EA-EL 9750-20 B 3U Electronic Load

This series of compact electronic DC loads, called EA-EL 9000 B, succeeds the former series EA-EL 9000 A and offers useful voltage, current and power ratings for a multitude of applications. All models support the four com-mon regulation modes constant voltage (CV), constant current (CC), constant power (CP) and constant resistance (CR). 

An FPGA based digital control circuit provides interesting features, such as a function generator for arbitrary curves and a table based XY function for the simulation of nonlinear internal resistances. 

The ratio between power consumption and height of the devices has been significantly increased compared to the former series EA-EL 9000 A. The models with 3U of height are capable of consuming DC power of up to 7.2 kW per unit.

The front offers a large color TFT touch panel for an intuitive kind of manual operation, such as it's prolific nowa-days with smart phones or tablet computers. In parallel operation of multiple devices, a master-slave bus is used to link multiple units to a bigger system where the actual values are totaled.

Features:

• Wide AC supply voltage range: 90...264 V
• Input power ratings: 1.2 kW up to 7.2 kW, expandable in cabinets up to 72 kW
• Input voltages: 80 V up to 750 V
• Input currents: up to 510 A per unit
• FPGA based digital control circuit
• Multilingual color touch panel
• Extensive function generator
• Adjustable protections: OVP, OCP, OPP
• Operation modes: CV, CC, CP, CR
• Galvanically isolated interfaces (analog and USB)
• Master-slave bus for parallel connection
• Slot for a wide selection of industrial interface modules
• SCPI and ModBus RTU/TCP command set
• LabView VIs and remote control software (Windows)

Power ratings, voltages, currents

The available voltage range portfolio goes from models with 0...80 V DC up to models with 0...750 V DC. Input cur-rents up to 0...510 A with only one unit are available. The series offers various power classes amongst the single models which can be extended up to 72 kW in cabinets for a significantly higher total current.

Construction

All models are built in 19“ wide rack enclosures with 3U of height and 460 mm (18.1”) of depth, which makes them ideal for use in 19“ cabinets of various sizes, for example 42U, and for the design of systems with very high power. It's furthermore possible to build cabinet systems with mixed equipment, i.e. electronic loads and power supplies, in order to achieve the source-sink principle with high power ratings.

Handling (HMI)

Manual operation is done with a TFT touch panel, two rotary knobs and a pushbutton. The large color display shows all relevant set values and actual values at a glance. The whole setup is also done with the human-machine interface, as well the configuration of functions (square, triangle, sine) etc. The display is multilingual (German, English, Russian, Chinese).

Share bus, parallel connection and two-quadrants operation

The so-called „Share Bus“ is an analog connection at the rear of the devices and is used to balance current across multiple similar units in parallel connection, such as with loads of this series and series EA-ELR 9000. It can also be used to build a two-quadrants system in connection with power supplies of series EA-PSI 9000 or EA-PS 9000. This system is dedicated for testing purposes using the source-sink principle.

Thermal derating

The devices of the EA-EL 9000 B series are equipped with thermal derating in order to avoid overheating when op-erating in the maximum power range. The lower the ambient temperature and the better the cooling, the higher the power that the load can take. The nominal intake power before the derating starts is defined at 21°C ambient temperature.

Battery test & MPP tracking

For purposes of testing all kinds of batteries, such as for example constant current or constant resistance dis-charging, the devices offer a battery test mode. This show extra values for elapsed testing time and consumed capacity (Ah). All the data can be recorded directly to USB stick.
For photovoltaics related tests there is another function included as standard: MPP tracking. Four modes allow for simulation of the typical characteristics of solar inverters being connected to solar modules or panels. The function is used to determine typical operation parameters, such as the so-called Maximum Power Point and the related values UMPP, IMPP and PMPP. One of the modes even offers particular analysis with different irradiation values in form of a table with 100 points.

Control software

Included with the devices is a control software for Windows PC, which allows for the remote control of multiple identical or even different types of devices. It has a clear interface for all set and actual values, a direct input mode for SCPI and Mod-Bus RTU commands, a firmware update feature and the semi-automatic table control named Sequencing.
Optionally unlockable with a license code, the app Multi Control can monitor and control up to 20 units at once and in one windows. The sequencing feature and data logging are here available as well. 

Datasheet:

EA Series EL 9000B 3U-6U 1.2kW up to 7.2kW Datasheet