Xantrex Technology XFR 2800 - Manual (Page 68)

Local Operation
Using Multiple Supplies
66 Operating Manual for XFR 2.8kW Series Power Supply
sum of the maximum voltages of each supply (add voltmeter readings, to a maximum
of 600 V). The maximum allowable current for a series string of power supplies is
the output current of a single supply in the string.
Figure 3.2 Series Operation of Multiple Supplies
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 “Using Over Voltage
Protection (OVP)” on page 61.) Set all of the outputs to the same voltage before
connecting the positive (+) output terminals and negative (–) output terminals in
parallel. See Figure 3.3. 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 40 V, 70 A power
supplies operating in parallel with a 100 A load, one supply operates in constant
current mode supplying 70 A and the other supply operates in voltage mode
supplying the remaining 30 A. 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.