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Rockwell Automation Publication 1606-RM101A-EN-P - July 2020
N+1 Redundancy
Redundant systems for a higher power demand are usually built in an N+1
method. For example, four power supplies, each rated for 10 A, are paralleled to
build a 30 A redundant system.
Leakage current, EMI, inrush current, and harmonics increase when using
multiple power supplies.
Keep an installation clearance of 15 mm (0.59 in.) (left / right) between two
power supplies and avoid installing the power supplies on top of each other. To
use power supplies in parallel, ensure the following:
•
The power supplies are in the standard mounting orientation (terminals
on bottom of the unit).
•
The power supplies are not in any condition where a derating of the
output current is required, such as altitude.
Wiring examples for 1+1 redundancy:
Figure 44 - Wiring for N+1 Redundancy with Four Power Supplies and Two 1606-XLERED20
Redundancy Modules
Inductive and Capacitive
Loads
The unit is designed to supply any kind of loads, including capacitive and
inductive loads. If large capacitors, such as EDLCs (electric double layer
capacitors or “UltraCaps”) with a capacitance larger than 1.5 F are connected to
the output, the unit might charge the capacitor in the HiccupPLUS mode (see
L
N
PE
30 A
Load
Failure
Monitor
I
Redundancy
Module
Output
Input
1
Input
2
+
+
-
-
+
-
opt
ional
Power
Supply
24V, 10 A
DC-
OK
+ +
- -
L N PE
Output
Input
o
o
Power
Supply
24V, 10 A
DC-
OK
+ +
- -
L N PE
Output
Input
o
o
I
Redundancy
Module
Output
Input
1
Input
2
+
+
-
-
+
-
Power
Supply
24V, 10 A
DC-
OK
+ +
- -
L N PE
Output
Input
o
o
Power
Supply
24V, 10 A
DC-
OK
+ +
- -
L N PE
Output
Input
o
o
I
I
