What Electrical Work Is Needed for a Generator Installation?

A typical home standby generator install in Jacksonville includes specific electrical scope: an automatic transfer switch (ATS), wiring between the generator and the ATS, integration with your existing main panel, grounding and bonding to existing electrical infrastructure, and breaker labeling. Most installs don't require a full panel upgrade — but some do, and recognizing when that's needed is part of the on-site quote.

Here's the line-by-line of what the electrical scope looks like for a typical Jacksonville-area home standby install.

The automatic transfer switch (ATS)

The ATS is the most important electrical component. It's a heavy-duty switch that physically connects your home to either the utility grid OR the generator — never both simultaneously. This prevents backfeed (which kills lineworkers) and protects equipment.

ATS sizing: matched to your generator and your main panel ampacity. Common sizes:

• 100A — older Jacksonville homes (Riverside, Avondale, smaller bungalows)
• 200A whole-home — most modern homes (Mandarin, Nocatee, Pablo Creek, etc.)
• 400A whole-home — larger homes (Ponte Vedra Beach, Atlantic Beach, larger Mandarin lots)

ATS placement: typically adjacent to or near your existing main panel. The transfer switch sits between the utility service entrance and your home's panel, on the utility side of all branch circuits.

ATS type — "service entrance" vs. "non-service entrance":

• Service entrance ATS replaces your existing main breaker with the transfer switch acting as the main disconnect. Cleaner install, fewer components.
• Non-service-entrance ATS sits next to the existing main panel as a separate enclosure. Useful when the main panel is in a difficult location.

We default to service-entrance for most Jacksonville installs because it's a cleaner electrical layout. Non-service-entrance happens when the main panel is in a finished basement or behind a wall that can't be easily modified.

Wiring from generator to ATS

Heavy-gauge conductors carry power from the generator to the ATS:

• 22kW generators typically use 1/0 AWG conductors (or larger)
• 26kW generators use 2/0 AWG or larger
• Run length matters — longer runs require larger gauge to compensate for voltage drop

These conductors run in conduit (rigid PVC or metal, depending on local code interpretation) from the generator's connection point to the ATS. Buried runs go in PVC; above-ground runs use metal. Most Jacksonville installs have a 10-30 foot run between unit and panel.

Grounding and bonding

Code-required grounding and bonding for a generator install:

• Ground rod at the generator (some configurations) or bond to existing ground electrode system
• Equipment grounding conductor (separate from neutral) running with the power conductors
• Neutral bonding — done at the service entrance, NOT at the generator. Wrong neutral bonding is a common DIY install mistake and a real safety issue under fault conditions.
• All metal conduit and enclosures bonded to the ground system

The grounding and bonding work is what every electrical inspector spends the most time checking. Done right, fault currents have a clear path. Done wrong, a fault during operation can energize what should be ground.

Panel work

Most installs include some panel-side work:

• Breaker labeling — every circuit on the panel labeled clearly. NEC code, but also genuinely useful — many older Jacksonville panels have unclear or missing labels, and the install team rebuilds them.
• Conductor torque — every panel connection torque-checked to manufacturer spec. Loose connections are a leading cause of panel fires; the inspection process verifies this.
• Surge protection — many installs add whole-home surge protection at the panel. Optional, but cheap insurance against lightning surges (Jacksonville is in one of the highest lightning strike zones in the U.S.).

When panel upgrades are needed

About 20-30% of homes we quote in Jacksonville need some kind of panel-related work beyond the basic install:

Service upgrade. Some older homes still have 100A service. With AC, electric water heater, and modern appliance loads, 100A is genuinely undersized — the panel itself runs hot. A generator install on a 100A panel often means upgrading service to 200A. Cost: $1,500-$3,500.

Sub-panel addition. When the main panel is full (no spare breaker spaces) and a generator install requires new breaker positions, a sub-panel can be added rather than replacing the entire main panel. Cost: $800-$1,800.

Old panel replacement. Federal Pacific, Zinsco, and some older Pushmatic panels have known reliability issues. If your home has one of these (common in 1960s-70s Jacksonville-area homes), we typically recommend replacement before generator install. Cost: $1,500-$3,000 for the panel + $500-$1,000 for the install integration.

We surface panel-related issues during the on-site quote, not after install begins.

Whole-home vs. selected-circuit transfer

Two install patterns:

Whole-home transfer:

• Transfer switch replaces or sits at main service entrance
• All circuits in the home are eligible to run on generator
• Generator must be sized for full home load (or use load management to shed non-critical circuits during overload)
• Simpler install for the homeowner — no thinking about "which circuits do I want"

Selected-circuit transfer:

• Transfer switch only carries specific circuits (kitchen, master bedroom, fridge, etc.)
• Other circuits stay tied to utility — they don't have power during outage
• Allows smaller generator (10-14kW for a home that would otherwise need 20kW)
• More wiring work to break out specific circuits

Most Jacksonville home standby installs we do are whole-home transfer. Selected-circuit makes sense for budget-constrained installs or homes where the main panel layout doesn't accommodate a whole-home transfer cleanly.

Load management

For 22kW+ installs on homes near the unit's capacity, load management is a smart accessory:

A load management module monitors total demand on the generator. When demand approaches the unit's capacity, the module sheds non-critical loads (typically: pool pump, EV charger, electric water heater) until demand drops back. The shed loads come back on automatically once capacity allows.

This is what allows a 22kW generator to run a home that would otherwise need a 26kW unit — the EV charger and pool pump are off during outages anyway, so shedding them automatically is no real loss to the homeowner.

The labor breakdown of install day

Of the 6-10 hours an install takes on-site, the electrical work breaks down roughly:

• ATS installation: 1-2 hours
• Conductor pulling and connection: 2-3 hours
• Panel integration and breaker work: 1-2 hours
• Grounding and bonding: 1-2 hours
• Final wiring and breaker labeling: 0.5-1 hour
• Functional testing: 0.5-1 hour

The other 2-4 hours of the install day is gas tie-in, pad placement, unit set, startup, and walkthrough.

What's not included (typically)

Things some homeowners assume are part of the electrical scope but aren't:

• Adding new circuits or moving existing circuits (separate scope)
• Outlet additions or modifications
• Smart home integration beyond the manufacturer's app
• Solar / battery integration (separate complexity, separate quote)

Each of these is a real project on its own — we can quote them, but they're outside the standard generator install scope.

Bottom line

The electrical work in a Jacksonville home standby install is well-defined: ATS, conductors, panel integration, grounding, labeling. The variable is whether your existing panel needs work first. About 1 in 4 quotes includes some panel-related scope; the rest are clean integrations into existing infrastructure. We surface this during the on-site quote so there are no surprises on install day.