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Electrical shock installing cable splitter

post #1 of 23
1/5/12 at 1:47pm
Thread Starter 
Hi, I came across an interesting problem and was hoping for some help. Sorry for the length. To summarize, the issue is that when trying to replace a splitter I can feel a mild shock on one length of cabling and touching the splitter.

About a week ago AT&T Uverse stopped working on my Mitsubishi 60638. The Uverse box could not connect to anything. I tried rebooting, etc., but found the real problem. The cable from the wall plate to the surge protector was bad(a red plastic ring at the end looked melted). Also the wall plate itself looked like it had been hit with a surge(the plastic in the middle looked a little melted and the end was a little black).

This was the only sign of a problem in the house. The other tv's and surge protectors seemed to be working fine.

I went out and bought a new surge protector and wall plate(I had an extra cable laying around). After replacing the wall plate I was able to plug the cable from the Uverse box directly into the plate and everything worked fine. I did not immediately plug the cable into the surge protector.

While going through this I realized that the Uverse installer had kindly given me a 4 way splitter instead of the two way one I needed. I was hoping to improve my signal strength and tried to replace the splitter. The input was fine and the first output was fine, but the second output which leads to the Mitsubishi box with the problem mentioned above, gave me a mild shock.

After much checking on things, it only seems to occur when the tv is on, or is in the lengthy process of shutting down. Even with the Uverse box unplugged it seems to get a current through the HDMI connection that then continues through the cable to where I am connecting the splitter. When I plugged the cable into the surge protector that issue seems to have gone away.

My questions are - am I damaging my other components hooked up through HDMI? Is this something that I need to get fixed on my tv? Is this a Uverse issue, HDMI issue, Mitsubishi issue, or an issue with wiring at my house?

Any suggestions or ideas are greatly appreciated.
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post #2 of 23
1/5/12 at 1:49pm
You have a ground fault somewhere in your house wiring or one of your components. Have a LICENSED electrician check this out.

This is dangerous!

Also don't use a 4way splitter when you only need a two way. It causes more signal loss. If you must use a larger splitter, then the unused ports must have a 75ohm terminator installed otherwise you get reflections which can cause digital hits.
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post #3 of 23
1/5/12 at 2:19pm
If you have U-Verse and using coax for the runs from the RG to the set top & dvr, you can not have it going through the surge protectors, and yes, there can be a small voltage present on the coax network, just like ethernet networks can have a slight minuscule return voltage on certain pairs.

I tell people that if they can, ditch the coax HPNA network for U-Verse and go with Ethernet, due to too many people have problems with dropouts, etc if you have more than two boxes.

Also, HDMI, USB, SATA all have some type of small voltage present, USB especially. As for the splitter, a normal off the shelf splitter will not work with the HPNA setup.
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post #4 of 23
1/5/12 at 2:37pm
Quote:
Originally Posted by gregzoll View Post

If you have U-Verse and using coax for the runs from the RG to the set top & dvr, you can not have it going through the surge protectors, and yes, there can be a small voltage present on the coax network, just like ethernet networks can have a slight minuscule return voltage on certain pairs.

I tell people that if they can, ditch the coax HPNA network for U-Verse and go with Ethernet, due to too many people have problems with dropouts, etc if you have more than two boxes.

Also, HDMI, USB, SATA all have some type of small voltage present, USB especially. As for the splitter, a normal off the shelf splitter will not work with the HPNA setup.

If you can feel a shock with dry hands, that's well over 10ma of current. This is not normal. What ever is causing that leakage could deteriorate further. The mention of a melted insulating ring makes this highly suspicious. The coax cable must be grounded at the service entrance point by code. It's the same for CATV or Phone service. There must be a grounding bond at the electrical service. Voltage on the coax shield in a residential setting is often a result of this ground connection being missed or ignored by indifferent installers.

