Burnt Cable!

speedymove · 13-11-2009, 10:20

Okay, where do I start? I live in the Southampton area and 2 evenings ago we suddenly noticed a drop in the voltage coming into our house, lights were dim, microwave not working etc.. The same was true for the neighbourhood. Of course this also affected my V+ box downstairs and also the other box virgin box upstairs. I was seeing the usual AP52 code on the V+ box which means no signal coming in.

Anyway, I phoned virgin support and they said there was a problem in the area and it will be sorted the next day. I also phoned the scottish and southern electric about the problem with power and they also said it would be fixed the next day.

The next morning the voltage was surging up and down between 190 volts and 230 volts and we smelt an awful burning smell coming from the bedroom where the upstairs box was. At the time I couldn't trace the source of the burning smell but needless to say I switched all the power off and called the emergency number.

To cut a long story short, the power was eventually fixed in the early hours of the next morning but the V+ box was still not working. I called virgin support again about an hour ago and they said it should all be working and an engineer is on his way to look at my setup. Anyway, in readiness for the visit of the engineer I looked again at the virgin box upstairs and to my utter horror I noticed that the coax cable going into this box had most of its insulation burnt and charred! Obviously now I know where the burning smell came from.

This has left me extremely concerned about the safety of the cable installation as a whole. What if I hadn't been here to switch of the power? We could have been asleep and it could have happened then. I am certainly going to get rid of the box upstairs as a result and I wonder now how I can make more people aware of this potential danger.

I would welcome any advice about this as I am really concerned about the safety of these Virgin cable boxes and where I go from here.

MovedGoalPosts · 13-11-2009, 11:33

If there was a fault with the mains power supply to the house - evidenced by your showing the vlotage was fluctuating widely, lights were dimming etc. then it is the mains wiring that will have been suspect. In turn that faulty mains wiring could have caused damage to other cabling which would not normally carry large current.

You do of course need virgin to check what has been damaged with their installation, including all cabling, modems and set top boxes. They should also check that the necessary isolators are in place.

But I would be pointing the real blame at the electricity supply. Was it a fault in the mains network? If so require the electric board to confirm your wiring has not been damaged and you'll probably be claiming against them for any appliances damaged or other costs you incurred.

speedymove · 13-11-2009, 11:52

Hi Rob, yes it was a fault with the electric supply to the whole neighbourhood and I will be taking the issue up with them. To be honest the finger of blame is not foremost in my mind, I just want everyone to know that potentially the coax cables to our boxes can burn. It was just lucky that we were awake and also in the house at the time. I also wonder whether the necessary isolators were in place for our install and I will ask the engineer when he gets here.

Quote:

Originally Posted by Rob

If there was a fault with the mains power supply to the house - evidenced by your showing the vlotage was fluctuating widely, lights were dimming etc. then it is the mains wiring that will have been suspect. In turn that faulty mains wiring could have caused damage to other cabling which would not normally carry large current.

You do of course need virgin to check what has been damaged with their installation, including all cabling, modems and set top boxes. They should also check that the necessary isolators are in place.

But I would be pointing the real blame at the electricity supply. Was it a fault in the mains network? If so require the electric board to confirm your wiring has not been damaged and you'll probably be claiming against them for any appliances damaged or other costs you incurred.

Kymmy · 13-11-2009, 13:10

If you were worried about cable burning due to a fault then you simply wouldn't have any mains powered electrical equipment in the house as component failure inducing a short can happen to any device..

One question which this does bring up is are VM cabinets protected with the correct type of circuit breakers

speedymove · 13-11-2009, 13:26

Hi Kymmy, true enough but the fact that every other piece of electrical equiptment in the house survived and showed no adverse affects from the power drop is cause for concern. Why is it that just the coax to the second box burned and nothing else.

Quote:

Originally Posted by Kymmy

If you were worried about cable burning due to a fault then you simply wouldn't have any mains powered electrical equipment in the house as component failure inducing a short can happen to any device..

One question which this does bring up is are VM cabinets protected with the correct type of circuit breakers

sollp · 13-11-2009, 13:26

Quote:

Originally Posted by speedymove

Okay, where do I start? I live in the Southampton area and 2 evenings ago we suddenly noticed a drop in the voltage coming into our house, lights were dim, microwave not working etc.. The same was true for the neighbourhood. Of course this also affected my V+ box downstairs and also the other box virgin box upstairs. I was seeing the usual AP52 code on the V+ box which means no signal coming in.

