Question

Hello! I've got a RUT240 that works great. I would like to power it over passive PoE 24v, ideally with redundant wall plug power as well.

The wiki manual says that "The router can be powered from a power socket and over Ethernet simultaneously. In this case, both PSUs should have similar output voltages." 

In my case, the voltages would be 24v and 9v which I guess are pretty dissimilar... What are the potential problems here? If I try it out and it works, is it ok then? Will I destroy my RUT240, my 9v wall plug, my PoE switch or all of them?

Also, the data sheet at https://teltonika-networks.com/downloads/en/rut240/RUT240-Datasheet.pdf says that "Passive PoE over spare pairs (available from HW revision 0007 and batch number 0010)". What does this mean? I bought my RUT240 last year. Is it possible that it does not support PoE at all?

Answer 1

Hi,

In RUT 2xx and 9xx, both power source are connected in parallel, so if you are using PSU with different voltage it will put load on the 'weaker' PSU. It will not break the router, but most likely it will break the 'weaker' power source.

(FYI This limitation is removed in RUTX series)

You could check the device status in status>device. If the version number is smaller than HW revision 0007 and batch number 0010, then it will not support POE.