|Using Isolation Diodes for Parallel-Redundant Operation
Typical Parallel Redundant Configuration showing Isolation diodes
For simple parallel operation of two (2) identical models there is no need for isolation diodes to be connected between the power supply and the load.
For Parallel Redundant Operation we recommend using a power diode in series with the output of each power supply as shown in the illustration. These diodes should have a current rating higher than the respective power supply output current rating and a voltage rating higher than the respective power supply output voltage rating.
For example, with two (2) RCW 24-31K models (24V, 31A) configured for parallel redundant operation, a Schottky diode with a Voltage Rating of 50V (minimum) and a Current Rating of 40 Amperes (minimum) is recommended.
The isolation diodes must be installed on a heatsink to maintain operating temperature at a safe level. The power dissipation on the diode is determined by the product of the current passing through the diode and its "on" diode voltage drop. We recommend using a Schottky diode instead of Silicon diode because it has a lower voltage drop and will run cooler.
Where the diodes come two in a package, they can be paralleled for lower voltage drop, or the diodes can be connected individually for each of the power supplies in the parallel redundant configuration.
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