Multiple power supplies


Is there any definitive documentation on connecting multiple power supplies to a system? I will have two boards each with their own PSU, along with a separate supply for input modules.


Just make sure that you link the ‘-’ of all PSU’s together and make sure that you do not link any of th ‘+’ of the PSU’s together.

Perfect, just was I was expecting. But I wasn’t sure whether the bus wires did this “automatically”.

i think this is possible when you use a relay that switch between powersupplies if the main one fails. e.g main supply switch a relais on ----> power to velbus by main power supply. failure of main supply switchs relay of and power backupsupply and set power to velbus.

hope this will be useful.


[quote=“wexfordman”]Would I be right in thinking that the dc power supply, is the only single point of failure in a velbus system ? If for example I have only one psu, and it goes, does that mean my entire system is down ? Is it possible to wire in a standby power supply to avoid this ?


We have setup 2 types of redundant power supplies, the first one has no battery backup, the second one has. See in the VelbusSpecific section at the custom projects