Comparing two surge protection devices

[mikefamig]

Below are the specs for two Ditek surge protection devices that both are recommended to protect ethernet IP devices. It appears to me (with my limited understanding of electronics) that the MRJ45C5E offers better protection. Can anyone shed some light on these specs for me and what they mean? I have had an ehternet switch and a TV set-top box damaged by lightning in the past and s I'm trying to learn what I can about preventing more damage in the future.
 
                                DTK-110C6A                  DTK-MRJ45C5E  
service voltage            1 - 12 volts                               5    
mcov                             18 volts                                 6.5    
peak surge current      100 A/pair                           268 A/pair    
max cont current       1.5amp/pair                             0.3 amp    
clamping voltage          21.6 volts                                7.67  
 
I have also looked t the APC PNET surge protector but can not find comparable specs for it.
 
Mike.

 

[drvnbysound]

Had a few strikes near us last night. This was by 11pm, and it went on for a few hours after this too...

 

[mikefamig]

Cool technology....I use this
 
http://en.blitzortung.org/live_lightning_maps.php

 

[pete_c]

Here I have tried to do the best over the years.  I have much LV outside today.
 
Only the irrigation in two locations has been affected by lightning.  (well now protected).  One location continues to use stock stuff (and is not automated).  All I have seen there is fuses blown such that I replaced them.  The other location originally took out two irrigation controllers.  Fixed and protected haven't had an issue in over 5 years.  Old house bad grounding (1990's) I did lose a bunch of stuff with one lightning bolt (switches and computers) but never did lose my combo alarm panel there taking hits of lightning or high voltage.  (lucky?)
 
That said here originally built a 1-wire counter lightning sensor which still today does work and I look at those numbers and I could probably just use a script / trigger to warn me and sort of do that today with other weather stuff.
 
Not knowing the specifics as you have asked above Mike I would just do the best you can and cross your fingers that you have done well.

 

[mikefamig]

What I do know is that the lower continuous voltage, continuous and peak current and lower clamping voltage on the MRJ will protect my equipment better than the 110c6a. The question is if the higher 110c6a specs will provide adequate protection at the higher thresholds. I also am concerned that the MRJ will wear out and die quickly by absorbing.redirecting more current over time.
 
Mike.

 

[pete_c]

Yeah I have not paid attention to stuff installed over 10 years ago here.  I think it is working but really have no way to test it or whether it even works today.  I think it does work as I have seen neighbors here lose electrical stuff in recent years.
 
The largest surge protector here is on the fuse panel with it's own circuits / alarm outputs.  I went with a commercial style there. Way overkill but the prices was right.  It has triggered an alarm a few times over the years.  Looks like it keeps working.  It doesn't though have anything to do with other LV wiring and is only for the incoming electrical.  I did add another one for the outdoor HVAC compressor for HV only though.
 
All of the rest of the ingress of outdoor LV stuff here comes in to the home via one "d-mark" and I do utilize a ground stake right there.  No exterior building though.  IE: no garage or shed with anything in it.  Old house struck by lighting did have a detached garage and shed that was LV and HV wired.  At the time did what I could do relating to protection; that said didn't know back then what I know today about it.
 

 
I do watch lighting with incoming storms.  That said read that my lightning sensor has some 25 miles sensing radius.  Typically on an average day see less than 10 strikes of lighting.  Incoming storms register lightning strikes in to the thousands and it  happens really fast.  Took NOAA weather watching classes and typically if anything run outside / drive with camera to take pictures and don't really think much of what will happen should the house take a lightning strike.  (old age?).

 

[mikefamig]

  Took NOAA weather watching classes and typically if anything run outside / drive with camera to take pictures and don't really think much of what will happen should the house take a lightning strike.  (old age?).

I've thought in the past that it would be interesting to become a weather watcher.
 
