Surge protection disconnects. Nothing reconnects you.
Late-afternoon brownouts
When every site runs air conditioning, pedestal voltage drops below 104 V RMS. Compressor motors draw more current and run hot long before anything trips.
Your EMS cuts shore power
A surge protector or inverter-charger disconnects at its low-voltage limit. It protects the coach, but leaves it without power until someone starts the generator.
Nobody home to react
A full outage, or one dead leg on a 50 A service, while you are away and the pets are inside.
Monitor, decide, start, restore.
Both legs, continuously
Each leg is measured on its own, so a sag, a full outage and a single dead leg are told apart.
Your trip point, your delay
Set the sag threshold and how long it must last. Short flickers at the pedestal are ignored.
Cranks, verifies, retries
Fires the generator, confirms it is running, and retries with rest periods. After three failed attempts it locks out and reports it.
Back to shore power
Once the pedestal holds steady for five minutes, the generator runs its cool-down and stops.
An engine that starts on its own needs hard limits.
Fail-safe by design: the safety functions are wired in hardware, so they hold even if the software doesn’t.
- CO detector lockoutConnects to a CO alarm with a relay output. An alarm blocks any start and shuts a running generator down.
- Key switch for serviceTurn the key to OFF and take it with you. The box can’t start the generator while you work on the rig, even with shore power unplugged.
- Your wall switch still worksPlugs in between the generator and its original harness. Nothing is cut, and unplugging the box restores the factory wiring.
- No runaway crankingA limited number of attempts, and the generator’s own overcrank protection stays in charge.
Simple, or on your phone.
Set it and forget it
- Automatic start and stop on outage and brownout
- Settings on switches inside the box
- Status lights on the front
- No app, no Wi-Fi needed
Know what happened, wherever you are
- Everything in Basic
- Phone alerts: power lost, generator started, start failed, power back
- Live voltage of both legs and a start log
- No monthly subscription planned
First target: Onan QG series (Marquis Gold 5500) with the standard sealed remote connector. Other generators are planned; tell us yours below. Specifications are design targets and may change.
Generator auto start on shore power loss: FAQ
Will my RV generator start automatically if the campground loses power?
Usually not. Most factory auto generator start (AGS) systems start on low battery, temperature or A/C demand, not on shore power loss, and a transfer switch only moves the load once the generator is already running. VoltSentry watches the pedestal itself and starts the generator on a full outage, a dead leg or a sustained brownout.
Can I leave my dog or cat in the RV with the A/C on?
That is the main reason VoltSentry exists. If shore power drops while you are away, it starts the generator so your coach's transfer switch can power the A/C again. The Connected version sends a phone alert when power is lost, the generator starts, a start fails and power comes back, so you know when to head back. It does not replace checking on your pets.
What counts as a brownout, and why does it matter?
On hot afternoons campground pedestals can sag below 104 V when every site runs air conditioning. Low voltage makes A/C compressors draw more current and run hot, and many surge protectors and EMS units then cut shore power entirely. You set the trip point between 102 and 108 V and how long the sag must last, so short flickers are ignored.
Does it work with my transfer switch?
Yes, if your RV has an automatic transfer switch, as most Class A motorhomes with a built-in generator do. VoltSentry only starts and stops the generator; your existing switch moves the load. RVs where you plug the shore cord into a generator outlet by hand would need an automatic transfer switch added.
Which generators will it support?
The first target is the gas Onan QG series (Marquis Gold 5500, QG 4000 and similar) with the standard remote-start connector. It plugs in between the generator and its original harness, so your wall switch keeps working. Tell us your generator model in the sign-up form; that decides what we support next.
I already have a factory auto-start. Do I still need this?
Factory systems start on battery or temperature, so after an outage the generator only starts once the coach is hot or the batteries are low. VoltSentry is being designed to work alongside them and add the missing shore-power trigger and remote alerts.
What if the generator runs out of fuel?
On most gas motorhomes the generator shares the chassis fuel tank and stops at about a quarter tank, which still gives many hours of run time. If the generator stops while shore power is still out, or three start attempts fail, VoltSentry locks out and reports it instead of cranking again.
Is it safe to have a generator start on its own?
The safety functions are wired in hardware: a CO detector alarm blocks any start and stops a running generator, a removable key switch locks it out while you work on the rig, and cranking is limited. Always keep a working CO detector in your RV.
How much will it cost, and is there a subscription?
VoltSentry is in development and not for sale yet, and the price is not set. No monthly subscription is planned for either version. Join the early list to hear when beta units are ready, and tell us what you would expect to pay.
Help us build the right one.
We’re building prototypes now. Join the list to hear when beta units are ready. Your answers decide which models we support first and what the final product looks like.
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