One is for your DC power lines, other is for your CAT 5.  

From: Mike Hammett 
Sent: Wednesday, May 10, 2017 5:28 PM
To: [email protected] 
Subject: Re: [AFMUG] Suppression Question

http://www.mccowntech.com/800-dcss-apc-rack-mount-dc-power-line-apc-rack-surge-protector/
 


vs

http://www.mccowntech.com/800-gige-apc-hv-rack-mount-gige-apc-hv-ethernet-surge-protector/

I'd assume the top one is better than the bottom on, but I don't know why.

It looks like the DC one actually costs a fair amount more, not that it would 
stop me.




-----
Mike Hammett
Intelligent Computing Solutions

Midwest Internet Exchange

The Brothers WISP






--------------------------------------------------------------------------------

From: [email protected]
To: [email protected]
Sent: Wednesday, May 10, 2017 4:43:53 PM
Subject: Re: [AFMUG] Suppression Question


Absolutely better in every way. 

From: Lewis Bergman 
Sent: Wednesday, May 10, 2017 3:39 PM
To: [email protected] 
Subject: Re: [AFMUG] Suppression Question

So I guess what I am asking is do you have an opinion if fiber plus dc only 
might be "better" in some way than poe?



On Wed, May 10, 2017, 3:32 PM <[email protected]> wrote:

  I guess my point is that you do not want MOVs for data.  
  The sidactors are extremely fast and they are on all my stuff.  
  Along with gas tubes, which are much faster than MOVs too.  



  From: Lewis Bergman 
  Sent: Wednesday, May 10, 2017 11:42 AM
  To: [email protected] 
  Subject: Re: [AFMUG] Suppression Question
  So Chuck, what is your opinion then? Looking at your site there is only about 
a $10 delta between the DC only and POE if I was looking at the right ones. Can 
you make an product to clamp faster without data on the lines or am I just 
imaging that? My thought was you could design it closer to 48 volts but most 
equipment draws a lot more than that on startup anyway.

  On Wed, May 10, 2017 at 10:21 AM <[email protected]> wrote:

    MOV is slow and bad for data but power
    SAD is fast but not robust
    Gas tube is robust

    I use all 3 on my power surge arrestor products.  

    From: Lewis Bergman 
    Sent: Wednesday, May 10, 2017 9:12 AM
    To: [email protected] 
    Subject: Re: [AFMUG] Suppression Question
    When I made the decision to the extent possible, eliminate CAT5 powered 
devices and go all fiber and 48VDC I based it on two things. 
    I found MOV/SAD combination devices for about $15 to protect the DC line 
compared to about ~$65 at the time for CAT5. Not only that, I found those 
devices speced faster clamp times. I assume since they did not have to worry 
about the voltage differentials of the data pairs. Chuck could obviously answer 
that one. This was a long time ago so I can't say what current pricing would 
be. I also found after converting to that that we had less, not zero, but less 
issues with the fiber plus DC with protection setup than the same equipment fed 
CAT5 POE with surge.

    We used all DIN mounted stuff.

    On Wed, May 10, 2017 at 10:02 AM Mike Hammett <[email protected]> wrote:

      *nods* I was hoping for a more sciencey and bean countery answer.  ;-)





      -----
      Mike Hammett
      Intelligent Computing Solutions

      Midwest Internet Exchange

      The Brothers WISP






--------------------------------------------------------------------------

      From: [email protected]
      To: [email protected]
      Sent: Wednesday, May 10, 2017 9:58:40 AM
      Subject: Re: [AFMUG] Suppression Question



      Any exposed conductor will have a voltage induced on it by lightning 
strikes.  Less conductors, less problems.  I would think fiber and power would 
be more robust than ethernet.  

      From: Mike Hammett 
      Sent: Wednesday, May 10, 2017 8:56 AM
      To: [email protected] 
      Subject: [AFMUG] Suppression Question

      This question is intended for Chuck and Forest, but I'll accept answers 
from anyone else qualified.

      I assume that the costs and complexities of doing surge suppression on a 
basic 48v DC power cable are much lower than doing so on a cat6 cable, trying 
to preserve GigE or above. Could you confirm that and perhaps back it up with 
costs, commentary, etc.?

      My point is to show that DC+ fiber not only is better for the data ports 
on both sides, but also for the tower equipment in general by being able to do 
more effective and less expensive surge suppression on raw DC than Ethernet.




      -----
      Mike Hammett
      Intelligent Computing Solutions

      Midwest Internet Exchange

      The Brothers WISP





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