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JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5

[Electrical] Need help with surge/lightning damage

Scroll to bottom of post if you want tl;dr summary.

So last night this area got some major storms. I was up in Atlanta so I'm hearing about all of this 3rd party. Apparently, lightning hit close to the house (how close I don't know, supposedly it "shook the house") and caused the power to go off for a few seconds. Everything is connected to decent quality surge strips and/or battery backups.

From what I'm told, one computer started smoking and was promptly unplugged (though it works fine now). The HP switch mounted under my desk (well away from the smoking computer so I know the smoke wasn't from the switch) is toast. It's got a lifetime warranty and isn't the first time they've replaced one due to damage like this.

Anyway, I've been thinking. At my desk are two battery backups, both APC models. One is an SU700NET the other is a BR1300LCD. The SU has only the cable modem, HP switch and D-Link AP connected to it. The BR has just my PC connected but also has a long power strip connected to one of it's surge only ports that the rest of the stuff on the desk connects to.

Both of these battery backups have a screw on the back labeled TVSS Ground. I assumed the surge protection used the ground wire in the input cable but since this isn't the first time I've had surge/lightning damage here I'm wondering if I need to connect a ground to this screw? I assume I can tie it to the house ground and should not sink a specific ground rod for this (different potentials)?

The first surge came in through the coax I assume (cable modem and several TVs were dead) so I re-routed my incoming line through the coax ports on the BR UPS (it surprisingly works and doesn't block the cable modem's return path). This time no cable related equipment was damaged but maybe this surge didn't come in via the coax, hard to know.

I do want to get another whole-house surge protector and put on this panel (I do have one on the sub-panel in the shed where my servers are) but I'm wondering if I need to do something else too. Another thing I thought about is the Ethernet lines leading out to the shed (I have 4 Cat 5e lines running out there). I have in my possession a Porta 581P2 25-pair Building Entrance Protector. Will this help and do I need one on each end of the run?

tl;dr - Had more surge damage last night. Do I need to connect TVSS Ground screw on UPS to a ground source or does it use the input cable for that? Also, given I have 4x Cat 5e lines run out to a detached shed do I need surge protection on those lines and if so do I need it on each end of the run?


mackey
Premium
join:2007-08-20
kudos:13

[Electrical] Re: Need help with surge/lightning damage

It uses the input cable. That screw is so you can ground external surge protectors to it.

BTW, it may not have "come in on" any wire; I had the ethernet ports blown out on a cable modem and the router it was connected to, but both otherwise both still worked fine (cable modem using USB and a new WAN port assigned to the router using 3rd party firmware). Nearby lighting strikes emit a rather large EMP...

/M

JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5
Ahhh, that's an interesting thought about connecting additional surge protectors to it.

As for the EMP, that's certainly true. In the first case, the strike was somewhere down the street. Yet, one of the oddities resulting from that was my stereo going back into demo mode (it doesn't go into demo mode just from a power outage, it has to be put in demo mode). I can only assume an EMP did that. I don't know where this strike actually was (one person's "close" or "on the house" is another persons "way down the street").


mackey
Premium
join:2007-08-20
kudos:13
I just say if there's no noticeable delay between the flash and the BOOOOOOOOOOMMMMMMMM! it's way too close for comfort!

/M


tschmidt
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join:2000-11-12
Milford, NH
kudos:9
Reviews:
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reply to JoelC707
When it comes to surge protection think of your house as a bank vault. The idea to to prevent surges from passing the perimeter.

1) First step it to make sure residence has a good Earth connection, either Ground rod made electrode or city water pipe. Preferably both.

2) Make sure everything coming into the residence is bonded to that ground, Electricity, Telephone, Cable, External Antenna. You said surge came in via Cable, did the Cable provider connect cable shield to ground where it enters building?

3) Each service should have its own surge protector: telephone already has one, you should add one for Electricity and Cable.

4) Sensitive devices can be protected by point-of-use surge protectors. It is important that all conductors likely to be affected by surge run through the protector. It is the difference of potential between two or more conductors that kills electronics. Think if the difference between a bird on a power line vs a fried squirrel climbing a utility pole.

If the computer let out magic smoke you should assume something got damaged and fix it before the next storm.

/tom


stevek1949
We're not in Kansas anymore
Premium
join:2002-11-13
Virginia Beach, VA
reply to JoelC707
Are you using the entrance protection on both ends of the Cat5 runs?

If so, are both protectors bonded to ground?

Is it straight Cat5 or a multipair run? Buried or in conduit?

Are you using solid state modules in the protectors? The gas modules are too slow, but the SS will not protect from a near strike anyway!

