Understanding components of load banks
Load banks are assembled with various quantities of components . for example , Load element- resistors , PLC ,AC/DC contactors, fuses, circuit breakers, temperatures sensors, relays, switchingmode power supply ,voltage/current transformers ,limit switches, terminal connectors, LEDs, push buttons/toggles, cables, busbars etc.
Understanding circuit of load banks
Overview of Load Bank Operation
A load bank receives electricity from a power source, converts it to heat, then ejects this heat from the unit. By consuming power in this way, it places a corresponding load on the power source. To do so, load banks absorb a massive amount of current. A 1000 kW, 480V load bank will continuously absorb more than 1200 amps per phase and will produce 3.4 million British Thermal Units of heat per hour. Load banks are typically used to
1)stress a power source for testing purposes, such as periodic testing of a generator;
2)affect the operation of the prime mover, such as providing minimum load to prevent the buildup of unburned exhaust residues in the diesel engines of gensets;
and/or (3) adjust the power factor of an electrical circuit. Load banks apply load by directing current through load elements that use resistance or other electrical effects to consume power.
Regardless of purpose of operation, any developed heat must be removed from the load bank to avoid overheating. Heat removal is typically accomplished using an electrically powered blower, which ejects hot exhaust out of the load bank.
Essential Load Bank Circuits
Separate circuits are used to operate the load elements, the blower system, and the devices that control them. Figure 1 provides a simplified one-line diagram of the relationship of these circuits. Each is further described in the following sections.
