This instability can negatively affect concrete grinders, vacuums, and other equipment commonly used in the concrete surface preparation industry. Disabling idle control, using appropriate protective devices, or selecting an industrial generator without the idle speed control—such as the DiamaPro DP-GEN-22Kw or DP-GEN-15Kw—are effective ways to reduce risk and ensure reliable operation.
How the Idle Control Unit Affects Sensitive Electronics on a Generator
Most portable generators are equipped with an idle control unit (sometimes called Eco-Throttle, Smart Throttle, or Economy Mode). This system automatically reduces engine speed when the generator is under little or no load, then increases speed when a load is applied.
While this feature saves fuel and reduces noise, it can have unintended effects on sensitive electronics.
What the Idle Control Unit Does
- Lowers engine RPM when no or light load is present
- Increases RPM when electrical demand increases
- Responds mechanically and electronically to load changes
On traditional (non-inverter) generators, engine speed is directly tied to:
- Output voltage
- Output frequency (Hz)
Why This Matters for Electronics
Sensitive electronics—such as speed controllers or VFDs, computers, motherboards, and control boards—require stable voltage and frequency to operate properly. These components are commonly used in concrete grinders, vacuums, and other concrete surface preparation equipment and can be adversely affected by voltage or frequency fluctuations.
When idle control is enabled:
- Voltage and frequency may fluctuate during load changes
- There can be a delay as the engine speeds up to meet demand
- Brief undervoltage or frequency dips may occur when a device turns on
These short disturbances may not affect basic tools or lights, but sensitive electronics can:
- Reset or shut down unexpectedly
- Experience data loss or corruption
- Suffer long-term damage to power supplies or internal components
Best Practices for Protecting Sensitive Electronics
- Disable idle control when powering sensitive equipment (if possible)
- Allow the generator to reach full operating speed before plugging devices in
- For frequent electronics use, consider a generator without an idle control unit - such as the DiamaPro DP-GEN-22Kw or DP-GEN-15Kw.
Are There Still Limitations to Generators without an Idle Control Unit?
Yes—especially on jobsites with high-demand tools.
High Inrush Loads (Concrete Grinders, Vacuums, Saws)
All generators can struggle if:
- The generator is undersized for the equipment
- A tool has very high startup current
- Multiple high-load tools start at the same time
Possible symptoms:
- Brief output limiting
- Soft shutdowns or overload warnings
- Tool startup hesitation
These are usually capacity issues, not idle control problems.
Best Practices When Using Generators on Jobsites
- Size the generator well above the grinder’s running and startup load
- Start high-draw tools one at a time
- Avoid long, undersized extension cords
- Leave eco mode ON for light loads; turn it OFF if repeated overloads occur