34
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.
Fig 13-2: Parallel operation with Remote sensing
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.
LOAD
FPS-S1U #1 +V
+S
-S
-V
+S
-S
FPS-S1U #2 +V
+S
-S
-V
+S
-S
+S
-S
FPS-S1U #3 +V
+S
-S
-V
+S
-S
+V
-V
9
CS
11
SIG.
RTN
ON/
OFF
C
ON/
OFF
B
ON/
OFF
A
51525
9
CS
11
SIG.
RTN
ON/
OFF
C
ON/
OFF
B
ON/
OFF
A
51525
9
CS
11
SIG.
RTN
ON/
OFF
C
ON/
OFF
B
ON/
OFF
A
51525
Fig 13-1: Output Power derating at parallel operation
90
100
100 265
Input voltage
(Vrms)
% of rated Power
85