
Load Bank Testing for Industrial & Commercial Generators
50+ years · Local Colorado Springs expers · All makes & models · In-stock parts · EGSA Certified Pros
Generator Source performs professional load bank tests to verify that your standby or prime power system can deliver rated power safely and reliably when it matters most.
What Is a Load Bank Test?
A load bank safely applies a controlled, incremental electrical load to your generator and measures performance at each step. Our technicians simulate real-world conditions, typically at 25%, 50%, 75%, and 80%, to verify the unit’s capability, stability, and cooling capacity over time.
Why Load Bank Testing Matters
A generator that starts is not the same as a generator that performs.
- Power Rating: Confirms the unit can produce rated kW and maintain voltage and frequency stability under real demand.
- Wet Stacking: Prevents wet stacking in diesel units by burning off unburned fuel and carbon.
- Hidden Issues: Reveals hidden issues (cooling, fueling, controls) before an outage.
- Compliance: Documents performance for audits, insurers, and compliance programs.
What We Test & Verify
- Electrical performance: voltage, frequency (Hz), phase balance, power factor
- Output stability: response to step-load changes, transient recovery
- Thermal behavior: exhaust temps by cylinder (IR checks), coolant temps, oil temps
- Mechanical health: vibrations, abnormal noise, leaks, belt condition
- Controls & protection: alarms, shutdowns, governor/AVR response, safeties
- Emissions health (diesel): soot and visible smoke reduction after full-load operation
- Deliverables: a signed Load Bank Report with all readings, observations, pass/fail notes, and recommendations.
Our Load Bank Testing Process
- Pre-test inspection: Visual checks, fluid levels, belts/hoses, battery and starter condition, fuel supply, and airflow.
- Warm-up & baseline: Verify no-load voltage/frequency, governor and AVR baseline.
- Step loading: Apply 25% → 50% → 75% → 80% load; hold each stage to stabilize and log readings.
- Sustained full-load run: Prove continuous power delivery; monitor cooling/exhaust temps and engine response.
- Step unload & recovery: Observe voltage/frequency recovery and protective device behavior.
- Post-test inspection: Re-check leaks, connections, codes/alarms; review results with your team.
- Report & recommendations: Detailed documentation plus prioritized action items (e.g., cooling service, fuel polishing,
Common Issues a Load Bank Test Catches Early
Underfrequency/Undervoltage
Underfrequency/undervoltage under load (governor/AVR tuning needed)
Fuel Starvation
Fuel starvation from clogged filters or contaminated fuel
Wet Stacking
Wet stacking from chronic low-load operation
Load Bank Pass/Fail Criteria
- Maintain rated kW at specified voltage and frequency with acceptable droop limits
- Hold phase balance within tolerance
- Sustain full-load temps without alarms or shutdowns
- Recover smoothly from step-load changes
- Failures trigger a corrective action plan, our technicians outline exactly what to fix and how urgent it is
Load Bank Videos
350kW Caterpillar Natural Gas Generator LOAD BANK TEST | 3-Phase, 277/480V Unit 093209
350kW Caterpillar Natural Gas Generator LOAD BANK TEST | 3-Phase, 277/480V Unit 093208
Power in Action ⚡ Generac 200 kW Load Bank Test! #dieselgenerators #generatorsales #generac
250kW Cummins Diesel Generator LOAD BANK TEST | 3-Phase, 120/208V (Unit 091466)
60kW Natural Gas Generator | Load Bank Test | Unit 093123
1250kW Caterpillar Diesel Generator LOAD BANK TEST | 3-Phase, 277/480V Unit 093010
2250kW Kohler Rehlko Diesel Generator LOAD BANK TEST | 3-Phase, 480V Unit 91801
80kW Kohler Rehlko Diesel Generator LOAD BANK TEST | 3-Phase, 240V Unit 093241
2250kW Kohler Rehlko Diesel Generator LOAD BANK TEST | 3-Phase Mobile Power Unit 91800
800kW Cummins Diesel Generator LOAD BANK TEST | 3-Phase, 277/480V Unit 090350
Brand New 600kW Caterpillar Diesel Generator Load Bank Tested and For Sale
600kW Kohler Rehlko Diesel Generator LOAD BANK TEST | 3-Phase, 480V Unit 092298
Load bank testing this Baldor 140 kW | Unit 092014
200kW Kohler Rehlko Diesel Generator LOAD BANK TEST | 3-Phase, 480V Unit 90279
250kW Cummins Diesel Generator LOAD BANK TEST | 3-Phase, 277/480V Unit 092761
60kW Natural Gas Generator | Load Bank Test | Unit 093123
092639 Load Bank Test
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Still have questions?
Generator Source specializes in low-hour, used, new, and surplus generator sets. We have a wide variety of generator sizes and models to fit any project. We are not a broker, we own what we sell.
Call us today (877-866-6895) or click Contact Us to be connected with one of our experienced sales reps.
We have 350+ generators in stock and ready to ship!




