What are the requirements of parallel connections? What are the differences between parallel and redundant?
When power supplies are connected in parallel, mostly, is intended to increase the output current. Due to the design of active current sharing, they are mostly without reverse current protection, therefore, they are not the best solution when talking about redundancy. For redundant purposes, please choose the PSU with redundant function or implement external redundant modules. Be sure that the difference in output voltage and wiring impedance, should be as small as possible.
1. Use PSP models as an example, connect P(LP/CS) terminals together (Please refer to the parallel function in the specification). Input and output should be connected in parallel before connecting to the AC source and loads. Shown as in the picture below (some specific power supplies require a minimum load after paralleling).
2. Output voltage difference between power supply units should be as small as possible, normally < 0.2V.
3. The power supplies should be paralleled with short and large diameter wiring together first, and then connected to the load.
4. After paralleling, the maximum usage of total power should be around 90% of the rated total power.
5. When the power supplies are paralleled, if the load is lower than 10% of the rated load of the individual power supply, the LED indicator or signals (Power Good, Pok, Alarm Signal) may malfunction.
6. To ensure that the load current is effectively shared in parallel operation, in general, it is recommended not to use more than 4-6 power supplies at one time. Please follow the maximum number of units as stated in the datasheet.
7. In some models, the +S, -S terminals should be used to reduce unstable pulsation of output voltage.