Commercial Electrical Service, Switchgear and Three-Phase Power in South Florida

Commercial service and distribution

From the utility transformer to the tenant panel

What the Service Entrance Actually Includes

Every commercial building has the same chain, whatever its size: the utility's transformer, the service conductors, the metering, the service disconnect, and the distribution equipment that splits power out to the floors, tenants and equipment. On a small retail bay that chain may be a meter, a main breaker and one panelboard on a wall. On a mid-rise or a shopping center it is a transformer pad, a switchboard or switchgear lineup, a meter center and a feeder to every tenant space.

The names get used loosely, so it helps to be precise about what is being bought:

• Panelboards are the familiar commercial electrical panel: breakers in a cabinet, fed from upstream, serving branch circuits. A tenant space usually has one or more.
• Switchboards are free-standing sections that take the service or a large feeder and distribute it to panelboards, mechanical equipment and meter stacks. Most mid-size commercial services in South Florida land on a switchboard.
• Switchgear is heavier, more serviceable distribution equipment, typically with draw-out breakers in separate compartments. It shows up on larger services, critical loads and buildings where the engineer wants maintenance without a full outage.

The difference matters for space, cost, lead time and how the equipment is maintained. Our guide what is switchgear goes further on the distinction. For small services and single-tenant spaces, the panel and service upgrade page covers the simpler end of the same work.

208Y/120 V or 480Y/277 V: Choosing the Three-Phase Service

Almost every commercial building of any size gets a three-phase service. The decision that shapes everything downstream is the voltage.

208Y/120 volt

This is the common choice for offices, retail, restaurants and small mixed-use buildings. Receptacles, small equipment and most kitchen appliances run directly from it, so the building needs no step-down transformers. The trade-off is current: at 208 volts, large loads need bigger conductors and bigger breakers than they would at 480.

480Y/277 volt

Larger buildings, warehouses, big chilled-water or rooftop HVAC plants and buildings with long feeder runs usually go to 480Y/277. Motors and mechanical equipment run on 480, commercial lighting often runs on 277, and dry-type transformer installation inside the building steps power down to 208Y/120 for receptacles and small loads. Higher voltage means less current for the same power, which keeps feeders and switchgear smaller.

FPL's Electric Service Standards list both 120/208 V and 277/480 V wye services among the secondary voltages it serves from padmount transformers. Which one a project gets is an engineering decision made with the utility, based on the load, the equipment schedule and what the local distribution can supply.

If the question is whether an existing space has three-phase at all, or whether a business needs it, read three-phase power: do you have it, and do you need it before signing a lease. The answer is often no, and a 3 phase installation into a single-phase unit starts with the utility, not the panel.

Service Sizing and Load Calculations

The service size comes from a load calculation, and on a commercial project that calculation belongs to the engineer of record. KRW Electric works alongside the engineer on design-assist: confirming the equipment schedule with the owner and the other trades, flagging loads that are missing (walk-in coolers, EV chargers, future tenants, a kitchen that grew), and checking that the distribution layout can actually be built and maintained in the room it has been given.

On an existing building, the calculation should be backed by what the building actually draws. Utility demand history tells you far more than a nameplate count.

Things worth settling before the design is frozen:

• Whether the service should be sized for known tenants only, or with capacity for spaces still unleased.
• Where future loads (EV charging, added HVAC, a second kitchen) will land, and whether spare breaker positions or a spare section is cheaper now than a second service later.
• How many meters are needed and whether tenants will be separately metered.
• Whether life-safety and standby loads need their own distribution.

If the building is already running out of capacity, when a business outgrows its electrical service covers the signs and what a commercial service upgrade actually involves.

Utility Coordination: FPL, Homestead and Lake Worth Beach

A new service or a service upgrade is a joint project with the utility, and the utility controls a large part of the schedule. Most of Miami-Dade, Broward and Palm Beach is served by FPL. Some cities run their own electric utility with their own process, including Homestead (HPS Energy) and Lake Worth Beach. Confirm the utility before anyone designs a service.

FPL handles commercial new service and service upgrade requests through its construction project portal, and says that planning a new project can take a few months, so it asks customers to contact it early. Its published process runs from application to an assigned FPL project manager, then plan and design, pre-construction and construction, and finally the new account. The same portal handles service upgrades and relocations, temporary construction power, disconnect and reconnect appointments, and fault current and service availability letters.

Details from FPL's Electric Service Standards that affect the electrical design:

• Metering. FPL uses self-contained meters for smaller services and generally switches to current transformer (CT) metering above the self-contained meter rating. FPL furnishes the CTs; the customer furnishes and installs the instrument-transformer-rated enclosures and cabinets, and every meter socket must be on FPL's approved meter enclosure list.
• Meter banks and meter centers. For multi-tenant buildings, the standards require a main disconnect ahead of the meters when more than six meters are grouped, and each meter position must be clearly identified with the address it serves before FPL will energize it.
• Downtown Miami. Where a service is fed from the City of Miami Downtown Network grid, FPL requires the service equipment to be ahead of the meter, which changes the lineup.
• Vaults. FPL states that it no longer allows new sub-grade vaults, so older buildings adding load from a below-grade vault may need a new grade-level service point.
• Energizing. FPL's service application checklist lists a site plan, electrical load information and plans, an easement where FPL equipment sits on the property, and the final city or county electrical inspection before permanent service.