A professional needs to check this out further.
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post #5 of 23
1/5/12 at 2:47pm
Thread Starter 
Thanks for the advice! I will track down an electrician to take a look at things. It was definitely weird since I have two similar setups, but only get this out of one cable line.

The way the Uverse tech installed it was the cable coming into the house into a diplexer and the HPNA line going into the four way splitter. I had not realized that was the case and I was hoping that by changing it out to a two way splitter I would get a better signal.

I would love to switch the cabling out for Ethernet, but running the extra cabling is not something I have wanted to tackle or pay to be done.
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post #6 of 23
1/5/12 at 5:01pm
When I had a temporary outdoor antenna connected to many pieces of equipment with a 4-way splitter to make a comparison of tuner sensitivity, I felt a mild shock. The coax was not grounded, but when I grounded it, there was no more shock.
www.avsforum.com/avs-vb/showthread.php?p=18772087#post18772087

Every piece of AC connected equipment has a small harmless normal leakage current. When many pieces are connected together, the leakage currents add. You must find out which piece of equipment is causing the shock hazard. It could only be the normal leakage current that you feel, but if you see signs of damage on your cable the leakage current could be lethal. After having three close calls, I bought a Simpson 229 leakage current tester and was able to measure the current.
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post #7 of 23
1/5/12 at 5:31pm
Quote:
Originally Posted by Glimmie View Post

If you can feel a shock with dry hands, that's well over 10ma of current. This is not normal. What ever is causing that leakage could deteriorate further. The mention of a melted insulating ring makes this highly suspicious. The coax cable must be grounded at the service entrance point by code. It's the same for CATV or Phone service. There must be a grounding bond at the electrical service. Voltage on the coax shield in a residential setting is often a result of this ground connection being missed or ignored by indifferent installers.

A professional needs to check this out further.

Thing is, the Coax for the HPNA for U-Verse is not and should not be grounded, since it is a LAN. Now, if it goes from a iNID, or a balun in the NID, and someone put a ground block on it and grounded to the house ground, yes there could be something very wrong with the electrical system in that place.

And actually you can sense current as low as 1ma, some people even lower, it is just the nature of the human body. Especially in Winter time when the air is drier in most homes.
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post #8 of 23
1/5/12 at 5:35pm
Quote:
Originally Posted by mree449 View Post

Thanks for the advice! I will track down an electrician to take a look at things. It was definitely weird since I have two similar setups, but only get this out of one cable line.

The way the Uverse tech installed it was the cable coming into the house into a diplexer and the HPNA line going into the four way splitter. I had not realized that was the case and I was hoping that by changing it out to a two way splitter I would get a better signal.

I would love to switch the cabling out for Ethernet, but running the extra cabling is not something I have wanted to tackle or pay to be done.

Go over to the utalk.att.com forum and post a PM to Username David, or over at dslreports, post this stuff in the ATT direct forum.

Make sure that you give your account number, contact number, person in charge of the account, pictures are also very helpful, but do not post macro zoom. DSLreports will resize the photo over there, vs. the att forum will not.

Now, if you want you can post the same here and I can take a look, since I have been dealing with telcom stuff since my Navy days in the 80's, and grew up with my dad working for the telephone company, so this stuff is in my blood inherently. I can tell you what is what.

Another thing, go and download the Uverse Realtime tool from uverserealtime.com and you can post the screen shots from the tabs on the direct forum, since it will give some helpful info, especially on the first tab of the program.

Also, you can not mix two different systems on the HPNA network, or you can burn out the RG or iNID.
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post #9 of 23
1/5/12 at 6:55pm
Quote:
Originally Posted by gregzoll View Post

Thing is, the Coax for the HPNA for U-Verse is not and should not be grounded, since it is a LAN. Now, if it goes from a iNID, or a balun in the NID, and someone put a ground block on it and grounded to the house ground, yes there could be something very wrong with the electrical system in that place.

And actually you can sense current as low as 1ma, some people even lower, it is just the nature of the human body. Especially in Winter time when the air is drier in most homes.

