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Jack_in_VA
Premium Member
join:2007-11-26
North, VA

Jack_in_VA to ThanksButNo

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to ThanksButNo

Re: [Electrical] Whole House Surge Protector Lost All Its Magic Smoke

said by ThanksButNo :

The second best way, which some of us are forced into by circumstance, is to electrically tie all the various grounds together with buried bare #6 copper running entirely outside of the structure. Needless, to say each entry point must have a ground round and lightening arrestor on each conductor.

Absolutely incorrect and dangerous. The only ground rod is at the service entrance to the structure. Multiple ground rods set up the chance of potential voltage differences which are very dangerous.

davidg
Good Bye My Friend
MVM
join:2002-06-15
00000

1 recommendation

davidg

MVM

multiple ground rods are perfectly fine IF they are properly bonded together. multiple rods that are not properly bonded together to form a system are dangerous and absolutely not acceptable. But what homeowner is going to go thru the thousands of extra bucks it costs to install a proper system?

ThanksButNo
@spcsdns.net

ThanksButNo

Anon

said by Jack_in_VA:

Absolutely incorrect and dangerous.

Gee, if you had READ the post you would have seen that is the whole point. Installers often come into the structure at a different entry point, which is undesirable, but happens. And it is equipment destroying catastrophe waiting to happen, not to mention the fire hazard. To protect the structure, that entry must be equipped with a proper ground rod and protector. That requires the grounds be bonded together, externally.
said by davidg:

But what homeowner is going to go thru the thousands of extra bucks it costs to install a proper system?

Thank you David.

But it doesn't necessarily cost thousands. A hundred or two will handle most properties with problem entrances, as long as the homeowner can do it himself. I have done several residential properties for myself and friends without issue. In each case, existing cable and/or telephone penetrations couldn't be relocated for various reasons. Installing the grounds and bonding them together in the manner I described worked as advertised, with no further loss of equipment equipment to lightning strikes in those case where it had been an existing problem.

lutful
... of ideas
Premium Member
join:2005-06-16
Ottawa, ON

lutful to davidg

Premium Member

to davidg
said by davidg:

multiple ground rods are perfectly fine IF they are properly bonded together.

Yes, for most homeowners, there should be a single ground rod for the main panel - installed by a competent electrician who minimizes the impedance rather than pursue zero ohm at DC.

Any home which has lightning rod(s) should have at least another ground rod located away from the utility ground rod. The two rods must be bonded for safety, ideally by running bare conductor below ground level.

P.S. Lots of relevant discussions and arguments: »Wireless ISP FAQ »Collection of Grounding Threads
lutful

lutful to ThanksButNo

Premium Member

to ThanksButNo
said by ThanksButNo :

said by Jack_in_VA:

Absolutely incorrect and dangerous.

Gee, if you had READ the post you would have seen that is the whole point. Installers often come into the structure at a different entry point, which is undesirable, but happens. And it is equipment destroying catastrophe waiting to happen, not to mention the fire hazard. To protect the structure, that entry must be equipped with a proper ground rod and protector. That requires the grounds be bonded together, externally.

What you explained is correct ... but each separate entry point does not need a separate ground rod, it is OK to make a robust low impedance bond to the ground ring which has sufficient number of properly spaced ground rods.

I once annotated 2009 FAA outdoor structure standard which has very elaborate grounding requirement: »/speak ··· pbGRvdXQ

Another thread you may find interesting - probably you are already familiar with the Motorola document: »[Tech Ops] Motorola R56 Document

of course such methods are overkill for typical homeowners - they just need a single ground rod which is properly installed.

Jack_in_VA
Premium Member
join:2007-11-26
North, VA

Jack_in_VA

Premium Member

said by lutful:

of course such methods are overkill for typical homeowners - they just need a single ground rod which is properly installed.

Exactly, for homes nothing else is needed.

LittleBill
join:2013-05-24

LittleBill

Member

this actually not true anymore, if a grounding test is not performed to indicate the ohm value is low enough, 2 ground rods with i believe 6 feet of separation must be run into the ground with a single unbroken ground wire back to the panel,

this is of course if the water line is not bonded

Jack_in_VA
Premium Member
join:2007-11-26
North, VA

Jack_in_VA

Premium Member

said by LittleBill:

this actually not true anymore, if a grounding test is not performed to indicate the ohm value is low enough, 2 ground rods with i believe 6 feet of separation must be run into the ground with a single unbroken ground wire back to the panel,

this is of course if the water line is not bonded

This is still considered a single ground point. My meter base is grounded to one and service panel mounted beside it is grounded to the other one. Two #6 bare copper ties them together.

