Your Generac generator often continues to run for a short period after utility power is restored as a normal part of its operational cycle, designed to ensure the stability and continuity of your home's electricity supply.
Normal Operational Delay
Most emergency generators, including Generac models, are engineered to continue running for a few minutes after the utility company's power has been restored. This is a deliberate design feature to confirm that the flow of electricity from the utility company is continuous and stable before switching your home's power source back.
This brief post-restoration operation serves several critical purposes:
- Power Stabilization Check: The generator's control panel continually monitors the incoming utility power for a predetermined period to ensure it's truly stable and reliable. This prevents your home from experiencing frustrating power fluctuations or "brownouts" immediately after the main power returns, which could potentially harm sensitive electronics.
- Avoiding Rapid Cycling: This brief delay prevents the generator from rapidly starting and stopping if utility power momentarily flickers on and off. Such "chattering" or rapid cycling could cause excessive wear and tear on the generator, its transfer switch, and even damage connected appliances.
- Engine Cool-Down: Like any internal combustion engine, your generator's engine needs a cool-down period. This post-restoration run allows the engine to gradually cool down before shutting off, which is vital for its longevity and performance, preventing heat-related stress on components.
- Transfer Switch Protocol: The automatic transfer switch (ATS) has a built-in delay. Once it senses stable utility power, it waits for this programmed period (typically 5-15 minutes, but can vary by model and configuration) before commanding the generator to shut down and transferring the electrical load back to utility power.
Typical Post-Restoration Cycle
Understanding the typical shutdown sequence can help alleviate any concerns:
- Utility Power Returns: The ATS detects the return of stable utility power from the grid.
- Generator Runs On-Load (Briefly): The generator continues to power your home while the ATS confirms utility power stability.
- Transfer to Utility Power: After a set delay (e.g., 5-15 minutes), the ATS switches your home's electrical load back to utility power.
- Generator Cool-Down (No Load): The generator continues to run for a few more minutes (unloaded, meaning it's no longer supplying power to your home) to allow its engine to cool down properly.
- Generator Shuts Down: The generator finally shuts off, returns to standby mode, and waits for the next power outage.
The total time your Generac generator might run after power restoration can vary but generally falls within the ranges shown below:
| Cycle Stage | Typical Duration (Approx.) | Purpose |
|---|---|---|
| Utility Power Stabilization Check | 5-15 minutes | Ensure stable, continuous incoming utility power |
| Generator Cool-Down (Unloaded) | 1-5 minutes | Protect engine longevity and prevent overheating |
| Total Post-Restoration Run | 5-20 minutes | Overall process for reliable transfer and healthy shutdown |
When to Be Concerned
While a short post-restoration run is normal, excessive running or unusual behavior indicates an issue that might require attention. You should be concerned if your Generac generator:
- Runs for more than 20-30 minutes after utility power has been visibly stable and restored to your home.
- Displays an error code on its control panel.
- Fails to switch back to utility power, meaning your home is still running solely on generator power even after the normal run time has elapsed.
- Produces unusual noises, vibrations, or smells during its post-restoration operation.
If any of these situations occur, it's advisable to consult your Generac owner's manual for troubleshooting steps or contact a certified Generac technician for inspection and service.
