for all of it products to ensure the highest degree of factory testing and genset reliability.

Businesses should also consider fuel delivery when planning to install a backup power system. Generators require sufficient fuel supplies for extended running during storms.

"Businesses may not be able to get more diesel fuel in the event of a storm because of flooding," said Kirchner. "And long-term outages often expose fuel quality issues when the addition of fresh diesel fuel stirs the fuel contaminants on the bottom of the tank."

On-site diesel storage tanks are typically sized to provide 12 to 72 hours of run time. According to the NFPA 110, fuel tanks that are subject to temperature variations can experience accelerated fuel degradation, especially if the tanks are outside and above ground. The presence of water can lead to microbiological contamination and growth, which in turn can lead to general or pitting corrosion of steel tanks and components, possibly resulting in filter plugging, operational issues or a hydrocarbon release into the environment.

NFPA 110 also requires fuel to be tested annually and remediated as necessary. Kirchner said that diesel generators must have a preventative fuel maintenance program to be deemed reliable.

By comparison, natural gas generators avoid those fuel supply and maintenance issues. The natural gas pipeline network is robust. According to a 2013 report by Massachusetts Institute of Technology's Lincoln Laboratory, natural gas distribution systems operate at a reliability rate exceeding 99.999%, with the exception of seismically active areas. Incidentally, that makes the natural gas distribution system approximately one-thousand times more reliable than a single-engine generator set, which is typically assumed to be 99% reliable.

In any case, Kirchner advises to always run the generator before a storm hits and transfer the facility load onto it to validate that it is working properly.

"Generac recommends generators be exercised weekly," he said. "If the application will allow it, put facility load on the generator monthly. That will create the highest sense of reliability and ensure that the generator is up to the task of running the facility."

By running necessary exercises and tests on the generator, as well as following all of the laws and regulations, your Generac generator will be ready to tackle any storm and ensure you are too.