So is the coax transformer coupled to the users end?
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post #10 of 23
1/5/12 at 7:22pm
Quote:
Originally Posted by Glimmie View Post

So is the coax transformer coupled to the users end?

There should be nothing on the HPNA network. This is a closed loop system like ethernet. It is not catv. You can not put anything on it but the coax & HPNA splitter. You cannot incorporate catv, fios, antenna, third party Internet into that system, since it is only meant for carrying the multicast for the settops and dvr for UVerse.

Me thinks that the OP is trying to do something with their HPNA network, that they should not be, and this is why they always end up wondering why things do not work correctly after the installer has left, when things actually worked correctly.

I wired my home up with Cat-5e for my U-verse install, along with one computer, Blu-Ray and xbox-360 that also uses the LAN. Other devices use wifi, with the 3800hgv-b doing both. I have never had any problems with my UVerse install. Only time I did, was when I tried to do a hybrid setup, by using one run of coax to the set top in our bedroom, so that I could use the cat-5e in there for the roku, but that failed, so the roku is wifi, and the set top cat-5e. Never had a problem, no voltages present on the system.
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post #11 of 23
1/6/12 at 7:30am
Thread Starter 
I don't think that I am doing anything I shouldn't be with this. The only thing I have changed from when the installer came about three years ago is to try and change out the four way splitter for a two way.

My understanding, and it could definitely be wrong, is the diplexer is splitting the signal in two. One of those cables (labeled VDSL on the diplexer) goes directly to the gateway which has a cat5 connection to the DVR. The other line out goes (labeled HPNA/TVRF) directly into the splitter. Those two cable lines then run two the two dummy boxes (non DVR, but can playback the DVR's shows) connected to two other tvs.

The diplexer and splitter are both side by side and "floating" in the drop down ceiling and are not grounded or attached to anything but the cables. That is the setup that the Uverse installer put in. If that doesn't sound optimal, please let me know what I can do, or have AT&T come back and change, to make it better(outside of running cat 5).

If there is a ground fault that is leaking through the cable back to the splitter, would that cause some picture quality problems, like screen freezing and pixelation? I was having some of those problems, but thought that replacing the splitter would fix that.

I was going to contact Uverse support, but since the only time I can feel the electricity is when the tv is turned on, even with the uverse box unplugged and the only connection is from the tv to the uverse box through hdmi, I thought the probelm was more on my end and they would be unable to help, but I will try out the other forum as well.

Thanks for all of your help and advice, I really appreciate it. I can change out a splitter or a wall plate, but much past that is over my head.
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post #12 of 23
1/6/12 at 8:21am
Going back to what I stated, the HPNA can not go through the surge protector. There is no reason to do so, because it is considered a isolated closed circuit network. Uverse is not catv, and does not need to be protected for the LAN through the surge.

Most likely you got hit with a spike, and in turn possibly not only fried the dvr/stb, but even the RG. If you can not get a quick ticket to have a tech come, contact David, a ATT employee at http://www.uverseusers.com/index.php...id=36&id=david I dealt with him a couple of times, and when I had old school DSL he did professional and top notch job, just like my father would do, when stuff needed escalated and Cust. service dropped the ball.

I no longer go on the utalk.att.com forum, due to too many indifferences in the mod's not taking care of the one hit posters that would troll over there. Let's just say that when I tried to spell it out and get people to understand, which you are from what I can tell looking to how to solve this without getting anymore frustrated than you already are. But it is just that some over there disagreed with my opinion in solving the trolls hitting the revolving door, etc.

Keep me updated on this. I would wish that they would start a Uverse sub-forum on here since overall I find some stuff relevant on here, and when it is technical type stuff, especially networking, it is more up my alley.
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post #13 of 23
1/6/12 at 9:36am
Quote:


And actually you can sense current as low as 1ma, some people even lower, it is just the nature of the human body. Especially in Winter time when the air is drier in most homes.

