Where should I use PNET1GB

[BillP]

I'm using my hs500 to surge protect between my Adsl modern and my router. I'm assuming I should get some PNET1GB but I'm not sure where and how many? Eg. The router is connected to a few nearby devices, but also has a long cable run to a switch which supplies various other devices.

Should the PNET1GB be used at one end of each cable, or both ends, and only if cables are over a certain length?

I'm also unsure about the earth wire - what should I connect this to, the only earth connections I'm aware of are in mains power sockets. Can I wire a 3 pin plug for earth only? Or should I connect to the back of the power socket?

[BillP]

i found this picture, i think it can help you

[Anonymous user]

Beware of the electromagnetic pulse (EMP) that comes from lightning. Just like high voltage power lines induce voltage in a fence running underneath it, when lightning strikes it induces voltage is long wires that are near by.

I just lost most of my network equipment (including PC motherboards, router, switches, and XBOX network ports) due to a lightning strike that did not directly contact my home, power lines, or cable (I don't have a phone line). All damaged equipment had a cable in excess of 25 ft connected to it. This includes my sprinkler timer and pump relay with a 100ft cable between them. All the network equipment and PCs were behind both a UPS and surge protector. I have a printer that was directly plugged into the wall (no surge protector) and was turned on, but it had no problems (and uses wireless ethernet). It seems that the voltage induced is not significant on a 120VAC circuit, but is very significant on a 5-24V circuit. (Note that Ethernet is 5VDC and the pump relay uses 24VAC.) I also wonder if my having so many UPSs and Surge protectors in my house may have themselves acted as a "whole house" surge protector. I have at least 5 UPSs, and 8 surge strips in use.

I recommend that some sort of surge arrestor be used on at least one side (if not both) of any network cable that is >50ft. In my case I have several devices on one side of the house, and several on the other, with one long cable running between two gigabit switches. So I will protect just downstream of the cable modem, and then on each side of my one long run.

Also, I'm not sure, but I think coax RGx cables are somewhat immune to the induced voltage since they have a shield which is grounded. Any induced voltage stays in the shield and doesn't make it to the signal wire in the middle, and is safely directed away to the ground. Again, I think this is the case. If this is correct, then a single point of entry protection should be enough, and I wouldn't worry about long cables within the home.

Message was edited by: Briago

Message was edited by: Briago

[BillP]

Thanks for the picture. Unfortunately I don't have anything with a screw to attach the earth (ground) wire to.

[BillP]

any surge protection does insert a bit of insertion loss. i know on APC's coax protection it is 2.3dB. a typical household receives 14dB of service so of course if you split it 4 times, thats 2.3dB each time probably.

i think any connection that you have coming in directly from outside should be protected but like for cable companies, i know they ground them right at the box. so you may not need it depending on what type of incoming connections you have and who provides them. you may just be giving yourself more un-needed insertion loss.

i think your TV set up is fine. i think what you are wanting to do might be a little overkill. if the outside connections are not grounded from your provider, you should probably put some surge protection the farthest upstream as you can, such as at your modem as I think you did or at your incoming connection.

hope that makes sense.

[BillP]

i think if you are protecting your model up at top of your "hierarchy" you shouldnt need to protect everything downstream. although, that will protect you from incoming surges and not necessarily surges originating from inside of your set up.

how many devices do you have total?

[BillP · Accepted solution]

There are 2 devices connected directly to the router, and 6 connected to the switch: 8 devices in total.

In the last few months I've added a few devices that aren't connected to APC UPS's, eg. Sony Bravia TV (which has Internet TV built in), Apple TV, and shortly I'll be getting a Humax FreeSat PVR (which will connect via ethernet). I have some basic surge protected power strips supplying these devices - is that adequate (eg. Belkin SurgeMaster)?

The Satellite cables aren't surge protected (should they be?, or with this cause loss of signal quality?) - presumably the network cable plugged into that device should be protected?