I don't think that it's your age that has made you complacent, I think that it's the fact that you are not having any equipment damaged. A recent storm cost me $75 for a new IP switch and shortly afterwards the new switch froze up during a thunderstorm. Luckily it came back after cycling the power to it.

 

[pete_c]

It was just volunteering here and part of my other volunteering stuff.  Relating to the storm watching stuff; once a registered NOAA watcher; your NOAA reports say relating to a funnel cloud / touch down / pictures are validated by NOAA because you are an "official" NOAA weather watcher versus a lay person thinking that they are seeing a funnel cloud or whatever.  The classes are basically weather watching classes.  Simple stuff - common sense viewing vantage points et al.
 
Tried to automate weather and I just cannot do that these days. 
 
So I use my automation.  IE: outputs from a weather radio here go to the OP2 panel.  Triggers a chime and an alert on the automation software.  The automation software does a NOAA alert screen scrape which then uses text to speech to say the alert in the house.  It is just basic stuff.

 

[mikefamig]

Pete
 
Your PTE-160 is a 3 phase high voltage surge device. I'm working with 5 volt IP protocol over cat6 cable.
 
Mike.

 

[pete_c]

I know.  That is why I stated it is a HV surge protector.
 
Here just googling a bit found a statement that it is unknown how long a surge protector will last. 
 
That said it also states to replace them every two years.  This though is a general statement.
 
I have smaller serial port surge protectors that are inline and I think they have been connected now over 5 years; dunno if they are still good.  The serial pieces still work fine.

 

[mikefamig]

An interesting thing about my problem:
 
I installed the IP cat6 cable in a buried conduit in 2011 when the garage was built. It was fine until I added the Elk rs-485 cat6 cable to the same conduit in or around 2014. It is shortly after installing the Elk cable that the IP cable began taking lightning hits.
 
I am convinced that either of the devices that I listed in my original post will offer protection to the devices that I have on my LAN (stb. xbox, computers, switches) but would like to learn more about the specifications and what they mean. I understand that the lower voltage and amperage of the MRJ will allow lower voltage and current to pass through to my devices and that is a good thing but are there disadvantages to this? Why is the other device recommended for the same application when the specs between the two devices are so different?
 
Mike.

 

[drvnbysound]

Just curious, have you tried calling Ditek directly, speaking to a tech and asking the questions directly? I've done this many times to get clarification on information such as this, as well as their direct product recommendation based on the specific use case you have.

 

[mikefamig]

Just curious, have you tried calling Ditek directly, speaking to a tech and asking the questions directly? I've done this many times to get clarification on information such as this, as well as their direct product recommendation based on the specific use case you have.

 
Yes I have spoken to Ditek and was recommended the 110c6a but I wasn't aware of the MRJ at that point so we didn't compare the two. I'll have to give them a call back but I thought that it would be an interesting topic to discuss here and that I might learn something.
 
Mike.

 

[mikefamig]

I'm just off the phone with Ditek support and all of my questions have been answered. I have to say that the technical support in this security.HA industry is the best that I have experienced anywhere. I've been very impressed with Automated Outlet and Elk and now I'm adding Ditek to the top of the list. The rep that I spoke to was very knowledgeable, very patient and very helpful.
 
The short story......The two devices in my OP will both work to protect an IP network. For The IP data the service voltage is 5 volts so you need a device with a service voltage not less than 5 volts with maybe a few volts more for overhead. The clamping voltage can be as much as double the service voltage without damaging your devices on the network because it occurs for such a short duration of time. The peak surge current (which I did not mention above) is the amount of current that the Ditek can re-direct to earth without altogether failing.
 
I was wrong in worrying about the difference of ~10 volts between devices. When a surge occurs, the Ditek switches the over-voltage to earth so quickly that the 10 or 20 volts above service voltage is very short duration and will do no harm.
 
Mike.

 

[drvnbysound]

Did they recommend one device over the other for your application, or are you simply choosing on your own based on the information you were given?