American Magnetics 12200PS DC Power Supply (CE-Marked) - Manual (Page 41)

OPERATING MANUAL LOCAL OPERATION
Release 1.0 (98/07) 3-7
3.5.2 Configuring Multiple Supplies for Parallel Operation
Use parallel operation to obtain a higher current through a single output using two or more supplies. Set all of
the OVP setpoints to maximum. (See Section 3.3 Using Over Voltage Protection.) Set all of the outputs to the
same voltage before connecting the positive (+) output terminals and negative (-) output terminals in parallel.
See Figure 3.5-2. The total current available is the sum of the maximum currents of each supply.
When operating multiple supplies in parallel, the operating mode of each supply depends on the load current
being drawn. For example, with two 40V-70A power supplies operating in parallel with a 100A load, one supply
operates in constant current mode supplying 70A and the other supply operates in voltage mode supplying the
remaining 30A. The level of current sharing between units depends on how accurately the output voltages are
matched.
Note: If you do not fix the OVP setpoints at maximum, the OVP circuit may trip on one unit, reducing the
current available to the load.
Sensing for Parallel Operation
Use default local sensing to enhance power sharing between units, as the impedance of the load lines will tend to
correct for current imbalance. If you use remote sensing at the load for better voltage regulation, one supply
always operates in current limit mode and supplies most of the power.
Figure 3.5-2 Parallel Operation of Multiple Supplies
(Local sense lines shown are default J10 connections.)