CHAPTER 13 PARALLEL AND SERIES OPERATION
13.1 Parallel operation
Up to 3 FPS-S1U racks with up to 8 FPS1000 installed units of the same output voltage rating can be connected in parallel. The built-in Oring diodes on the main output and on the +12V auxiliary voltage in each FPS1000 unit allow N+1 operation. By connecting the CS signal between the paralleled units, automatic current balance is achieved, with +/-10% accuracy. For input voltages less than 100Vac, maximum output Power derated by 10% of the Power rating. Refer to Fig 13-1 for output Power derating in parallel operation.
%of rated Power
100
90
| | | Input voltage |
| | 265 |
85 | 100 | (Vrms) |
Fig 13-1: Output Power derating at parallel operation
13.1.1 Parallel operation with Remote sensing
Fig13-2 shows typical connection of parallel operation with Remote sensing. The CS signal wires should be as short aspossible and with the same length.
FPS-S1U #1 | +V | | +S |
+S | |
| | | | | |
| | ON/ ON/ | ON/ | -S | | -S |
| SIG. OFF OFF OFF | -V | |
CS RTN | A | B | C | | |
9 | 11 | 5 | 15 | 25 | | | +S |
FPS-S1U #2 | +V | +S | +V |
+S | |
| | | | | LOAD |
| | ON/ ON/ ON/ | -S | |
| | -S | |
| SIG. OFF OFF OFF | -V | -V |
CS RTN | A | B | C | |
9 | 11 | 5 | 15 | 25 | | | |
| | | | | | | -S |
FPS-S1U #3 | +V | +S | |
+S | |
| | | | | |
| | ON/ ON/ | ON/ | -S | -S | |
| SIG. OFF OFF OFF | -V | |
CS RTN | A | B | C | | |
Fig 13-2: Parallel operation with Remote sensing