You're confusing static discharge with leakage currents.
The bodys ability to 'sense' current, as you put it, would be less when dry.
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post #14 of 23
1/6/12 at 11:35am
Quote:
Originally Posted by gregzoll View Post

There should be nothing on the HPNA network. This is a closed loop system like ethernet. It is not catv. You can not put anything on it but the coax & HPNA splitter. You cannot incorporate catv, fios, antenna, third party Internet into that system, since it is only meant for carrying the multicast for the settops and dvr for UVerse.

Ok but is the coax feed for Universe grounded at the home's service entrance point? I would be surprised if its not. Even POTS is grounded at this point. Any outside service except fiber cable must be grounded to the house central ground point.

This has nothing to do with the nature of the service. It has to do with the coax shield contacting a live wire. Unless grounded it can place a dangerous voltage potential on the coax shield. This is an NEC requirement and AFAIK, no utility is exempt except of course optical fiber as in FIOS.
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post #15 of 23
1/6/12 at 12:21pm
No it shouldn't be grounded, due to the coax is a LAN hookup. Only thing that should be grounded, is out at the NID, the incoming telco should be grounded to the building's earth ground.

There are two ways to hook up the IPTV settops and DVR to the RG. One is Coax on HPNA, the ither is Ethernet. Now, with the newer boxs, they use a Wireless-N A/P to send the signal, so no cord from the RG to the set-top.

Think of it like hooking up computers to a router, same concept.
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post #16 of 23
1/6/12 at 1:21pm
Quote:
Originally Posted by gregzoll View Post

No it shouldn't be grounded, due to the coax is a LAN hookup. Only thing that should be grounded, is out at the NID, the incoming telco should be grounded to the building's earth ground.

There are two ways to hook up the IPTV settops and DVR to the RG. One is Coax on HPNA, the ither is Ethernet. Now, with the newer boxs, they use a Wireless-N A/P to send the signal, so no cord from the RG to the set-top.

Think of it like hooking up computers to a router, same concept.

Ok, but the coax is probably grounded within the NID where the incomming telco line is grounded.
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post #17 of 23
1/6/12 at 2:38pm
No it is not. The coax for the hpna is treated the same as if you were hooking up ethernet to it. The RG does not get grounded. Now the iNid, which is outside has a bonding ground to the structure's earth ground, from the incoming telco drop.

I will see if I can dig up some pictures of this, or upload how mine is set up, which is via ethernet only.
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post #18 of 23
1/6/12 at 3:04pm
Quote:
Originally Posted by gregzoll View Post

No it is not. The coax for the hpna is treated the same as if you were hooking up ethernet to it. The RG does not get grounded. Now the iNid, which is outside has a bonding ground to the structure's earth ground, from the incoming telco drop.

I will see if I can dig up some pictures of this, or upload how mine is set up, which is via ethernet only.

So then it must be transformer coupled internally? Whatever, I'm not really familiar with this specific technology. I'm sure it's listed by UL or some other certified safety agency.

But I still think the OP should have his system checked out like you suggested as well.
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post #19 of 23
1/6/12 at 3:52pm
Quote:
Originally Posted by Glimmie View Post

So then it must be transformer coupled internally? Whatever, I'm not really familiar with this specific technology. I'm sure it's listed by UL or some other certified safety agency.

But I still think the OP should have his system checked out like you suggested as well.

There is no transformer, there is no coupled technology. When you hook up between the RG to the settop or dvr, it is just that, it is a jumper. If you have more than one set top, along with a dvr, then you would have a splitter to split the HPNA to the three IPTV devices that connect to the network.

No where does it exit the structure, unless there is a iNID, and even then it is considered a isolated type connection, because it does not hit anywhere outside, other than the telco line that connects to either the NID or iNID.

