Technical Guide · Generators & Power Quality
Dirty Power from GeneratorsProtect your WerkMaster floor grinder
Portable and tow-behind generators are essential on job sites without access to utility power. However, an undersized generator or unstable power supply can cause VFD faults, equipment downtime, and costly repairs.
Understanding dirty power and choosing the right generator can help protect your WerkMaster grinder and keep your crew productive.
What Is Dirty Power?
Dirty power is electricity characterized by unstable voltage, fluctuating frequency, voltage spikes, or excessive Total Harmonic Distortion (THD).
WerkMaster grinders use Variable Frequency Drives (VFDs) to control motor speed and torque. Unlike basic power tools, these electronic systems are sensitive to poor power quality.
| Feature | Clean Power | Dirty Power |
|---|---|---|
| Waveform | Smooth, consistent sine wave | Distorted or irregular |
| THD | Typically below 3–5% | May reach 10–30% or higher |
| Voltage | Stable within specifications | Fluctuates under load |
| Impact | Reliable operation | Faults, overheating, or premature failure |
How Dirty Power Affects Your Grinder
Voltage Spikes
Sudden load changes, such as a dust collector cycling, can trigger VFD overvoltage (OV) faults and stop the machine.
Voltage Drops
When a generator struggles to maintain voltage under load, the VFD may draw more input current to maintain output power, increasing heat and stressing electronic components.
Harmonic Distortion
High THD can increase electrical losses, cause nuisance trips, and contribute to overheating in drive components and motor windings.
Common Causes
Undersized Generators
Insufficient capacity leaves little reserve for changing loads and startup demands.
Poor Regulation
Generators that cannot maintain stable voltage and frequency as loads change may cause equipment faults.
Unbalanced Phase Loads
Running 120V accessories from one leg of a three-phase generator can create phase imbalance.
Long or Undersized Extension Cords
Excessive cable length or insufficient wire gauge causes voltage drops. Heavier-gauge cable may be necessary, depending on the distance and load.
How to Protect Your Equipment
Follow these four steps to reduce power-related faults, prevent downtime, and protect your WerkMaster grinder.
Choose the Right Generator
A generator rated at 2–2.5 times the continuous power draw may provide useful reserve capacity, but requirements vary. Confirm sizing with WerkMaster and your generator supplier.
Verify Power Quality
Choose a commercial-grade generator with effective Automatic Voltage Regulation (AVR) and good frequency control. Where required by your equipment, look for THD below 5% and confirm compatibility with your grinder’s voltage, phase, and frequency requirements.
Consider Additional Protection
A line reactor or isolation transformer may help address certain electrical disturbances, but neither corrects every power-quality problem. Consult a qualified electrician or equipment supplier before installation.
Follow Proper Startup and Shutdown Procedures
- Allow the generator’s voltage and frequency to stabilize before powering on your grinder.
- Turn off and disconnect the grinder according to the manufacturer’s instructions before shutting down the generator.
Keep Your Crew Grinding
Proper generator sizing, stable power, suitable cabling, and correct operating procedures can help reduce faults, prevent downtime, and protect your investment.