Automatic Transfer Switch Cost $500 to $2,800 Installed.
The second-largest line item on most generator installs, behind the generator itself. The switch is what detects a utility outage, isolates the home from the grid, and connects the generator to the home panel. It is also the component most often misquoted and the easiest place for installers to hide margin.
ATS Cost by Amperage and Type
| Type | Amps | Switch MSRP | Install Labour | Total Installed | Used For |
|---|---|---|---|---|---|
| Sub-panel | 100 | $300 - $500 | $200 - $400 | $500 - $900 | 7-10 kW essentials-only |
| Service-entrance | 100 | $500 - $800 | $400 - $700 | $900 - $1,500 | 10-14 kW small homes |
| Service-entrance | 200 | $700 - $1,200 | $500 - $1,000 | $1,200 - $2,000 | 18-22 kW typical residential |
| Service-entrance | 400 | $1,300 - $1,800 | $700 - $1,400 | $1,800 - $2,800 | 26 kW+ and large estates |
| Service-entrance | 600 | $2,200 - $3,000 | $1,000 - $1,800 | $3,200 - $5,000 | Commercial / 48 kW+ residential |
Switch MSRP from Generac RTS / RXSC product pages, Kohler RXT, May 2026.
Service-Entrance vs Sub-Panel: the Real Trade-Off
The service-entrance vs sub-panel decision is the single biggest cost lever in transfer switch selection. A service-entrance ATS sits in the electrical service path between the utility meter and the home's main panel, switching the entire home over to generator power as one unit. A sub-panel ATS sits downstream of the main panel and feeds only the circuits wired to it (typically 8 to 16 essential circuits), leaving the rest of the home dark during an outage.
The cost difference is roughly $700 to $1,200 in the switch hardware and another $300 to $600 in labour. The sub-panel installation is faster (no meter cut, no service conductor re-pull, no utility coordination appointment) and the inspection is simpler (the work is entirely on the load side of the meter, which the utility cares about less). Total install time on a sub-panel job is roughly 4 to 6 hours; service-entrance is 8 to 12 hours typically.
The user-experience difference is large. With a sub-panel ATS during an outage, only the wired circuits work. The homeowner must remember which outlets are on the standby panel, cannot use the dishwasher or the dryer or the central AC, and has half a house that goes dark every time the lights go out. With a service-entrance ATS, every outlet works, every switch works, the AC runs, the dryer runs, the cooktop runs (gas-fired), and the outage is largely invisible except for the generator running quietly outside. The premium for the service-entrance install is buying that no-thought continuity.
For installs where the generator is undersized for the whole home, sub-panel makes more sense because the load management is hard-coded by the wiring (only the standby circuits ever see generator power, so the generator cannot be overloaded). For installs where the generator is sized to the home, service-entrance is the right answer because there is no reason to leave half the home dark when the generator can power it all.
Brand-Compatible ATS Models
Each generator brand has its own ATS line. The switches are technically interoperable in many cases (the relay-and-controller communication is fairly standardised), but the warranty terms generally require a matched brand. Mixing a Generac generator with a Square D transfer switch usually voids the generator warranty. For practical purposes, the rule is: use the manufacturer's matched ATS line.
Generac RTS / RXSC
RTS is the standard residential line, 100A to 400A. RXSC is service-entrance. The 200A RXSC is the volume model for 18 to 22 kW Guardian installs. MSRP $700 to $1,200.
Kohler RXT
RXT is the residential line, 100A to 400A. RXT-AFS adds advanced load management. Standard pricing roughly $200 to $400 over equivalent Generac because Kohler builds the enclosure to a higher finish standard. MSRP $900 to $1,500 for 200A.
Cummins RA
RA residential transfer switch line, 100A to 400A. Built on commercial PowerCommand architecture so the controller is more capable than competitors. MSRP $800 to $1,400 for 200A. Worth specifying with the Cummins generator for warranty alignment.
Briggs SymphonyII
SymphonyII transfer switch line, 100A to 200A primarily (limited 400A options). Built with load management integration as standard. MSRP $600 to $1,100 for 200A, lowest of the four majors.
Load Management: When the ATS Becomes a Smart Switch
Modern ATS units increasingly include or support load management features that allow the controller to selectively shed non-essential circuits when the generator approaches its capacity limit. The most common use case is the electric water heater and electric dryer: the ATS sheds both when the central AC compressor cycles on, then restores them once the AC settles into steady-state running.
Generac's Smart Management Modules (SMM) are sold as add-ons to the RXSC switch, $150 to $250 per module installed. Each module controls one circuit and the system supports up to 8 modules. Kohler's load management is integrated into the RXT-AFS at extra cost ($300 to $500 over standard). Cummins integrates load management as standard on the RA series. Briggs SymphonyII includes basic load management out of the box.
Load management lets a homeowner buy a smaller generator than the home's theoretical peak load would otherwise require. For a home with calculated 22 kW peak demand, load management often allows an 18 kW unit to cover the install effectively, saving $1,500 to $2,500 on the unit. The trade is that some appliances cycle off briefly during peak surges, which can be annoying if the dishwasher mid-cycle pauses for 90 seconds while the AC compressor starts. For most homeowners the trade is worthwhile.
FAQ
How much does an automatic transfer switch cost?v
$500 to $2,800 installed depending on amperage and type. A 100A sub-panel ATS runs $500 to $900 installed. A 200A service-entrance ATS (the standard residential spec for 18 to 22 kW generators) runs $1,200 to $2,000 installed. A 400A service-entrance ATS for 26 kW and larger runs $1,800 to $2,800 installed.
What size transfer switch do I need?v
Match the switch to your main service panel rating, not the generator size. If you have a 200A main service panel, use a 200A ATS even if the generator is only 14 kW. If you have a 400A service panel (common in larger newer homes), use a 400A ATS. The switch must carry the full load the panel is rated for so utility power passes through normally.
Service-entrance vs sub-panel ATS: what is the difference?v
Service-entrance ATS sits between the utility meter and the main panel, switching the whole home over to generator. Sub-panel ATS sits downstream of the main panel and feeds only selected circuits (lights, fridge, well pump, furnace), leaving the rest of the home dark during outages. Service-entrance is the standard for 18 kW and larger generators. Sub-panel is the cheaper option for smaller 7 to 14 kW partial-coverage installs.
Can I install a transfer switch myself?v
Legally, no in most U.S. jurisdictions. ATS installation requires an electrical permit, which requires a licensed electrician. The work involves cutting the meter and re-pulling service conductors, which requires utility coordination. Beyond legality, mistakes have catastrophic consequences (backfeed into utility lines can kill linemen working to restore power). Always use a licensed electrician for transfer switch installation.
Why are some installers quoting $3,000+ for the transfer switch?v
Two legitimate reasons and one red flag. Legitimate: a 400A switch with full electrical panel upgrade can reach $3,500. Or the install requires extensive conduit work, meter relocation, or trenching. Red flag: some installers bundle the switch and labour with hidden markup, making the switch look expensive to disguise margin elsewhere. Always ask for the switch model number and look up MSRP at the manufacturer site; if installed price is more than 1.6x MSRP, ask for a labour breakdown.
Related
Installation labour
All install lines, not just the switch.
Concrete pad cost
$300 to $800 the right way.
Install guide hub
Permits, ATS, pad, gas, electrical step by step.
22 kW context
Where 200A ATS is the standard spec.
26 kW context
400A ATS more common at this size.
Ways to save
Switch sizing, sub-panel option, manufacturer rebates.