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Sensing for parallel operation – AMETEK XHR 1000 Watt Series User Manual

Page 56

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Local Operation
Using Multiple Supplies

56

Operating Manual for XHR Series Power Supply

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 set points to maximum. 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 20 V, 50 A power
supplies operating in parallel with a 75 A load, one supply operates in constant
current mode supplying 50 A and the other supply operates in voltage mode
supplying the remaining 25 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.

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 3.3 Parallel Operation of Multiple Supplies

(Local sense lines shown are default J2 connections.)