Load Banks: A Test of Power

Using Load Banks Can Help Prevent a Loss of Power and Production Delays

Portable and trailer-mounted load banks are the perfect solution to ensure your generator maintains proper pressure levels and temperature while also producing the optimal horsepower for your operations or facility.

A load bank is the most efficient, effective, and accurate way to test a generator’s ability to handle the day-to-day demands of a facility and identify any issues before a generator is needed in an emergency.

Load banks serve as testing devices designed to predict and measure how a power source will perform by simulating energy draw when testing generators, turbines, or uninterrupted power supplies. Electrical contractors often use load banks to ensure generators are dependable and capable of their highest load capacity. When a load bank is deployed, an artificial load is placed on the generator to increase its kW slowly. When the kW load rises, the load bank goes to work, measuring and recording engine capabilities over time, ultimately testing the generator’s ability to function at its heaviest load.

By using a load bank to help identify deficiencies in primary and secondary power sources before they fail, electrical contractors can prevent a loss of power resulting in production delays, rising costs, and the loss of human life during an emergency or disaster.

While there are four types of load banks, resistive load banks are the most common. These load banks draw a designated power load in kW from the generator to check and ensure the safe operation of the cooling and heating system, exhaust and engine. They will mimic the load the generator or equipment produces in standard operation.

Other types of load banks include reactive, inductive and capacitive.

Deploying load banks to test generators at their full kW rating ensures the generator can produce the highest output. Load bank testing should be considered a part of your annual maintenance routine to safeguard against performance issues and ensure overall functionality.

When load banks are used to test generators annually, facility and operation managers can prevent underloading. When generators are run on lighter loads, unburnt fuel and soot can build up in the generator’s exhaust system and become a fire hazard or even cause the generator to fail. Testing at full capacity and temperature burns the unused fuel and removes the risk of a breakdown or safety hazard.

With individual load banks rated from 125 kW to 3,000 kW, Herc Rentals offers a wide range of load bank solutions sure to meet the demands of any application, whether it’s testing standby emergency power such as generators, uninterruptible power supplies, turbines, battery systems and regenerative power absorption of large generators, and other load applications.

Features and benefits include:

  • Portable or trailer-mounted for easy transport to job site
  • Portables built to fit through any industrial door
  • Intelligent operator control options
  • Networking capability for up to 32 load banks connected via RS-485 cable
  • Quick-Connect, color-coded Cam-Lok power connectors
  • Control Power Emergency-Stop (E-STOP) push button is provided to disable control power voltage to all operator control power circuits
  • Backlit LCD offers superior viewing for both bright and dim light conditions

Load banks:

  • 125 kW – dual voltage – ideal for testing 208VAC, 240VAC or 480VAC
  • 600 kW – dual voltage – ideal for testing 208VAC, 240VAC or 480VAC
  • 1,000 kW – the most compact 1,000kW (480VAC) portable in the industry
  • 3,000 kW – trailer-based, for testing larger power systems


  • Oil and gas industries
  • Data centers
  • Hospitals and nursing homes
  • Industrial and manufacturing facilities
  • Any facility with a backup generator

Whether choosing a lightweight, portable load bank for indoor use or a trailer-mounted load bank for outdoor applications, Herc Rentals’ selection of load banks are ideal for regularly scheduled maintenance testing and commissioning mission-critical standby emergency power systems. Contact your local Herc Rentals representative for your facility for more information on what load bank is the right one for your facility.

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