For how the utility side lines up with the construction schedule, see the new commercial electric service and utility timeline. The permit side is on commercial electrical permits and inspections.

Why Switchgear and Transformer Lead Times Run Long

Commercial distribution equipment is generally built to order, not pulled from a shelf. A switchboard is assembled to a specific set of ratings: ampacity, voltage, short-circuit rating, breaker types, metering section built to the utility's requirements, and the physical layout of the room. That creates a chain of steps before anything ships:

1. The engineer's design and the utility's service information are settled.
2. The supplier prepares submittals (shop drawings) for that exact lineup.
3. The engineer reviews and approves them; comments send them back around.
4. Only after release does the order enter the manufacturer's production schedule.

Every change after release, such as a bigger main, an added section or a different metering arrangement, can restart part of that chain. Transformers and larger breakers have their own supply constraints on top of that.

The practical response is sequencing, not hope: get the utility conversation and the load calculation done early, push submittals to approval quickly, and hold the design steady once equipment is released. Ask the supplier for current lead times at the time of order, because they move, and build the schedule around the quoted date rather than a remembered one.

Equipment Location, Working Space and the Meter Room

Where the equipment goes is decided early and is hard to change. The National Electrical Code's working-space rules in NEC 110.26 set minimum depth, width and headroom in front of electrical equipment and, for large equipment, require access at both ends of the working space. The code itself is published by NFPA as NFPA 70, which the Florida Building Code adopts by reference; check with the building department which edition applies to your permit.

FPL adds its own requirements for meter rooms: its Electric Service Standards say a meter room must not be used for storage and set mounting heights for meters. A meter room that doubles as a storage closet will be a problem at inspection and every time the meters are read.

On South Florida buildings, rooftop switchgear feeding mechanical plant is common, and so are shared service rooms with meter banks and tenant disconnects. You can see both in our project gallery. Each location brings its own questions: roof access and equipment supports, weather protection, and the route of the feeders back down the building.

Flood Zones, Salt Air and Hurricane Wind

Location in South Florida is also a flood question. FEMA's guidance on building electrical systems treats meters, service equipment and distribution panels as primary components that stop the whole building when they flood, and names elevating them in place or relocating them to an upper floor as the most effective mitigation.

Local rules decide the minimum. Flood zones, base flood elevations and elevation certificates are handled through the floodplain management program of the county or city with jurisdiction (Miami-Dade County floodplain management, for example). Where local ordinances require meters at or above base flood elevation, FPL requires the customer to provide a permanent means of access to them.

Salt air is the other enemy. Equipment near the coast corrodes faster, so enclosure ratings, hardware and conduit materials are worth specifying for the environment, not just the load. In Miami-Dade and Broward, rooftop and exterior equipment also sits inside the High-Velocity Hurricane Zone; see commercial electrical permits for what that means at plan review.

Service Changes on Occupied Buildings

Replacing a service or switchboard in a building that is open for business is mostly a planning exercise. The outage itself can often be kept to one planned window if the work before it is done properly:

• Survey and label first. Trace what every existing feeder serves before anything is disconnected. Old buildings rarely match their panel directories.
• Pre-build the new equipment. Set, terminate and test as much as possible while the old service stays live.
• Book the utility. The utility disconnect and reconnect is an appointment made through the utility, and the whole shutdown hangs on it.
• Protect what cannot go dark. Refrigeration, life-safety systems, elevators, data rooms and tenants with critical equipment need temporary power or a sequence that keeps them up.
• Tell the tenants. Written notice of the window, what will be off, and who to call.

Our post on getting electrical work done without closing the business covers the owner side of that planning.

What KRW Electric Does on Service and Distribution Work

KRW Electric (Florida electrical contractor license EC13012832) installs commercial services and distribution: service entrance equipment, switchboards, panelboards, meter banks and meter centers, CT cabinets, feeders, in-building step-down transformers and the tenant distribution that hangs off them. We coordinate the electrical side with the utility, the engineer of record and the general contractor, and we pull the electrical permit for the scope we install.

We are not the engineer of record and do not produce engineered drawings. Short-circuit, coordination and arc flash studies are engineering work; our guide to NFPA 70E and arc flash for building owners explains what those studies are and why the labels matter.

Service work usually sits inside a larger project. See commercial electrical services for the full scope, new construction electrical for ground-up buildings, and commercial remodel and tenant improvement when the service change is part of a build-out. Chargers and lighting often drive the capacity question: see commercial EV charging and commercial lighting and controls.

Planning the work? Send the drawings or a description through our contact page or call (305) 359-7312.