Anyway, I phoned virgin support and they said there was a problem in the area and it will be sorted the next day. I also phoned the scottish and southern electric about the problem with power and they also said it would be fixed the next day.

The next morning the voltage was surging up and down between 190 volts and 230 volts and we smelt an awful burning smell coming from the bedroom where the upstairs box was. At the time I couldn't trace the source of the burning smell but needless to say I switched all the power off and called the emergency number.

To cut a long story short, the power was eventually fixed in the early hours of the next morning but the V+ box was still not working. I called virgin support again about an hour ago and they said it should all be working and an engineer is on his way to look at my setup. Anyway, in readiness for the visit of the engineer I looked again at the virgin box upstairs and to my utter horror I noticed that the coax cable going into this box had most of its insulation burnt and charred! Obviously now I know where the burning smell came from.

This has left me extremely concerned about the safety of the cable installation as a whole. What if I hadn't been here to switch of the power? We could have been asleep and it could have happened then. I am certainly going to get rid of the box upstairs as a result and I wonder now how I can make more people aware of this potential danger.

I would welcome any advice about this as I am really concerned about the safety of these Virgin cable boxes and where I go from here.

I suspect that the commercial power cable in the footpath has become faulty through either damage to it by third party OR a joint has become wet and blown. Unfortunately what can happen is that the commercial power cable is situated right next to the Virginmedia ductwork, when there is a fault this can explode,burn ect if the ductwork is next to it it can result in damage to the ductwork and cabling within it.

Now this part i'm guessing in your situation, it could be a possibilty that this has happened and the drop cables within the ducting have come into contact with the live commercial power cable?????

As already stated i'm guessing this part so DO NOT AUTOMATICALLY ASSUME THIS HAS BEEN YOUR SITUATION WITHOUT FIRST CHECKING with Virginmedia or the local energy provider in your area.

OR there might have been a fault with the Virginmedia STB as a result of the fluctuating power levels, and somehow it's done the damage???

Again this is just a guess based on YOUR info given.

You should have isolators fitted on your installation to give SOME protection from power surges either way. Do you have these fitted??

Kymmy · 13-11-2009, 13:41

Quote:

Originally Posted by speedymove

Hi Kymmy, true enough but the fact that every other piece of electrical equiptment in the house survived and showed no adverse affects from the power drop is cause for concern. Why is it that just the coax to the second box burned and nothing else.

Because the faut would have been in the cabinet, which could be a street or two away and maybe even on a different little substation..

Also some stuff is more susceptable to low power causing problems, to get techie a badly made switch mode PSU can open up the voltage line if the power drops and it has a fault, so instead of getting 12v it's not uncommon to get a to higher..

Lightning strikes (miles away) and other problems could also exhibit the same symptoms

speedymove · 13-11-2009, 14:14

Thanks for all your replies, it is much appreciated. I will let you know what the Virgin engineer says after he gets here.. Any minute now... I hope..

sollp · 13-11-2009, 14:24

Quote:

Originally Posted by heero_yuy

I suspect that you lost the neutral connection back to the substation, the voltages then depend on the relative loads on the phases,(tech: the connections of live to homes is rotated about the three phases to try and balance the loads) there is usually some sort of local connection between neutral and earth. I guess that the power was using the earthing of the coax to find it's way back to neutral.

This happened to the power near where my mother lives, the power is on overhead lines, this time it blew out almost every bit of kit. Think you were lucky.

Just make sure that the STB has enough ventilation and is not in a position where it's being knocked or moved about constantly, you'd be amazed at the state of the STB's can be in in a small number of customers houses.

speedymove · 13-11-2009, 15:26

Well, the Virgin engineer has just been and checked it all out. He says he has never seen anything like it in his life and can't understand how the coax could burn like that. Incidentally, the cable is also burnt down by the tee connection outside as well!

He is going to file a report with his boss about it. The internet and phone are back up after he replaced the bad cable and connections. All be it the Internet is only running at 1.54 Mbps when it is usually around 19 Mbps. TV is still not working, very blocky and glitchy. He said that the signal coming in is extremely low. Another engineer is going to have a look at the local virgin distribution to see what is going on tomorrow morning. I suspect it also got fried by the power drop.