Parallel Operation - Omron S8VK-C Manual

Making Positive/Negative Outputs
 The outputs are floating outputs (i.e., the primary circuits and
secondary circuits are separated). You can therefore make
positive and negative outputs by using two Power Supplies.
You can make positive and negative outputs with any of the
models.
If positive and negative outputs are used, connect Power Supplies
of the same model as in the following figure. (Combinations with
different output capacities or output voltages can be made.
However, use the lower of the two maximum rated output currents
as the current to the loads.)
 Depending on the model, internal circuits may be damaged due to
startup failure when the power is turned ON if loads such as a
servomotor or operational amplifier may operate in series.
Therefore, connect bypass diodes (D
following figure.
If the list of models that support series connection of outputs says
that an external diode is not required, an external diode is also not
required for positive/negative outputs.
 Use the following information as a guide to the diode type,
dielectric strength, and current.
Type
Dielectric strength (V ) Twice the rated output voltage or above
RRM
Forward current (I ) Twice the rated output current or above
F
+V +V
L1
L2
−V
L3
0 V
+V
L1
L2
−V −V
L3
, D ) as shown in the
1 2
L1 +V
D
L2
1
−V
L3
L1 +V
L2 D
2
−V
L3
Schottky Barrier diode

Parallel Operation

Parallel operation is used when the output current from one Power
Supply is insufficient for the load. Power Supplies are connected in
parallel to increase the output current.
Two Power Supplies can be connected in parallel.
1. Parallel operation is possible only if the standard mounting and
3-phase input is used.
Maintain an ambient temperature of between -25 and 40°C.
2. For parallel operation, always use two Power Supplies with the
same capacity.
3. Use the output voltage adjusters (V. ADJ) to adjust the difference
in the output voltages between the two Power Supplies to 50 mV
or less.
4. If the output current from the two Power Supplies is not balanced,
the Power Supply with the higher output voltage will operate in an
overcurrent protection state, which will extremely reduce its
service life. After you adjust the difference in the output voltages
between the two Power Supplies, make sure that the currents are
well balanced.
5. The length and thickness of each wire connected to the load and
each unit must be the same so that there is no difference in the
voltage drop value between the load and the output terminals of
each Power Supply.
6. For Parallel Operation with units 120 W, 240 W S8VK-T Power
Supplies, connect diodes or S8VK-R to the outputs of each unit if
sudden load variation influence occurs in the ambient operation
environment.
Refer to the S8VK-R datasheet (Catalog No.: T059) for S8VK-R
specifications and the model number for each capacity.
7. The internal parts may occasionally be deteriorated or broken. Be
sure to set the OPERATION SWITCH to B when using S8VK-T
480 W, 960 W for Parallel Operation.
For Parallel Operation with units 960 W S8VK-T Power Supplies,
connect diodes to the outputs of each unit if sudden load variation
influence occurs in the ambient operation environment.
 Use the following information as a guide to the diode type,
dielectric strength, and current.
Type
Dielectric strength (V ) Twice the rated output voltage or above
RRM
Forward current (I ) Twice the rated output current or above
F
S8VK-T
S8VK-T S8VK-R
L1 +V +V
L2
IN 1
−V −V
L3
S8VK-T
+V
L1
L2
IN 2
−V
L3
+V
L1
L2
L3 −V
+V
L1
L2
L3 −V
Schottky Barrier diode
15