Just asking basic questions, probably I should assume the answers.


John Galt
Forward, March
Premium
join:2004-09-30
Happy Camp
kudos:8

2 recommendations

reply to JoelC707
Grounding system and conductor impedance is an issue. Almost any house does not meet the requirements for "good grounding and bonding practices" for EMP protection.
You're dealing with something that has an exceptionally fast rise time and large voltage differentials.

Local lightning strikes are very difficult to defend against...
--
A is A


JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5

1 recommendation

reply to JoelC707
Gotta run here in a few so I'm going to make this quick.

Cable inbound is connected to the ground rod. There's no telephone as we all have cell phones so nothing to ground there. Only thing coming in is basically cable and power. There is only one ground rod at the pole where the meter is. That's all the electrician installed when he hooked everything up. No water ground as the water pipes are all PVC. I believe we are supposed to have a second rod (or water ground) but there are no inspections here so there was no opportunity for it to get flagged.

I do plan to investigate the smoke on the computer but I have a good idea what it was: the onboard NIC. The person that regularly uses it reported that it showed no network adapters present but he doesn't know everything to do with computers and probably overlooked it. Still, it's a good place to start given the switch it was plugged into is now dead.

The run to the shed is in 1/2" conduit for the outside portion of it's trip. It's four individual Cat 5e cables connected to a patch panel in the shed and keystone jacks under my desk in the house. The entrance protector is not in use currently and I have only one. I'm not sure if I need two (one for each building basically) or if one will suffice. The unit is quite old (I've had it for over 10 years) so I don't know if the modules are gas or solid state. Is there a way to tell the difference without opening them?

I understand that a direct (or even very close) strike is basically a case of you're SOL no matter what you do. Either from the high differentials or the EMP or both. I'm just wondering if there is something more I can do or aside from a few basic things like adding another whole house surge protector, am I doing everything possible already and anything beyond that will just lighten my wallet and not help me.


stevek1949
We're not in Kansas anymore
Premium
join:2002-11-13
Virginia Beach, VA

1 edit
said by JoelC707:

I don't know if the modules are gas or solid state. Is there a way to tell the difference without opening them?

The end of them should show a S or a G depending if it is Solid State or Gas. I use Circa modules.

You should have two protection modules, one at either end.

JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5
Don't see an S or G on them but they are imprinted with several letters and numbers. Googling reveals they are gas models. 75BCXN-230.

I suspected I would need two, will one help me short term until I can get the spare funds to buy a second? If so, where would be the ideal placement, the shed or under my desk? Is this even worth doing or am I better of spending money on something else?


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom

1 edit
reply to JoelC707
How do you properly size the transient voltage surge suppression TVSS for lightning strike potential?

Proper Transient Voltage Surge Suppression (TVSS) sizing as stated in UL1449, 2nd Edition, February, 2007 is based on the Short Circuit Current Rating (SCCR) of the electrical panel to be protected. All you need to do is find the Short Circuit Current Rating (SCCR) rating of the panel, and install a Transient Voltage Surge Suppression (TVSS) system equal or greater in rating. The Over Current Protection Device (OCPD) or circuit breaker must be installed in accordance with manufacturer's requirements. If the Over Current Protection Device (OCPD) rating is not stated, it is to be sized based on the units supply conductors. Transient Voltage Surge Suppression (TVSS) systems must also be installed on the load side of the panel, which generally means to install the Over Current Protection Device (OCPD) at the top of the panel closest to the primary feed.It is of course important to remember that Transient Voltage Surge Suppression (TVSS) systems in particular require good grounding, as the surge will be dumped directly to ground (which is unlike a regular surge protectors that use the neutral as well as the ground). In fact, there are some serious concerns about installing Transient Voltage Surge Suppression (TVSS) systems without proper grounding, as it may be more dangerous to install them on ungrounded systems than if they had not been installed at all.

Adherence to NEC Article 250 is very important. We recommend that you have at least two (2) dedicated 10-ft ground rods installed at the panel and in compliance with NEC 250 for your TVSS system.

Here are a few of the codes that relate to your task:

National Electrical Code NEC Article 240.4 requires that Transient Voltage Surge Suppression (TVSS) be installed with an Over Current Protection Device (OCPD) such as a circuit breaker.

NEC Article 310.15 requires that the Over Current Protection Device (OCPD) be properly rated to the size of the TVSS feed conductors, even if it is not listed on the device.

NEC Article 285.6 requires that the Short Circuit Current Rating (SCCR) of the Transient Voltage Surge Suppression (TVSS) be greater than the Short Circuit Current Rating (SCCR) of the panel to be protected.

