Ametek Sorensen XFR 1200 Watt Series, Operation Manual

Page: 71 / 106

Using Multiple Supplies
TM-F1OP-C1XN-01 3-13
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 3–7 .) 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, 30 A model power supplies operating in parallel with a 50 A load,
one supply operates in constant current mode supplying 30 A and the
other supply operates in voltage mode supplying the remaining 20 A. The
level of current sharing between units depends on how accurately the
output voltages are matched.
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.
Important:
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.
Figure 3-3 Parallel Operation of Multiple Supplies
(Local sense lines shown are default J10 connections.)
TM-F1OP-C1XN-01.book Page 13 Thursday, October 25, 2007 9:04 PM