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DOC-MN-007-03 VCCM600 User Manual
Vox Power Limited | Unit 2, Red Cow Interchange Estate, Ballymount, Dublin 22, D22 Y8H2, Ireland | T +353 1 4591161 | www.vox-power.com
Parallel Connected Outputs
VCCM output modules of the same type can be paralleled within the same product to achieve higher output currents. Links for paralleling modules are available
directly from Vox Power or our local representatives.
The following instructions must be followed for output modules configured in this manner.
When paralleled, the outputs can operate in two distinct modes, Normal parallel mode or Share parallel mode.
Normal Parallel Mode
For normal parallel mode, the positive power cables should be connected together and the negative power cables should be connected together. No other
connections are required as shown in the diagram below.
In this mode, the highest adjusted output module will supply all of the load current until its current limit is reached. If the load demand exceeds this level the
output voltage will drop to the level of the next highest adjusted module and that module will begin to supply the load current while the first module continues
delivering full current. This process repeats for the total number of paralleled modules. The diagram above shows the VI curve for such a system.
Output modules that are not delivering current will typically sink a small amount of current from the other outputs, but this will not exceed -6% of each module’s
maximum rated current.
Typically, system reliability is reduced in this mode as the higher adjusted modules will do most of the work with the lower adjusted modules only delivering
current during peak load demand.
Share Parallel Mode
In share parallel mode, the outputs are paralleled as before and the I
CONTROL
pin of each module connected together as shown in the diagram below.
Connecting the I
CONTROL
pins together forces all the outputs to deliver the same current, ensuring that the system reliability is maximised and the work load is
distributed evenly across all paralleled modules.
In this mode, the lowest adjusted output module will determine the actual output voltage and all higher adjusted outputs will reduce their voltage.
The current output signal (I
CONTROL
) can still be used to measure the output current but it must be scaled by N, where N is the number of paralleled modules.
WARNING!
Energy Hazards may arise when individual modules are paralleled. See the Safety section for more details.
When modules are paralleled, their inhibit lines (J3), if used, should also be paralleled. Inhibiting paralleled modules individually may cause damage