What the OP did is hook up his UVerse HPNA network as if he thought that it worked like catv and in turn fried the leased equipment that att is letting his use to enjoy their service. Attached is a link to the userguide for the RG to explain it better. http://www.scribd.com/doc/3849281/38...uter-Userguide

Here are the user guides from att: http://www.att.com/esupport/uverse-user-guides/
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post #20 of 23
1/6/12 at 7:46pm
Thread Starter 
I assume I am the "OP". Not to be argumentative, but once again, all I did was try to change the 4 way splitter used by the Uverse technician, to a two way splitter and then felt a mild shock. I do not think any of their leased equipment, that I have had for about three years, is fried.

My main concern is finding out where the extra power is coming from and if it is feeding back through the tv to the Uverse box and through the cable or if it is a ground fault in my house. Thankfully I did have my cable plugged into the surge protector and then into the Uverse box, or else the leased Uverse box might have been "fried" along with my tv. All of this has been a working system for a couple of years, although I never felt the cable before to feel if any current was going through it.
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post #21 of 23
1/6/12 at 8:19pm
Quote:
Originally Posted by mree449 View Post

I assume I am the "OP". Not to be argumentative, but once again, all I did was try to change the 4 way splitter used by the Uverse technician, to a two way splitter and then felt a mild shock. I do not think any of their leased equipment, that I have had for about three years, is fried.

My main concern is finding out where the extra power is coming from and if it is feeding back through the tv to the Uverse box and through the cable or if it is a ground fault in my house. Thankfully I did have my cable plugged into the surge protector and then into the Uverse box, or else the leased Uverse box might have been "fried" along with my tv. All of this has been a working system for a couple of years, although I never felt the cable before to feel if any current was going through it.

The problem is, you are running the HPNA network, which is the coax through a surge protector, which it does not need to be. Again, this is not catv, it is IPTV, which is a whole different technology. On top of that, the HPNA works like your LAN that your home computer, xbox-360 or PS3 would connect to the router, to get you to the outside world.

Do yourself a favor, remove any cables from the surge protector, put back on the 4-way splitter, and connect everything back up as it should between the RG & set-tops & DVr. If it still does not work, put in a trouble ticket at either link info that I gave earlier on. There is not much more that I can say or stress, that doing what you did, is not the way that you hook up the IPTV boxes for U-verse, nor is it the correct way, because you tried to do something that you thought was correct, even though it wasn't, due to you did not understand the technology.

I am not getting pissed at what you did, but I can only rehash this over and over so much, before it sounds repetitious and tiresome of stating.
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post #22 of 23
1/6/12 at 8:30pm
Also to add, if you did have a surge feeding back through the surge protector, which can happen, if you took that coax and split down the sheath, you would find pinholes and burnt spots in the die-electric sheath inside. Best bet is to replace the coax, and while you are at it, pull either Cat-5e or Cat-6 (min. two runs) to each location, and then connect your U-Verse boxes that way, vs using the Coax HPNA.

Even better, when you contact tech support, ask for them to send out the new Wireless-N set top for a self-install, and get a RMA to return the bad equipment or set up a trouble ticket to have a tech bring the newer 3801 RG if you do not have a iNID.

You have not posted pic's of the problem coax, nor equipment so it is hard to guess what equipment you currently have for Uverse.
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post #23 of 23
1/9/12 at 7:06am
Thread Starter 
The Uverse tech came out last night and spent a good bit of time tracking down the issue, kind of. After much looking around and trying different things he determined that there is some electrical problem at the location where everything is plugged in. He was holding the voltmeter up to the end of the cable coming out of the Uverse box with the box not being connected to anything and was getting enough current to make the meter go off. Moving the Uverse box to different part of the basement and plugging it in and trying the same test showed nothing on the voltmeter. He said it was not a full ground fault or the readings would have been much higher.

I did ask both him and the phone support, and they both said the same thing - it can cause quality issues for some people, but if the quality is okay then there is no problem with using one.

I am working on getting an electrician scheduled now and that should take care of things. Thanks for all of the help and advice, I really appreciate it.
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