CATV Bonding and Grounding

[sjbowman]

Hello,

There was a lightning strike and a clatter of thunder the other day at my house. When it happened, it fried my cable box and the television the cable box was connected to, and flipped the breaker the cable box was on. This was the only breaker that flipped.

Went to Spectrum and got a new cable box. Connected the new cable box to another TV I had. Now that TV is fried.

Called an electrician out, and he wrote that he believes the CATV was not grounded/bonded properly. I've spent hours Googling this subject, and I'm trying to verify that what he said is in fact true. The electrician wrote, "Came out to possible lightning strike. Went through home @ problem location ===> no visible electrical problem. Inspected panel for signs of damage ===> none. *Customer did note TV's and cable box were damaged. Only circuit tripped during storm connected to cable box. Found that cable looks like it is not grounded properly. Connection is on lid = not a correct installation as entire lid is painted and separates from the housing."

Despite my best efforts to search and high-and-low for someone else who had this issue, I have not found any responses, and so I'm asking for a second opinion, and hoping someone can verify for me which NEC code this installation has violated. I'll need to contact the cable company, and I hope they'll reimburse for me the two TVs that got fried, and other ancillary expenses. I'd like to be well-prepared for that phone call, and for when the cable company guy comes out and tries to shovel me a line of b.s. so they don't have to reimburse me.

I greatly appreciate any insight and assistance.

Best Regards.

 

[infinity]

If you can snap some photos of the equipment and the connection that the electrician was referring to and possibly them here.

 

[Fred B]

Article 820 has specifications for bonding and grounding of CATV systems. Electrician likely aware of that section and it's requirements when making his findings, and I would not second guess his findings with info provided. Some CATV systems will use a signal booster that is plugged into the household electrical in addition to their periodic line boost at the poles. If booster damaged by lighting it could introduce voltage onto the CATV system and without bonding breaker may not trip. You can speak to the service tech about surge protection devices that can protect the coaxial as well as the power circuit at the utilization equipment. A good one would offer a warrenty to cover equipment if surge gets thru.

 

[sjbowman]

If you can snap some photos of the equipment and the connection that the electrician was referring to and possibly them here.

Hi infinity,

Thanks for the reply. I was trying to figure out how to attach a photo. I hope you can see these:

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Thanks again for any and all replies. Much appreciated.

 

[sjbowman]

Article 820 has specifications for bonding and grounding of CATV systems. Electrician likely aware of that section and it's requirements when making his findings, and I would not second guess his findings with info provided. Some CATV systems will use a signal booster that is plugged into the household electrical in addition to their periodic line boost at the poles. If booster damaged by lighting it could introduce voltage onto the CATV system and without bonding breaker may not trip. You can speak to the service tech about surge protection devices that can protect the coaxial as well as the power circuit at the utilization equipment. A good one would offer a warrenty to cover equipment if surge gets thru.

Thanks so much Fred B. for your reply!

 

[sjbowman]

If you can snap some photos of the equipment and the connection that the electrician was referring to and possibly them here.

Hi infinity,

Now I can see an "Attach files" button. I'm going to attach the photos now.

Thanks!

 

[hbiss]

When it happened, it fried my cable box and the television the cable box was connected to, and flipped the breaker the cable box was on. This was the only breaker that flipped.

Went to Spectrum and got a new cable box. Connected the new cable box to another TV I had. Now that TV is fried.

Well, It wouldn't be unusual for lightning to fry the cable box- even cause the breaker to trip. What I find unusual is that, after the fact, now it seems connecting another TV to a new cable box caused it to be damaged.

Other than a few pictures you offer no other information such as voltage readings at the receptacle and if there is any voltage between the incoming RG-6 connector and the cable box while disconnected from the box. You also provide no information as to how the TV is connected to the box. HDMI or what?

My impression is that the second TV was damaged by the same lightning strike and you didn't see it until you reconnected it to the new box. I base that on the breaker being tripped which would indicate that the surge got into your electrical system. I would expect to see other damage as well.

I see nothing wrong with the ground that the cable company provided. No, it's not strictly NEC complaint but it is how they do things.

You can't expect to be safe from all lightning activity no matter how you try.

-Hal

 

[sjbowman]

Well, It wouldn't be unusual for lightning to fry the cable box- even cause the breaker to trip. What I find unusual is that, after the fact, now it seems connecting another TV to a new cable box caused it to be damaged.

Other than a few pictures you offer no other information such as voltage readings at the receptacle and if there is any voltage between the incoming RG-6 connector and the cable box while disconnected from the box. You also provide no information as to how the TV is connected to the box. HDMI or what?

My impression is that the second TV was damaged by the same lightning strike and you didn't see it until you reconnected it to the new box. I base that on the breaker being tripped which would indicate that the surge got into your electrical system. I would expect to see other damage as well.

I see nothing wrong with the ground that the cable company provided. No, it's not strictly NEC complaint but it is how they do things.

