Powerline Adaptors And Ring Mains.

[woodchopper]

On the current set up I have 4 powerline adaptors. 3 are on no.1 ring main (one adaptor being the "feed" from the router and the other 2, PC and set top box in separate rooms).
The 4th is on no.2 ring main. The 4th adaptor worked well for years with crossover from the 1st ring main but now doesn't at a rate which is useful.
It is not broken and works well putting it back on the no.1 ring main.
Only thing that was changed is the addition of 3 usb/wallsockets on the same ring main as the 4th adaptor.
Can i run a port from the router into the second ring main with another "supply adaptor"??