NEC Article 250 requires proper grounding and is especially important for Transient Voltage Surge Suppression (TVSS) installations.

Read this also good info

TVSS Lightning and Equipment Protection

JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5
Not sure what you're pointing out but thank you for the info. Is it in regards to the TVSS on the UPS or the ground rod situation or what? I checked the SCCR of the inside panel in the house, it's 22,000. I don't know about the panel in the shed or the panel on the pole but I suspect they are similar.


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
I'm pointing out as the article says TVSS for lightning is different than your surge suppressors that use the neutral as well as ground to control "surges".

»www.progress-energy.com/assets/w···tion.pdf

guppy_fish
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join:2003-12-09
Lakeland, FL
kudos:3
Reviews:
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reply to JoelC707
Your long CAT5 runs are huge antennas for picking up induced EMF, there isn't much you can do and any near buy strike will be coupled into your wires.

The only sure fire way to not have this issue is run fiber and have Ethernet converters on each end.

Google Fiber Media Converts

JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5
reply to Jack_in_VA
Ahhh good point. Basically what you're saying is I'd need something that could shunt 22,000 amps somewhere and no circuit in this house could do that. So basically don't worry about lightning and worry about the surges (I'm fairly covered there and know where I need to improve there, such as the whole house surge protection inside the house).

JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5
reply to guppy_fish
All of my switches have SFP modules so I could do fiber directly. Will have to look into that for sure as it would remove the issue completely.


tschmidt
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join:2000-11-12
Milford, NH
kudos:9
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said by JoelC707:

I could do fiber directly.

Fiber is a great way to harden your system to lightning.

In regards to what Jack_in_VA See Profile posted surge protection does not absorb and dissipate transient energy, it diverts it. That is why proper grounding and bonding is so critical. Ohms law and AC impedance conspire to create large voltage difference over of few feet of ordinary conductors during surge events. This difference in potential is what lets out the magic smoke of your expensive electronics.

/tom


Maxx2006

join:2013-02-02
Cambridge, ON
kudos:2
reply to JoelC707
Took a surge a few years ago loss the cable box and HDMI ports on the two tv's. I have since used this setup
»www.lowes.com/pd_103219-82364-CH···=3006037

Do remember that surge protection will only take so many hits then fail. At work we have used stuff from Honeywell to protect hydro panels.


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
said by Maxx2006:

Took a surge a few years ago loss the cable box and HDMI ports on the two tv's. I have since used this setup
»www.lowes.com/pd_103219-82364-CH···=3006037

Do remember that surge protection will only take so many hits then fail. At work we have used stuff from Honeywell to protect hydro panels.

Keep in mind that surge protection and lightning strike protection are not the same.

quote:
Transient Voltage Surge Suppression (TVSS) systems must also be installed on the load side of the panel, which generally means to install the Over Current Protection Device (OCPD) at the top of the panel closest to the primary feed.It is of course important to remember that Transient Voltage Surge Suppression (TVSS) systems in particular require good grounding, as the surge will be dumped directly to ground (which is unlike a regular surge protectors that use the neutral as well as the ground)


whizkid3
Premium,MVM
join:2002-02-21
Queens, NY
kudos:9
reply to JoelC707

Re: Need help with surge/lightning damage

For sure, a voltage 'surge' went through the low-voltage wires to your computer. I had something similar happen, when a lighting strike hit the pole outside and traveled into the house through the telephone line. I was talking on the telephone at the time. The only thing in-between was my computer modem which took the hit. There was an arc and smoke and it fried the modem, saving my face.

The short answer, is that you don't even have the code (minimum) protection. You need at least an auxiliary ground rod to be code compliant. The CAT5 cables require secondary protectors at each end to be code compliant. (Easier to run the fiber with fiber transceivers, IMHO.) Once you have basic code compliance; only then you may want to think about adding other protection such as a 'whole-home' TVSS, etc.

When lighting strikes nearby it creates a ground potential rise, which is a large voltage rise in the earth and anything connected to it. Best bet is to have good grounding. This will reduce voltage potential differences between wires, which causes insulation and equipment failures.

JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5
I was hoping you would weigh in here

So I do need an additional rod on the main service entrance. Does the detached shed need a rod (or two?) as well? Right now it does not but is fed with 4-wire cable and neutrals/grounds are properly isolated in the panel as they should be for a sub panel.