OldCableGuy2
@communications.net

OldCableGuy2 to JoelC707

Anon

to JoelC707
The cable TV ground block IS NOT A LIGHTING ARRESTOR

It is designed to help tie the ground of the cable system to the rest of the electrical system ground so voltage differential doesn't exist.

It does not provide any protection from lightning strikes.

Several manufacturers make lightning arrestors for RG6 lines, I use these on every single TV antenna install I perform, but I don't know if they pass return path to know if they'd be useful in CATV or not. I have not installed CATV for 11 years now.
LittleBill
join:2013-05-24

LittleBill to Jack_in_VA

Member

to Jack_in_VA
in pa im told that is wrong. the line can't be broken between the 2 rods. Don't shoot me, just what i have been told

Jack_in_VA
Premium Member
join:2007-11-26
North, VA

Jack_in_VA

Premium Member

said by LittleBill:

in pa im told that is wrong. the line can't be broken between the 2 rods. Don't shoot me, just what i have been told

One ground wire comes from the meter base down to the first rod the other from the service panel down to the second rod. Given the two are effectively tied together as one rod nothing is broken.

Installed exactly as the local building inspector dictated to my electrician.

garys_2k
Premium Member
join:2004-05-07
Farmington, MI

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1 recommendation

garys_2k

Premium Member

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Autopsy Pictures

So I pulled the board out of the thing and washed it off a bit. No luck seeing the back of the board to work out a schematic, it's potted in what feels like silicone caulk. The top side, though, showed the hit.

It looks like there are five "banks" of paralleled MOVs, I guess one bank each between hot and ground (2), hot and neutral (2 more), and hot to hot. Four of the banks were packed in with each other, and a thermal fuse, with some heat shrink tubing (I cut it away here, it's obvious in the original picture). I guess the thermal fuse opens when the MOVs get too hot, likely in non-terminal situations where it would just disconnect the bank and turn off the LED.

One of the MOVs fell out when I turned the board over, note the difference between the first and second picture. That one had had its leads vaporized and had started to split open. The thermal fuse for that bank also had its lead vaporized, likely from the arc popping out of the one that disconnected itself. Looking closer, it's hard to see, but another MOV, the one just to the left of the left LED, is also damaged.

It looks like those two banks took the hit, all of them except the one on the far left are pretty significantly blackened.

Nasty spike! Glad it was there to catch it.

Edit: Maybe instead of hot to hot, the fifth bank of MOVs goes from neutral to hot. Seems more likely.
JoelC707
Premium Member
join:2002-07-09
Lanett, AL

JoelC707 to ThanksButNo

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to ThanksButNo
said by ThanksButNo :

Where does the Charter coax come in relative to the power service entrance? Unless it is in the same location, it needs its own proper ground rod, which should be tied back to the main service ground using buried bare #6. It also needs a quality protector, of course. Even a few feet of physical separation can result in differential voltage on the grounds during a lightening strike, if the grounds aren't tied together properly. The strike doesn't even have to be very near.

It's in the same location. I do not have any other protection on the circuit though my UPS does have coax protection. I suppose I could route the incoming line through it before it hits the amplified splitter in the house.

exocet_cm
Writing
Premium Member
join:2003-03-23
Brooklyn, NY

exocet_cm to Automate

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to Automate
said by Automate:

Also remember that lightning strikes don't always come in on the power lines. Cable and phone lines as well as a local antenna are other paths into your home. Protection at each utilization device can help with this.

