Best RV Automatic Transfer Switches for Shore Power and a Generator

Plugging a generator into an RV that is also connected to shore power, without a transfer switch between them, can push generator voltage backward through the shore power cord toward the pedestal. That is a real hazard to anyone working on that circuit at the park, and it can also damage the generator or the RV's own wiring if the two sources are not synchronized. A transfer switch removes the possibility entirely by physically allowing only one source to reach the panel at a time, switching automatically as soon as it detects the active source has changed.

Every unit here is rated at 50A, so voltage rating and any added transfer delay are the details worth checking against the specific coach and generator combination.

A manual transfer switch requires someone to physically move a lever or breaker to select shore power or generator power, with a break-before-make design that avoids ever connecting both at once, but only if the person operating it does not skip a step. An automatic transfer switch senses which source is live and switches on its own, with no operator action required and no window for human error. For an RV that gets plugged into unfamiliar pedestals and occasionally run on a generator by someone in a hurry, automatic operation is the safer default.

Every switch in this roundup is rated at 50A, which matches a true 50A service using two separate 120V legs. A rig on a 30A service uses a different, lower-amperage transfer switch built for a single 120V leg, and the two are not interchangeable. Check the RV's actual shore power plug and the rating printed on its power center before buying a replacement switch, since a 50A switch installed on a 30A service, or the reverse, will not match the wiring it is meant to protect.

A transfer switch installs between the RV's main AC panel and the two possible incoming power sources, typically wired in ahead of the breaker panel so that whichever source is selected feeds the entire panel through the switch. On rigs with an onboard generator, this is often already done at the factory, with the transfer switch built into or mounted right next to the power center. Adding a portable generator to a rig that never had one usually means adding the transfer switch as a new component during that same upgrade, since a portable generator was never accounted for in the original wiring.

A rig running both a generator and an inverter/charger needs to think through how the two interact, since an inverter/charger's own built-in transfer switch handles shore power versus inverter power, but a separate transfer switch is still required to add a generator into the mix safely. In that configuration, the standalone transfer switch typically feeds its output into the inverter/charger's shore power input, so the inverter/charger sees either the shore power pedestal or the generator, never both, while its own internal switch continues handling the changeover to inverter power when neither AC source is present.

A transfer switch that fails to move to generator power when the generator is running, or fails to return to shore power once it is available again, is usually either a wiring fault at the switch's control connections or a genuinely failed internal relay rather than a problem with the generator or the pedestal itself. Checking that the generator is actually producing correct voltage at its outlet, using a simple multimeter, rules out the generator as the cause before assuming the switch itself has failed. Replacing a transfer switch is usually more straightforward than diagnosing an intermittent fault inside one, which is part of why the OEM replacement parts in this roundup, sized and wired the same as the failed original, are a common repair path.

A transfer switch that fails within its warranty period is usually replaced directly by the manufacturer once a fault is confirmed, though the diagnostic step of ruling out the generator and the wiring first, described above, is often required before a warranty claim is accepted. Outside the warranty window, replacing a transfer switch is a modest expense relative to the rest of an RV's electrical system, and choosing a like-for-like OEM part, such as the WFCO T57 for a coach already built around WFCO components, tends to minimize the labor involved compared with adapting a different brand's switch to the existing wiring.

A rig with no generator at all, running purely on solar and shore power, does not strictly need a transfer switch in the traditional sense, since there is only one AC input source to manage. The moment a generator is added to that same rig, even a small portable unit kept as backup for cloudy stretches, a transfer switch becomes necessary again, since shore power and the generator both become live AC sources that could otherwise be connected simultaneously. Anyone planning a lithium conversion that includes adding a generator for the first time should budget for a transfer switch alongside the battery and charging components, not treat it as an afterthought once the rest of the system is wired.

These picks were researched from published manufacturer specification sheets covering amp rating, voltage rating, and transfer behavior, then cross-checked against verified owner reviews for reported switching reliability and fit against OEM power centers. None of these switches were tested in person for this page.

Compare these on voltage rating and transfer delay first, since all four share the same 50A current rating.