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© 2006, Elektro-Automatik GmbH & Co. KG
Irrtümer und Änderungen vorbehalten
EN
Instruction Manual
PSI 8000 2U Series
Date:04-26-2011
Using the power supply
Attention! The system master must always be the unit with
the lowest potential!
There are some restrictions and rules to consider because of
safety and isolation reasons:
•
The negative DC output pole of no unit in the series
connection may be raised to a potential >300V against
ground (PE)!
•
The Share bus must not be wired!
•
The grounds (AGND, DGND) of the analogue interfaces
of the units must not be wired to each other!
•
Remote sense must not be wired!
Example: Two identical units with 360V nominal voltage, for
example PSI 8360-15 2U, shall be connected in series. When
calculating, the total voltage of that series connection could go
up to 720V. Looking at the resulting potentials on the negative
outputs of the units, the 2nd unit‘s negative DC pole could be
raised to 360V. This is not permitted! So the lower unit has to
be limited to a certain maximum. The figure below clarifies that
the resulting total voltage would be 660V:
Caution! A total voltage of a series connection of 600V
should not be exceeded!
10.4.2 Parallel connection in Share Bus mode
Note: only available with devices from 1kW nominal power!
Attention! Only units of the same type (voltage and current)
must be used for this operation mode.
Share bus operation is used to gain a symmetric load current
distribution when running multiple units in parallel connection.
Follwing connections are required: connect all (+) DC outputs
of the units to each other and all (–) DC outputs to each other.
Pin 7 (Share Bus) and pin 8 (Ground) of terminal
System Bus
of all units are also connected in parallel. In case remote sense
is also required, all Sense+ and all Sense - inputs are connected
in parallel and also with the load.
Important
: in this operation mode, the unit with the
lowest
output
voltage controls and defines the output voltage of the whole
parallel connection. It means, any unit of the system could be
in charge. Thus it recommended to pick a unit that is used to
control the whole system, while the set value of voltage for the
remaining units is set to the required minimum. Voltage and po-
wer set value could be set to 100% or, if not desired, set to equal
values on every unit so that the total results in what‘s required.
All units displays their actual values, there will be no totals
formation of the system output current.
In order to control the whole system remotely, it is sufficient to
control the master via its analogue or digital interface. When
reading actual values, the voltage monitor value will represent
the overall system voltage, but the current monitor only the
output current of the master. In order to get accurate readings,
either the actual current is multiplied by the number of units in
the parallel connection (only applicable if all have the same no-
minal output current) or all units will have to be read seperately.
For an example wiring see figure 11.
Figure 10. Series connection in Master-Slave
