Kikusui PAD-L III Series, Operation Manual

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4-26 Applied Operation PAD-L
4.6 Master-slave-control series operation
It is possible to increase the output voltage by connecting several slave units in series
to one master unit. In a master-slave-control series operation system, a preset output
for all the units connected in series can be designated only from the master unit.
WARNING
• Be sure to observe the limitation on the maximum number of units
that can be connected in series. If the maximum output voltage
exceeds the isolation voltage, it may create a danger of electric
shock.
CAUTION
• Only identical TYPE models in the PAD-L series can be connected
in series to the master unit. Connecting different TYPE models of
the PAD-L series may result in failure.
• In case of master-slave-control series operation, the master unit,
slave unit 1, and slave unit 2 are started in this order. Thus, the
rise in output will be delayed in comparison with single-unit
operation. This may cause AC ripple components to be
superimposed on the output voltage. If rise waveform becomes a
problem, use a single high-output-voltage unit.
Number of units connectable in series:
The number of slave units to be connected in series is determined by the rated output
voltage and isolation voltage of each unit.
Taking the PAD35-50L as an example for series connection:
Since the rated output voltage is 35 V, and the isolation voltage is
±
250 V,
250/35 = 7.1, i.e., up to 7 units including the master unit can be connected in
series.
The rated output voltage and the isolation voltage are described in Chapter 7
"Specifications"
Presetting of OVP trip points in series operation
When carrying out series operation, OVP (overvoltage protection) trip points should
be preset for both the master unit and for all slave units.
In series operation, the OVP trip points for slave units should be set to slightly higher
values than that used for the master unit.
Set the OVP trip points as follows:
OVP set value of master unit
Rated output voltage of master unit
＜
OVP set value of slave units
Rated output voltage of slave units
If the OVP trip points for the slave units are preset to a value below that of the master
unit, their overvoltage protection will function first, turning off output from the
slaves but not from the master unit.