Load Center vs. Whole House Transfer Switch
A load center transfer switch powers a limited number of pre-selected circuits during a generator outage. A whole house transfer switch powers your entire electrical panel, every circuit, with no selection or compromise required. The choice between them depends on your generator size, budget, and how much of your home you want to protect during an outage.
Load Center Transfer Switches
How They Work
A load center transfer switch (sometimes called a managed transfer switch or load-managed ATS) contains its own small breaker panel with 8 to 16 circuit spaces. During installation, your electrician moves the circuits you designate as “essential” from your main panel into the load center panel. During normal operation, these circuits run on utility power passed through the transfer switch. During a generator outage, only the circuits in the load center receive generator power. Your remaining circuits (the ones left in the main panel) stay off until utility power returns.
Advantages
Load center switches cost less than whole house switches. They pair well with smaller, less expensive generators (14kW to 18kW) because the generator only needs to serve the selected circuits rather than the full panel. They provide good protection for essential systems at a lower total project cost.
Limitations
You must decide in advance which circuits to protect. If you forget to include a circuit (such as a home office outlet you did not think about when the system was installed), that circuit has no power during an outage. The number of available circuit spaces (8 to 16) limits your options. Some large loads like central air conditioning may not fit within the available capacity of a smaller generator, even if the circuit is included in the load center.
Whole House Transfer Switches
How They Work
A whole house transfer switch (typically rated at 200 amps for most residential installations) installs between the utility meter and your main breaker panel. It transfers your entire panel from utility to generator power. Every circuit in your home receives power during an outage, exactly as if the utility were still on. There is no circuit selection, no load management, and no compromise.
Advantages
Complete coverage means you never discover during an outage that you forgot to include a critical circuit. There is no rewiring of individual circuits during installation (the switch handles the entire panel). The generator powers everything including central HVAC, which is essential for comfort and health during extended outages. Whole house switches are simpler to install from a wiring perspective because individual circuits do not need to be relocated.
Considerations
Whole house switches require a generator large enough to handle the full panel load (typically 22kW or larger for a 200-amp panel). The combined cost of a larger generator plus a whole house ATS is higher than a smaller generator with a load center switch. However, many homeowners find the peace of mind of complete coverage justifies the additional investment.
Which One Should You Choose?
Choose a load center transfer switch if your budget is the primary constraint and you are comfortable selecting which circuits to protect, you are pairing with a smaller generator (14kW to 18kW), or your home has modest power requirements and you can cover essentials with 8 to 16 circuits. Choose a whole house transfer switch if you want every circuit in your home protected without exception, you are installing a 22kW or larger generator, you have central air conditioning and want it operational during outages, or you prefer the simplest and most comprehensive backup power setup.
IB Lighting carries both load center transfer switches and whole house transfer switches from Generac, Kohler, and Cummins. Call (800) 674-9019 to discuss which configuration is the best fit for your home and generator, or browse our transfer switch selection online.