Any recommended devices for use on coaxial lines? I have large UPS's on all of my servers and networking equipment but the cable line is straight into the cable modem.
JoelC707
Premium Member
join:2002-07-09
Lanett, AL

JoelC707

Premium Member

My APC BR1300LCD on my desktop has coax line protection. The thing to make sure is what frequencies does the device pass. Some older devices dropped the lower (return) frequencies and you'd never get an upstream lock. You also need to know how much loss the device introduces to the signal and make sure you have enough to still maintain positive connection. Sadly, the tech specs I see on APC's site for my UPS don't list any of these so I'll have to just try it and see what happens.

exocet_cm
Writing
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join:2003-03-23
Brooklyn, NY

exocet_cm

Premium Member

said by JoelC707:

My APC BR1300LCD on my desktop has coax line protection. The thing to make sure is what frequencies does the device pass. Some older devices dropped the lower (return) frequencies and you'd never get an upstream lock. You also need to know how much loss the device introduces to the signal and make sure you have enough to still maintain positive connection. Sadly, the tech specs I see on APC's site for my UPS don't list any of these so I'll have to just try it and see what happens.

All of mine are Tripp Lites with no coaxial in/out so I'll need a dedicated device just for this purpose.
JoelC707
Premium Member
join:2002-07-09
Lanett, AL

JoelC707

Premium Member

Yeah, I haven't seen many newer devices that have these. I have a Belkin (I think) surge protector floating around somewhere that has coax ports on it as well but the same would apply to it as well. APC lists it as "coax video protection" and if all you have it on is a cable box that is probably fine as they don't usually use the lower frequencies (though with SDV and all the other changes taking place even that's not guaranteed anymore).

If anyone has any recommendations I'm all ears as well (and will still try out my APC UPS when I get the chance to report for anyone who has a similar unit).
iknow_t
join:2012-05-03

iknow_t to garys_2k

Member

to garys_2k
said by garys_2k:

Autopsy Pictures

So I pulled the board out of the thing and washed it off a bit. No luck seeing the back of the board to work out a schematic, it's potted in what feels like silicone caulk. The top side, though, showed the hit.

use a screwdriver like a wood chisel, it'll come off. the better way is to heat the backside of the board, (oven at 200F, or heat gun) and then take it outside, and spray gumout carburetor cleaner on it. that breaks down the silicone, and it comes off in chunks with a screwdriver..

John Galt6
Forward, March
Premium Member
join:2004-09-30
Happy Camp

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John Galt6 to exocet_cm

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to exocet_cm
said by exocet_cm:

Any recommended devices for use on coaxial lines?

»www.l-com.com/surge-prot ··· otectors

»www.l-com.com/surge-prot ··· rotector

»www.alphadeltacom.com/pd ··· 0F-2.pdf

»www.citel2cp.com/pdf/P8A ··· 083A.pdf
tkdslr
join:2004-04-24
Pompano Beach, FL

tkdslr

Member

I just use a standard Grounding block under the eve where coax leaves the building, and then bound that insulated ground wire (min 12 gauge) to the main Grounding rod.

Besides common grounding point, I've got 70 feet of 1" copper water pipe with a doubled up grounding rods.

Multiple layers of surge suppressors.. starting with a GE THQLSURGE protector mounted in a 100 amp GE sub-panel next to main panel. And over 1/2 dozen distributed plug in surge suppressors inside the house. Along with a number of 4 or 5 GFI's.. (Each GFI has MOV surge suppression, same goes for uWave ovens).

But all those layers of protection can be bypassed one just bone headed move. (I plug'd in battery chargers for a docked sailboat behind my house via extension cord into one of my exterior GFI outlet's, not directly connected to main breaker box, nor the 60amp shore power box on the dock.. Within a year I paid the price.

A Lightning bolt struck the top of the sailboat mast. Vaporized 3ft antenna on top of the aluminum mast. Fried one of the battery chargers, timer switch, GFI outlet, zapped my 6 month old Win 7 Gateway laptop(I heard the snap just before the boom), and a Ethernet port on my 16 port D-link switch. Laptop, battery chargers, and GFI were all on the same circuit.

Lesson learned. Sail boat docked in canal NOW uses a flexible Solar panel to charge the batteries, no more wired connection to house.

My new Win 7 laptop lost only the GB ENET port, sd memory card slot and wifi. (All the PCI bus functions.) Used a powered external USB 2.0 port expander and various USB add ons to make up for the blown devices. One of these days I'll get around to opening up the laptop, who knows what I'll find.

Jack_in_VA
Premium Member
join:2007-11-26
North, VA

Jack_in_VA

Premium Member

Just a painful lesson in not being able to mitigate a lightning strike. Surge suppressors do a fair job on the incoming power surges but offer little to no lightning protection. Your sailboat mast made a good Arial for the lightning strike.