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I'm analyzing how to best protect a setup comprised of a NAS/Router/Wimax from power surges. A very simple diagram is this:

When I write "dual source" (term which I just invented) I mean that the surges could come from either the 220V or the Antenna.

SoHo scenario: my main objectives is to protect the NAS & Router from surges, blackouts and brownouts. A bonus would be to keep my internet up & running during outages. Of course the underlying objective is not to degrade my data line.

So far I have found 5 options of my setup:

  1. I connect to an UPS the Router & NAS AND break the data connection between the PoE and the Router with the UPS. This should solve my main objective completely: Router and NAS will be safe and at the most, the PoE injector/antenna will be fried.
  2. I connect to an UPS the Router & NAS AND break the data connection between the PoE and the Router with the UPS AND I use a ethernet surges protector between the antenna and the PoE. This should solve my main objective completely and add extra security.
  3. I connect to an UPS the Router & NAS & PoE. My fear is a surge coming from the antenna and killing everything. However this is based on the assumption that the surge can jump from two of the UPS output outlets.
  4. I connect to an UPS the Router & NAS & PoE AND I use a ethernet surges protector between the antenna and the PoE. This should solve in theory everything.
  5. I connect to an UPS the Router & NAS & PoE AND I use a ethernet surges protector between the antenna and the PoE AND break the data connection between the PoE and the Router with the UPS. This should solve in theory everything and add extra security.

All three appliances have an external adapter. The UPS is likely to be an approximated sine wave (like the APC Backups Pro). Surge protector something like the PNET1GB. The antenna doesn't appear to be connected to ground with a dedicated cable. It's like one of these:

So the questions:

  1. What is the best setup in terms of protection? Among the ones presented or any new one.
  2. Can surges actually come from the antenna?
  3. is it useless to break the data line twice? (surge protector between antenna and PoE and UPS between PoE and Router)
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closed as off-topic by brhans, ThreePhaseEel, Sparky256, Voltage Spike, PeterJ Dec 31 '17 at 13:09

  • This question does not appear to be about electronics design within the scope defined in the help center.
If this question can be reworded to fit the rules in the help center, please edit the question.

  • \$\begingroup\$ Hi and welcome to EE.SE. I've added your sketch to your question(s). Feel free to edit it to put it in line with the text. However, your question(s) will probably be closed as too broad. Can you narrow it down a bit? \$\endgroup\$ – winny Dec 30 '17 at 10:28
  • \$\begingroup\$ Thanks. Tried to make it less broad. I can just hope it won't be closed :) I'll set a nice bounty in two days to reward. \$\endgroup\$ – JoeSlav Dec 30 '17 at 12:02
  • \$\begingroup\$ You seem to be confused about the role of a UPS. Its job is purely to provide short term battery backup in the absence of mains power. Either you want to do that or you don't. \$\endgroup\$ – Finbarr Dec 30 '17 at 12:20
  • \$\begingroup\$ @Finbarr: I think UPSes supply power surges protection too, no? \$\endgroup\$ – JoeSlav Dec 30 '17 at 12:49
  • \$\begingroup\$ @Sparky256: great info, thanks! I assume the surge protectors would be before the UPS? \$\endgroup\$ – JoeSlav Dec 31 '17 at 8:22
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As a former builder of UPS's for APC and other companies, the UPS has limited surge suppression, often just a single 20 mm MOV on the AC input. A serious and somewhat expensive surge suppressor will have many 40 mm MOV's in parallel on each phase and neutral to ground. Use the UPS for what it does best and buy separate surge devices for point-of use protection.

The more expensive suppressors will also have X and Y rated capacitors for basic noise filtering. Do NOT have the UPS run large motors as their lumpy sine-wave output can make the UPS fail.

Install suppressors before and after the UPS. They work best at their point of use. Every foot of wire to the suppressor adds another 100 volts peak to any surge that tries to get through.

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  • \$\begingroup\$ Sparky256: Thanks. Just to further clarify. Do you mean one like one of these: APC surgearrest? \$\endgroup\$ – JoeSlav Dec 31 '17 at 14:05
  • \$\begingroup\$ Sparky256: and what do you mean by "They work best at their point of use" ? and "every foot of wire adds..." is this good or bad? Thanks! \$\endgroup\$ – JoeSlav Dec 31 '17 at 14:11

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