@savatreatabr, I hope you're not totally confused by now.
Just use an 8 port gigabit POE+ switch with uplink port (9 total ports) or add a gigabit 4 or 5 port POE+ switch to your existing 8 port gigabit POE+ switch, run ONE cable from building B through conduit to the NVR in building A.
BTW, just to clarify, if no uplink port is provided or available you can use a POE port; an uplink port provides data only and no POE; a POE port provides both. When you connect a 802.3af/at compliant POE switch (PSE) to a non-POE device, there will be no negotiating and no power will be sent to the non-POE device by the POE switch, so no problem.
Insure cable jacket is rated for flooded/direct burial and is pure copper, not CCA (Copper Clad Aluminum).
Just use an 8 port gigabit POE+ switch with uplink port (9 total ports) or add a gigabit 4 or 5 port POE+ switch to your existing 8 port gigabit POE+ switch, run ONE cable from building B through conduit to the NVR in building A.
BTW, just to clarify, if no uplink port is provided or available you can use a POE port; an uplink port provides data only and no POE; a POE port provides both. When you connect a 802.3af/at compliant POE switch (PSE) to a non-POE device, there will be no negotiating and no power will be sent to the non-POE device by the POE switch, so no problem.
Insure cable jacket is rated for flooded/direct burial and is pure copper, not CCA (Copper Clad Aluminum).