I'm actually leaning towards going the fiber route honestly and getting rid of the Cat 5 cables to the shed (one of them hasn't worked since I pulled it in, may have damaged it). I'm searching Google now for the GBICs and cable I need and it's coming up cheaper than an additional building entrance protector so it's really a no-brainer.


mackey
Premium
join:2007-08-20
kudos:13
said by JoelC707:

Does the detached shed need a rod (or two?) as well?

Is it just a single branch circuit from the house or is there a subpanel in the shed? If there's a subpanel in it then there MUST be a ground rod at the shed which also connects back to the main panel with #6 wire minimum.

/M


mackey
Premium
join:2007-08-20
kudos:13
reply to JoelC707

Re: [Electrical] Re: Need help with surge/lightning damage

said by JoelC707:

Will have to look into that for sure as it would remove the issue completely.

Depends which issue we're talking about. It will not prevent stuff from getting blown; my equipment got fried with a 6' network cable...

/M


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
reply to mackey

Re: Need help with surge/lightning damage

said by mackey:

If there's a subpanel in it then there MUST be a ground rod at the shed which also connects back to the main panel with #6 wire minimum.

Not so everywhere. My electrician installed a ground rod in my new detached garage with a subpanel and the inspector made him remove the ground wire from it and run a 4th wire to the main ground and install a second ground rod tied to the original.


mackey
Premium
join:2007-08-20
kudos:13
Yes but how long ago was that? The current code requires it. 250.32

/M


Jack_in_VA
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join:2007-11-26
North, VA
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Reviews:
·Millenicom
The code required it then. That's why the electrician installed it. It doesn't matter what the code says. The inspector is the code here and people better not challenge it unless you don't want your work approved in the future.

Besides I don't have a problem with it at all. It's like 25 feet with 4 wire service to the subpanel. The ground rod is still there absent the conductor attached to it. I could hook up a ground wire to it if I wanted but it's fine the way it is.

JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5
reply to mackey
said by mackey:

Is it just a single branch circuit from the house or is there a subpanel in the shed?

It's an 80A fed sub panel with 3x #4 THHN and 1x #6 THHN in 1" conduit back to the panel on the utility pole. Total run is about 25-30 feet. If I need a rod there, can I use the existing #6 THHN to bond it back to the main panel or does it need a dedicated run?

JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5
reply to mackey

Re: [Electrical] Re: Need help with surge/lightning damage

said by mackey:

Depends which issue we're talking about. It will not prevent stuff from getting blown;

True, I'm talking about the issue of EM inducting into the long runs and needing the entrance protectors on each end of the circuit. If I switch to fiber, that issue goes away completely.


dark_star

join:2003-11-14
Louisville
kudos:1
reply to JoelC707

Re: [Electrical] Need help with surge/lightning damage

said by JoelC707:

Everything is connected to decent quality surge strips and/or battery backups.

You don't need a surge protector. You need a surge eliminator. Get a SurgeX (or as many as you need for high end TVs and primary computers).

Amazon occasionally puts them on sale for under $200 each. I know it sounds high priced compared to disposable MOV surge protectors, but the SurgeX is not a disposable device. Checking price... $183 today. Per camelcamelcamel.com (Amazon price watch site) it was $259 as recently as March 30.

»www.amazon.com/SurgeX-SA-82-Flat···DWPMRBA/

»www.surgex.com/products/flatpak-···ine.html

The SurgeX does not dump the surge to ground, which causes problems for grounded but unprotected equipment. SurgeX is literally a different class. A-1-1 Certification of surge elimination is a US Government standard, and no MOV protector will qualify.

Other brands similar to SurgeX are ZeroSurge and Brickwall. In my opinion, Brickwall is slightly inferior. Their surge elimination is fine, but the last time I checked, they do not offer the power filtering / RFI and sag cut out that SurgeX and ZeroSurge do.

Only problem with SurgeX is that they do not include connection for coax cable. I bought one of these for that. I'd say install it as close to your house ground rod as possible. It is a MOV supressor, so the ground wire must be connected to work.

»www.amazon.com/TII-Broadband-Cab···16AIYU6/

For that reason, I tend to unplug the coax when severe thunderstorms threaten.

said by JoelC707:

I assume I can tie it to the house ground and should not sink a specific ground rod for this (different potentials)?

Exactly right, per the NEC, for that exact reason.


Raphion

join:2000-10-14
Samsara
Reviews:
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reply to mackey

Re: [Electrical] Re: Need help with surge/lightning damage

said by mackey:

I just say if there's no noticeable delay between the flash and the BOOOOOOOOOOMMMMMMMM! it's way too close for comfort!

/M

Especially when I'm outside... on the roof. (true story) That'll wake you up.