Stress banks exist in a variety of shapes and sizes, depending on how much load they impart to the power sources they assess. There are two types of load banks: resistive and reactive. Each of them has advantages in certain situations. To locate the best options for doing testing on your power sources, learn the distinctions between ac resistive load banks and reactive load banks.
Load Banks: Resistive vs. Reactive
You may need resistive, reactive, or both types of load banks depending on your generators and how you use them. The generators are subjected to a variety of loads as a result of these devices. The most prevalent forms are resistive, while reactive power loads include inductive and capacitive power loads.
Uses of a Resistive Load Bank
In the same way that lights or appliances take power from a generator, ac load bank does. These testing equipment work well with generators that convert electricity into heat or light for common power purposes. Tools that transform electrical energy into heat include light bulbs, lamps, and space heaters.
These load banks apply a defined real power demand, measured in kW, to the generator to keep the power supply’s cooling system, exhaust, and engine running. A reactive load bank evaluates the generator for full apparent power in kVA, although they don’t.
Uses of a Reactive Load Bank
Inductive loads are commonly employed in construction and backup power supply, and reactive load banks can emulate them. Capacitive loads produce a leading power factor, while inductive loads produce a lagging power factor. The inductive kind is more common in objects that use magnetism to convert power into motor operation.
Reactive load bank testing is the most effective for institutions that rely on emergency generators to run equipment for business-critical operations or life support, such as data centers and hospitals.
What Is the Function of Resistive Banks?
All of the applied electrical energy is converted into heat via resistor load banks. For cooling, larger kW load banks usually include an integrated blower. Some load bank designs, such as Duct Mounted, rely on cooling airflow from other sources, such as an engine radiator, rather than having their cooling system.
Up to 3,000 kW, self-contained ac resistive load banks are popular. Choose a load bank with a capacity equal to or greater than the power source at the rated output voltage for full kW load testing.
What Is the Function of Reactive Load Banks?
Reactive load banks simulate the power source’s full apparent load in kVA. Reactive models, however less prevalent than resistive load banks, are part of the NFPA 110 testing requirements for nonunity power factor equipment field or factory acceptance testing.
Unlike resistive loads, which have a power factor of 1.0 and a load of 100%, reactive loads have a power factor of 0.8 and a load of 75%. Because of the difference in power factors and loads, voltage dips from the generator are 25% higher than voltage drops from resistive loads. Reactive load banks are used to test for systems that are sensitive to voltage drops in this way.