Ea Elektro Automatik EA Elektro-Automatik EA-ELR 9750-44 3U Electronic Load 0 - 44 A 0 - 750 Vdc 0 - 7000 W 33200408 Ficha De Dados

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EA Elektro-Automatik GmbH

Helmholtzstr. 31-33 • 41747 Viersen

Germany

Fon: +49 2162 / 3785-0

Fax: +49 2162 / 16230

Configuration C:
Multiple e-loads and multiple power supplies for increased total 

performance, plus 1 test object (E.U.T). 
The combination of load units and power supply units each 

create a block, a system with certain power. Here it is also 

necessary to match the nominal values of the two systems, 

like the 80 V DC input of the loads to a max. 80 V DC output 

of the power supplies. The max. number of 10 units cannot 

be exceeded. Regarding the Share bus connection, all e-load 

units have to be slaves, while one of the PSUs has to be set 

as master. In case the digital master-slave bus is also wired, 

one load unit will be defined as master for the MS system of 

e-loads, but still has to be slave on the Share bus, which is 

activated with parameter “PSI/ELR system” in the setup menu.

3.10.3.3  Settings on the devices
Regarding the general 2QO operation where the Share bus connection is sufficient, no extra setup is required on 

the load unit(s). On any of the power supplies, but preferably PSU 1, you need activate master-slave mode and 

set it to MASTER, unless it is already the master unit of a master-slave system over digital MS bus. Refer to the 

documentation of the power supply for further information. Also see 3.4.3.1.
For safety of the connected E.U.T / D.U.T and to prevent damage, we recommend to adjust supervision thresholds 

like OVP, OCP or OPP on all units to the desired levels, which will then switch off the DC output resp. the DC input 

in case of excess.

 

3.10.3.4  Application example
Charging and discharging a battery with 24 V/400 Ah, using the wiring example in configuration A.
•

Power supply PSI 9080-170 3U with: I

Set

 = 50 A, P

Set

 = 5000 W 

•

Electronic load ELR 9080-170 set to: I

Set

 = max. discharge current of the battery (eg. 100 A), P

Set

 = 3500 W, U

Set

 

= 24 V, UVD = 20 V or any other minimum voltage the battery is allowed to be discharged to

•

Assumption: the battery has a voltage of 26 V at test start

•

DC inputs resp. DC outputs on all units switched off

1. Discharging the battery to 24 V 
Setup: Voltage on the power supply set to 24 V, DC output of power supply and DC input of load activated
Reaction: the e-load will load the battery with a max. current of 100 A in order to discharge it to 24 V. The power 

supply delivers no current at this moment, because the battery voltage is still higher than what is adjusted on the 

power supply. The load will gradually reduce the input current in order to maintain the battery voltage at 24 V. Once 

the battery voltage has reached 24 V with a discharge current of approx. 0 A, the voltage will be maintained at this 

level by charging from the power supply.

2. Charging the battery to 27 V 
Setup: Voltage on the power supply set to 27 V
Reaction: the power supply will charge the battery with a maximum current of 50 A, which will gradually reduce 

with increasing voltage as a reaction to the changing internal resistance of the battery. The load absorbs no cur-

rent at this charging phase, because it is controlled via the Share and set to a certain voltage, which is still higher 

than the actual battery voltage and the actual output voltage of the power supply. When reaching 27 V, the power 

supply will deliver only the current needed to maintain battery voltage.