Instructions

Page 64
EA Elektro-Automatik GmbH
Helmholtzstr. 31-37 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
www.elektroautomatik.de
[e-mail]
PS 9000 3U Series
3.9 Other applications
3.9.1 Parallel operation in Share bus mode
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. To achieve that, the units have to be connected on their DC outputs and their Share
Bus. The Share Bus will balance the units in their internal voltage regulation and thus current regulation, which will
result in a balanced load distribution. It means that the Share bus is only e󰀨ective in constant voltage operation.
In the parallel operation, a specic unit, a “Share Bus master”, has to be picked as leading unit which drives the
“Share Bus slaves”. The master unit will remain fully controllable, also via analog or digital interface. The slaves,
however, are restricted regarding set value adjustment. Their set values are just limits for the units while it is con-
trolled via the Share Bus. A slave unit still can be controlled remotely, but not regarding output voltage. All slaves
can be monitored (actual values,status), no matter via analog or digital interface.
The Share Bus only control the process variable U (voltage). It means, the DC outputs of slave
units have to be switched on or o either manually or remotely, which is very easy in analog
remote control, because the related pins REM-SB could simply be connected in parallel, too.
Furthermore, the Share Bus makes the set values of current and power ineective on the slave
units, so it is recommended to carefully set the protection thresholds OCP and OPP.
3.9.1.1 Wiring the DC outputs
The DC output 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 0.5 mm² to 1.0 mm².
The Share bus is poled. Take care for correct polarity of the wiring!
A max. of 16 units can be connected via Share bus.
3.9.1.3 Conguring units for Share Bus operation
For correct Share Bus operation in parallel connection, the formerly picked master unit has to be configured as
“Share Bus master”. By default, these power supplies are set as “Share Bus slaves”, so that this configuration step
isn’t necessary for all slave units.
Only one unit in the Share Bus connection must be congured as Share Bus master, else the
Share Bus won’t work.
► How to configure a device as Share Bus master
1. Switch o󰀨 the DC output and push button to call the setup menu. Push again to enter sub
menu “Settings”.
2. In the sub menu navigate to “General Settings” and push once again.
3. Use arrow button to navigate to item “Share Bus mode” on the 2nd page and switch to setting “Mas-
ter” by using the right-hand rotary knob.
4. Accept the settings with or discard them with .
3.9.1.4 Operating the Share Bus system
After successful conguration and initialisation of the master and slave units, it is recommended to check all set
values and protection settings of all slaves and possibly adjust to identical values.
The slaves can be controlled manually as usual or remotely via the analog or via digital interfaces, but they don’t
react to voltage set values changes the same way as the master. They can, if needed, be monitored by reading
actual values and status.
The master unit isn’t restricted and can be used like a stand-alone unit.