You can't expect to be safe from all lightning activity no matter how you try.

-Hal

Hi Hal,

Thanks for your reply. The cable box and the TVs were connected by an HDMI cable. In addition, when the strike happened, the TV, cable box, digital clock, and small electric fireplace had all been plugged into a $99 Rocketfish surge protector, that I thought was supposed to sacrifice itself before it sacrificed the devices connected to it. In fact, the surge protector has a $600,000 connected device guarantee. The surge protector still works great, and only the cable box and TV got fried. The inexpensive digital clock and small fireplace were not the least bit affected. Per the electrician that came out, he explained this was because the jolt traveled through the CATV line, and never went through the surge protector. In addition, the second TV only got fried once we connected the cable box to it. Prior to that, we were using it just fine with an Amazon Fire Stick. It was only once I got the replacement cable box, and connected it to the TV, that the TV became fried. Sorry, as I meant to add that additional information earlier.

I truly appreciate your reply, and I sincerely apologize for the lack of information. I don't have a voltmeter handy to provide the readings you suggested. While I'm an electrical engineer, I work mostly in software development.

I just ordered a new TV from Best Buy, that my wife just picked up. I am not going to plug it into the cable box until the cable company comes out here and tells me what's what. When the electrician came out yesterday, he said that the voltage readings at all outlets were perfect.

Thanks again.

 

[hbiss]

Per the electrician that came out, he explained this was because the jolt traveled through the CATV line, and never went through the surge protector.

I just ordered a new TV from Best Buy, that my wife just picked up. I am not going to plug it into the cable box until the cable company comes out here

We get this kind of story every once and awhile and they never make sense. Then we never hear back from the OP about any kind of resolution.

If the "jolt" didn't go through the surge protector how did the breaker trip? It could be that it was actually doing it's job, that's why the breaker tripped.

About the only thing I could think of is that that most cable boxes don't have a 3-wire line cord and grounding plug. Do your TVs happen to have grounding plugs? If they did, there would be a path from the receptacle ground, through the TV, through the HDMI cable to the cable box which is connected by the RG6 shield to the cable on the pole (or UG pedestal). The ground on your meter enclosure should mitigate differences in potential between your receptacle (electrical) ground and the outside plant by tying them both together where the cable enters the house. But even in a perfect world things happen and lightning is unpredictable.

That said, I would ask the cable guy to connect everything up for you, that way it's on them.

-Hal

 

[sjbowman]

We get this kind of story every once and awhile and they never make sense. Then we never hear back from the OP about any kind of resolution.

If the "jolt" didn't go through the surge protector how did the breaker trip? It could be that it was actually doing it's job, that's why the breaker tripped.

About the only thing I could think of is that that most cable boxes don't have a 3-wire line cord and grounding plug. Do your TVs happen to have grounding plugs? If they did, there would be a path from the receptacle ground, through the TV, through the HDMI cable to the cable box which is connected by the RG6 shield to the cable on the pole (or UG pedestal). The ground on your meter enclosure should mitigate differences in potential between your receptacle (electrical) ground and the outside plant by tying them both together where the cable enters the house. But even in a perfect world things happen and lightning is unpredictable.

That said, I would ask the cable guy to connect everything up for you, that way it's on them.

-Hal

Hi Hal,

If the surge protector did its job, then why did my cable box and TV get fried? Not sure I understand why anyone would spend $99 on a surge protector if it doesn't actually protect devices from surges. I ought to be able to get reimbursed by Rocketfish per their $600,000 lifetime guarantee. They will want the surge protector back, and apparently they can test it and find out if a surge went through it. But, I suppose I still don't know why the cheap digital clock and electric fireplace also plugged in didn't get fried, but the high-end TV did? Also, it was always my understanding the surge protector would get fried if it did its job, and protect the devices connected to it. Not the other way around.... trip the breaker, fry the devices, keep the protector in tact.

That's why I posted on here though, to get expert opinions such as yours in order to have the most information possible for when the technician does come out. I assure you I will continue to update this thread with developments as they arise. Spectrum still hasn't called me back, despite the woman on the phone telling me that since she put the ticket in as a safety issue, I should get a call back within the hour. That was about 5 hours ago.

Thanks Hal for your input. I greatly appreciate it sir.

 

[hbiss]

If the surge protector did its job, then why did my cable box and TV get fried?

Probably because the clamp voltage was more than what the cable box and TV could withstand. No way to know or for whoever designed the protector to know what will be plugged into it and what it can handle. Really, surge protection devices are designed to protect against power line surges, not the devastation of lightning.

I ought to be able to get reimbursed by Rocketfish per their $600,000 lifetime guarantee.

Don't hold your breath.

Also, it was always my understanding the surge protector would get fried if it did its job, and protect the devices connected to it.

