43
Instruction Manual
PS 8000 DT Series
EN
Date: 03-05-2016
Operating the device
There are some more restrictions and rules to consider because
of safety and isolation reasons:
•
No negative DC output pole of a unit in the series con-
nection may be raised to a potential >300 V 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 360 V nominal voltage, for
example PSI 8360-10 DT, shall be connected in series. When
calculating, the total voltage of that series connection could go
up to 720 V. Looking at the resulting potentials on the negative
outputs of the units, the 2nd unit‘s negative DC pole could be
raised to 360 V. 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 660 V:
11.1.2 Parallel connection
Note: only available with devices from 1 kW nominal power!
Attention!
Only units of the same type (voltage and current) must
be used for this operation mode.
In order to increase the output current, two or more units of the
same type can be connected in parallel, using the Share bus
connection.
Following 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. Also see the example wiring
in figure 9.l
Important: in this connection the unit with the lowest output
voltage determines the output voltage of the system. It means,
that every unit can be in control, depending on the adjusted
values. It is thus recommended to select a unit that shall control
the system and adjust the set of the other units to maximum.
Note
In case a unit malfunctions or fails due to overheating (OT)
or overvoltage (OVP), the whole system can‘t provide power
anymore until the failure is removed.
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 nominal
output current) or all units will have to be read separately.
Figure 9. Parallel connection with Share Bus