When the power goes out, a standby generator restarts the house automatically — but whether it should also carry a 48 A wall charger is a sizing decision, not a default. The EV-ACT5006T draws up to 11.5 kW as one continuous load, which can exceed a smaller standby unit’s continuous rating before the fridge, lights and heating are counted. Most owners keep the charger off the backed-up circuits, or shed it automatically.
Key Takeaways
- A 48 A charger draws up to 11.5 kW continuously — enough to exceed a smaller standby unit’s rating alone.
- The decision is made at the transfer switch: backed-up circuit, load shedding, or a bigger generator.
- Judge generators by their continuous rating, and do the comparison on paper first.
- Never improvise connections to a panel; transfer equipment is licensed work.
A Standby System Is a Different Setup from a Portable Generator
Portable-generator advice assumes a small unit, a charger turned down low, and someone watching. A standby installation is the opposite: the generator is fixed, an automatic transfer switch moves chosen circuits onto it when the grid fails, and it all happens whether anyone is home or not. The question is decided in advance, at the panel: if the charger’s 60 A circuit sits on the backed-up side, the generator will be asked for the car’s charge whenever the car asks — including mid-outage, in the middle of the night. Our guide to whether home EV chargers are safe covers the supervision logic behind that.
The Arithmetic: One Load Can Eat the Whole Rating
Generators are judged by their continuous (running) rating, not the peak figure. The comparison that matters is that rating against everything the transfer switch feeds at once — and the charger’s share is up to 11.5 kW, drawn steadily for hours.
| Question | How to answer it |
|---|---|
| What is the standby unit’s continuous rating? | Read the rating plate or the manual — not the headline peak number |
| What does the charger alone take? | Up to 11.5 kW at the full 48 A setting |
| Worked example (labelled) | A unit rated 10 kW continuous cannot carry an 11.5 kW charger at all — the charger alone exceeds it, before any house load |
| What else is on the backed-up panel? | Every backed-up circuit competes for the same rating — list them with your installer |
If the numbers do not close, the answer is not to try it and see: an overloaded generator trips its own protection or sags under the load, and repeated restarts are hard on everything connected — the objection our guide to why a charger trips the breaker describes from the circuit side.
Three Ways Owners Usually Set It Up
- Charger excluded from backup. The simplest arrangement: the transfer switch feeds the house essentials, the charger waits, and charging resumes when the grid returns.
- Load shedding fitted. Load-management modules exist that drop a large load, such as the charger, when the generator is heavily loaded and restore it when there is headroom. Fitting one is the generator installer’s work.
- Generator sized for the car from the start. If charging during outages is a genuine requirement, the standby unit and transfer setup are sized for house plus charger together, on paper, before purchase.
What not to do is improvise: no manual cable arrangements, no feeding the panel except through the installed transfer equipment, no defeating either unit’s protections. Transfer equipment is licensed work. When the grid returns, the usual post-outage checks apply, and the moment of restoration is what our guide to surge protection for EV chargers is about.
Where the EV-ACT5006T Fits
The EV-ACT5006T is a fixed Level 2 wall charger: hard-wired or on a NEMA 14-50 plug, up to 48 A. Its strength is being always ready on grid power; it is not the flexible tool for backup situations. Owners who want an outage option usually keep a small adjustable portable, such as the EV-ACS3210T, whose 10–32 A steps can be turned down to what a backup supply can hold. Agree with your electrician and generator installer which side of the transfer switch the 60 A circuit belongs on, and write it down for whoever services the system later.
Frequently Asked Questions
Will running the charger damage the standby generator?
Overloading is the risk, and it is a sizing question, not a charger fault. A generator asked for more than its continuous rating trips its protection or struggles; do the sizing on paper first.
Can I try the charger on backup power once and see?
That is the experiment the arithmetic replaces: compare the continuous rating with the charger’s 11.5 kW plus the other backed-up loads first.
Does charging restart by itself when the transfer switch flips back to grid power?
It depends on the charger and the car; some resume, others wait for a fresh start. After any outage, check the charger status rather than assuming the car charged.
Related Reading
- Are Home EV Chargers Safe?
- Should EV Chargers Have Surge Protection?
- Why Does My EV Charger Keep Tripping the Breaker?