Not necessarily. I just got done saying in another thread, I have extensive experience in the telecom field and lots of experience with protectors on POTS lines. Sometimes they will be blown across the room yet the equipment connected after them will be undamaged, sometimes the fuses will just be blown, sometimes nothing will happen to the protector yet the equipment will be destroyed. All exactly the same protectors but all different locations and lightning storms.

I have had ethernet and voice system ports damaged from the EMP induced on the wiring within the building by a nearby lightning strike.

My best advice is to understand that lightning is unpredictable and sometimes there is no defense. You can spend thousands on protection schemes that may or may not do anything. It's a crap shoot.

If you really want to be safe, go around and disconnect everything when you see a storm approaching.

-Hal

 

[Fred B]

Hi Hal,

Thanks for your reply. The cable box and the TVs were connected by an HDMI cable. In addition, when the strike happened, the TV, cable box, digital clock, and small electric fireplace had all been plugged into a $99 Rocketfish surge protector, that I thought was supposed to sacrifice itself before it sacrificed the devices connected to it. In fact, the surge protector has a $600,000 connected device guarantee. The surge protector still works great, and only the cable box and TV got fried. The inexpensive digital clock and small fireplace were not the least bit affected. Per the electrician that came out, he explained this was because the jolt traveled through the CATV line, and never went through the surge protector. In addition, the second TV only got fried once we connected the cable box to it. Prior to that, we were using it just fine with an Amazon Fire Stick. It was only once I got the replacement cable box, and connected it to the TV, that the TV became fried. Sorry, as I meant to add that additional information earlier.

I truly appreciate your reply, and I sincerely apologize for the lack of information. I don't have a voltmeter handy to provide the readings you suggested. While I'm an electrical engineer, I work mostly in software development.

I just ordered a new TV from Best Buy, that my wife just picked up. I am not going to plug it into the cable box until the cable company comes out here and tells me what's what. When the electrician came out yesterday, he said that the voltage readings at all outlets were perfect.

Thanks again.

If the surge generated through the coax and the coax wasn't run through the surge protection it wouldn't have helped. Also, Spectrum sometimes utilizes a signal booster that is plugged in to a power source, if that is compromised and remains energized the coax will remained energized as well. Then anything plugged in will get shorted.
I believe I've seen on a video presentation by Mike that said that a surge will always take out the most expensive item in preference to the least expensive (or something to that effect).

 

[hbiss]

If the surge generated through the coax and the coax wasn't run through the surge protection it wouldn't have helped.

At his point nobody knows exactly what path or paths the lightning surge took and I doubt there is any real way to know as is usual in these cases. The unusual issue is the apparent continuing problem with the second set and new cable box. If it were me I would check for stray voltage from the coax to the receptacle ground and if nothing is found I would call it good. I can't see anything else that would cause that situation.

Also, Spectrum sometimes utilizes a signal booster that is plugged in to a power source, if that is compromised and remains energized the coax will remained energized as well. Then anything plugged in will get shorted.

You mentioned that before. That little "signal booster" (if used) doesn't put power on the coax and even if it somehow did, it's powered by a little class 2 12 volt wall wart which isn't going to do much of anything.

-Hal

 

[retirede]

Forensic analysis of power surge damage is difficult enough when you are on site. It’s almost impossible with an online discussion!

 

[grich]

...I have had ethernet and voice system ports damaged from the EMP induced on the wiring within the building by a nearby lightning strike...

I've dealt with several EMP incidents just like this. Not a single power supply was lost. Lots of dead phones, Ethernet switches, and NICs. The local engineer for a big radio station group lamented not building his studios with EMT for his data runs after getting slammed twice. He's got a 100' monopole outside just begging to be struck.

At one site, the CATV was not bonded, even though the main grounding bar should have poked the installer's eye out when he set his first splitter. Getting that bonded ended trouble there.

 

[jim dungar]

When the electrician came out yesterday, he said that the voltage readings at all outlets were perfect.

Did he check the CATV outlets also?

 

[hbiss]

Did he check the CATV outlets also?

He's an electrician. How would he do that? I've already talked about checking for voltage from the cable (connected to the cable "outlets") to the 120V receptacle ground. That's about all he could do, and really all that matters.

-Hal

 

[jim dungar]

I've already talked about checking for voltage from the cable (connected to the cable "outlets") to the 120V receptacle ground.

I simply asked if this was actually done. I took the OP's comments that the electrician checked the 'outlets' as being related to the 120V surge device operation and breaker tripping only.

 

[sjbowman]

I simply asked if this was actually done. I took the OP's comments that the electrician checked the 'outlets' as being related to the 120V surge device operation and breaker tripping only.

Hi Jim, Fred, Hal, and others:

I wasn't getting e-mail notifications of additional posts, so just reading these now. The Spectrum technician is on his way to my house as I type this. Thanks for the additional suggestions, and will post further updates shortly regarding this.

I really appreciate the expertise from all of you! It has been very helpful. Thanks again!