Hi, i have availability of cat6 shielded awg23 solid copper cable from a family member. If i use the correct rj45 plugs is this ok to use for running to my cameras? I understand the basics of grounding, so if both ends are terminated correctly do i need to do anything else or buy special routers etc....?? Thanks in advance
Steve
Hi Steve,
The cable you have is of an excellent quality.
If you have in mind to use Ethernet Surge protectors, yes, it makes absolutely sense to use an STP (Shielded Twisted Pairs) Ethernet cable, possibly cat 6+ or cat 7 if the cameras are PoE (Power over Ethernet). The cable you have, is even better than an STP, it's an SFTP (Shielded Foiled Twisted Pairs) cable, that on top of the Screen (a metal braid around the whole cable...) also has each Twisted Pair wrapped (screened) with foil, so even better quality. The problem with your cable is that is a 'trunking cable' with solid copper conductors (very stiff), which is normally used to connect (almost linearly) Ethernet patch panels with a certain type or RJ45 connectors; most of times 'keystone' RJ45 connectors which accept solid metal conductors, and require a tool to insert the solid wires in the Pairs into the RJ45 connector, so using the cable you have to CRIMP screened RJ45 PLUGS on it: good luck with that...RJ45 plugs (even the screened good quality ones) do not accept solid wires and the crimps tool struggle with them. By the way, if somehow you can sort out the problem, good for you.
About the Screen connection. You're right, screens should always be connected on both ends to be "effective", since:
- a screen connected to BOTH ENDS, protects against MAGNETIC FIELDS and ELECTRIC FIELDS
- a screen connected to ONE END only, protects against ELECTRIC FIELDS only.
Connecting one end of the screen only, is rather a legacy thing, and was used in very harsh environments (like Railways), where ground loops were a thing...they aren't so much anymore, but still happens to find signal equipment with the cable screen connected to one end only, when entering a Signal Room...that cable is probably there since 20+ years...
About the scheme that you've published, it's correct, everything in the scheme with a "blue shield" on it, is shielded and therefore protected by lightnings, including the Ethernet cable of course)...with exception of the RJ45 connector on the Camera. They haven't a screened RJ45 connector, since they have no ground connection and therefore a screen can't be connected anywhere. In event of a lightning that strikes the metal pole where the camera is installed, the camera is normally in a plastic box and its internal circuitry SHOULD be of the "double insulation" type, so the camera is protected, together with the wires in the Twisted Pairs connected to its RJ45 connector.
The problem is when the lightning strikes the Ethernet cable or the metal pole, in which case there are chances that it could indirectly couple into the Twisted Pairs of the Ethernet cable in form of a Surge, which has a VERY high energy and could possibly lead to disruption of equipment connected inside your house. In such case the screen around the Ethernet cable, and those Surge suppressors do the job. The first thing that the lightning would strike, would be the screen around the Ethernet cable, which is connected to ground to both ends by means of those suppressors.
Least but not last:
1) make sure to use screened RJ45 PLUGS on all of the Ethernet cables from the Camera until the router NVR, DVR or wherever you connect the Ethernet cables coming from the cameras outside in your house. Also make sure that on top of screened RJ45 ports (they're normally equipped with them...) the router, or wherever you connect your cameras, has a good connection to ground (a dedicated earth stud or a wire in the mains/power supply, or both...).