Rockwell Automation 1606-XLE240F-3 Power Supply Reference Manual - Manual (Page 20)

All parameters are specified at 24V, 2.5A, 230Vac input, 25ªC ambient and after a 5 minutes run-in time unless noted otherwise.
20 Rockwell Automation Publication 1606-RM031A-EN-P — April 2014
Bulletin 1606 Switched Mode Power Supplies
22.7. Inductive and Capacitive Loads
The unit is designed to supply any kind of load, including unlimited capacitive and inductive loads.
22.8. Parallel Use to Increase Output Power
1606-XLE240F-3 power supplies can be paralleled to increase the output power.
This power supply can also be paralleled with power supplies of the same
type. The output voltage of all power supplies shall be adjusted to the same
value (±100mV) in “Single use” mode with the same load conditions on all
units, or the units can be left with the factory settings. After the
adjustments, the jumper on the front of the unit must be moved from
“Single use” to “Parallel use”, in order to achieve load sharing. The “Parallel
use” mode regulates the output voltage in such a manner that the voltage
at no load is approx. 5% higher than at nominal load. See also section 6. If
no jumper is plugged in, the unit is in “Single use”. Factory setting is “Single
use” mode. A fuse or diode on the output of each unit is required only if you connect more than three units in
parallel. If using a fuse or circuit breaker, choose one with approximately 150% of the rated output current of the
power supply. Maintain an installation clearance of 15mm (left / right) between two power supplies and avoid installing
the power supplies on top of each other. Do not use power supplies in parallel in mounting orientations other than
the standard mounting orientation (input terminals on the bottom and output terminals on top of the unit) or in any
other condition where a derating of the output current is required (e.g. altitude, above 60°C, …). Please note that
leakage current, EMI, inrush current and harmonics increase when using multiple power supplies.
Unit B
-
+
Load
+
-
Fuse
Fuse
AC
DC
AC
DC
-
+
Unit A
22.9. Parallel Use for Redundancy
Power supplies can be paralleled for redundancy to gain higher system availability. Redundant systems require a
certain amount of extra power to support the load in case one power supply unit fails. The simplest way is to put two
power supplies in parallel. This is called a 1+1 redundancy. In case one power supply unit fails, the second is
automatically able to support the load current without interruption. Redundant systems for a higher power demand
are usually built in a N+1 method (for instance, five power supplies, each rated for 5A are paralleled to build a 20A
redundant system). For N+1 redundancy the same restrictions apply as for increasing the output power; see section 22.8.
Please note: This simple way to build a redundant system does not cover failures such as an internal short circuit in
the secondary side of the power supply. In such a case, the failing unit becomes a load for the other power supplies
and the output voltage can no longer be maintained. This can only be avoided by using the decoupling diodes
included in the 1606-XLERED decoupling module.
Recommendations for building redundant power systems:
a) Use separate input fuses for each power supply.
b) Set the power supply into “Parallel Use”.
c) Monitor the individual power supply units. A DC-ok lamp and a DC-ok contact is included in the 1606-XLERED
redundancy module. This feature reports a faulty unit.
d) It is recommanded to set the output voltages of all units to the same value (± 100mV) or leave it on the
factory setting.