Hurricane Prep for Commercial Electrical Systems in Florida

Most hurricane checklists for businesses talk about shutters, sandbags and backing up the server. Those matter. But in our experience, the thing that decides whether a commercial building reopens in two days or two weeks is usually electrical. Is there backup power? Does the transfer switch work? Did water get into the switchgear? Was the restart done safely?

Here is how we think about hurricane prep for commercial electrical systems in South Florida. Hurricane season runs June 1 through November 30, and most of this list should be done before it starts.

Before the season: generator and transfer switch

If your building has a generator, it should be tested well before June. NFPA 110, the Standard for Emergency and Standby Power Systems, calls for monthly exercise under load and, for diesel generators that do not run heavily enough during those monthly tests, an annual load bank test. Do that test in the spring. In August, load banks and technicians are booked solid.

Beyond the load test, check the starting batteries and the battery charger. Dead batteries are the most common reason a generator fails to start. Check the fuel. Diesel picks up water in our humid climate and can grow microbial contamination. A fuel test, and polishing if needed, is worth doing every year. Confirm how many hours of runtime you have at the expected load and how you will get more fuel after a storm. Fuel deliveries get scarce.

Exercise the automatic transfer switch. Inspect it for heat damage, loose connections and contact wear. A generator that runs perfectly is useless if the transfer switch sticks.

Before the season: if you do not have a generator

Not every building needs a permanent generator, but every business should know what it would do without power for several days. Some owners install a portable generator connection, a manual transfer switch or a docking station so a rental generator can be connected quickly. That has to be designed and installed properly. Backfeeding a building through an outlet is dangerous to you and to utility workers.

If you have critical loads, such as refrigeration, medical equipment, servers or security systems, a permanent standby generator with an automatic transfer switch is the reliable answer. Sizing it right matters. Too small and it will not carry the load. Too large and it will run lightly loaded, which causes its own problems.

Before the season: inspect the electrical gear

Have an infrared scan done on the main switchgear, distribution panels and major connections. Loose or overheating connections show up clearly on a thermal camera. NFPA 70B, which became a full standard in its 2023 edition, puts thermography and other electrical maintenance on a regular cycle. Fixing a hot connection in April is much better than having it fail when the building is running on generator power.

Look at outdoor electrical equipment: disconnects for rooftop units, exterior panels, meter cans, lighting and signage. Rust, missing covers and failed gaskets let water in. In the High Velocity Hurricane Zone, which covers Broward and Miami Dade under the Florida Building Code, outdoor equipment also needs to be anchored for very high wind loads. That includes rooftop units and condensers, which are often wired through roof penetrations that leak if the equipment shifts.

Before the season: think about flooding

Where is your main electrical equipment? Many older South Florida buildings have switchgear, transformers or generators at or below grade, sometimes in parking garages. If the building is in a flood zone, ask whether critical equipment could be elevated or protected. The Florida Building Code has flood resistant design requirements for new work in flood hazard areas, but existing buildings were often built before those standards.

Document where the shutoffs are and who is allowed to operate them. In a storm, the person who knows how to shut down the main may not be in the building.

Surge protection

Hurricanes bring lightning and wild utility swings when power drops and comes back. Surge protective devices at the service entrance and at panels feeding sensitive equipment help protect electronics, controls and HVAC equipment. Surge protection is not a guarantee, but it is inexpensive compared to replacing control boards in a dozen rooftop units.

When a storm is coming

Once a storm is in the forecast:

• Top off generator fuel and confirm delivery arrangements

• Run the generator under load to confirm it is ready

• Shut down and unplug sensitive equipment that is not on backup power

• Secure loose items on the roof that could damage equipment or become projectiles

• If the building may flood, consider shutting off power to equipment in flood prone areas before water arrives, following your plan

Do not ask staff to work on electrical equipment during the storm.

After the storm: restart safely

This is where people get hurt. After a hurricane, assume equipment that was exposed to water is damaged until someone qualified says otherwise.

Electrical equipment that has been submerged or soaked, especially by salt water, generally needs to be inspected and often replaced. NEMA publishes guidance called Evaluating Water Damaged Electrical Equipment that lists which components should be replaced after water exposure and which might be reconditioned. Breakers, fuses, transfer switches, motor controls and many other components are on the replace list. Simply drying them out and turning them on is a fire risk.

Check for structural damage to the electrical service, damaged meter equipment or service masts, and fallen lines. Downed lines belong to the utility. Stay away from them and report them.

When utility power returns, the generator and transfer switch should transfer back normally. Watch for problems. Restart HVAC and large motors in stages, not all at once.

If your building needed electrical repairs after the storm, permits and inspections may be required before the utility will reconnect service. Your electrical contractor can tell you what applies.

A plan beats a checklist

The buildings that come through storms best have a written plan: who is responsible for what, where the shutoffs are, how the generator is fueled, and which contractor to call. They test the plan before June.

Get ready before June

We test generators, service transfer switches, perform infrared scans, and handle electrical repairs and safe restarts after storms across Broward, Miami Dade and Palm Beach. See our generator services, then call 954.577.7923 or request service.