User Manual

Page 67
EA Elektro-Automatik GmbH
Helmholtzstr. 31-33 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
www.elektroautomatik.de
[e-mail]
ELR 9000 Series
3.9 Other applications
3.9.1 Parallel operation in master-slave (MS)
Multiple devices of same kind and model can be connected in parallel in order to create a system with higher total
current and, hence, higher power. The units are connected with their DC inputs, their master-slave bus and their
Share bus. The master-slave bus is a digital bus which makes the system work as one big unit regarding value
adjusted, actuals and status. The Share bus will balance the units in their internal regulation, especially if the master
unit runs a function like sine wave etc.
3.9.1.1 Wiring the DC input
The DC input of every unit in the parallel operation is simply connected to the next unit using cables with cross
section according to the maximum current and with short as possible length.
3.9.1.2 Wiring the Share bus
The Share bus is wired from unit to unit with an ideally twisted pair of cables with non-critical cross section. We
recommend to use 0.5mm² to 1.0mm².
The Share bus is poled. Take care for correct polarity of the wiring!
A max. of 10 units can be connected via Share bus.
3.9.1.3 Wiring and set-up of the master-slave bus
The master-slave bus is built-in and must rst be connected via network cables (≥CAT3) and then congured
manually or by remote control. The following applies:
• Type of connection: RS485 with 115200Bd
• Maximum 17 units can be connected via the bus: 1 master and up to 16 slaves.
• Only devices of same kind, i.e. electronic load to electronic load, and of the same model, such as ELR 9080-170
to ELR 9080-170.
• Units at the end of the bus must be terminated (DIP switch on the back side)
Later operation of the MS system implies:
• the master unit displays, or makes available to be read by the remote controller, the sum of the actual values
of all the units
• the range for setting the values of the master is adapted to the total number of units, thus, if e.g. 5 units each with
a power of 7kW are connected together to a 35kW system, then the master can be set in the range 0...35kW.
• resistance setting and control (CR) are not possible in active MS mode.
► How to connect the master-slave bus:
1. Switch off all units that are to be connected and connect them together with a network cable (Cat3 or bet-
ter, not included). It doesn’t matter which of the two master-slave connection sockets (RJ45, backside) is
connected to the next unit.
2. Also connect all units at the DC side:
Master-Slave
DC
E-LOAD n
E-LOAD 1
E-LOAD 2
Share Bus