Dangerous Open Neutral, CATV drop being used as neutral (HD)

Testing a communications drop for signs of a loose or open neutral electric service. This method can ensure communications technicians do not get injured by completing an energized circuit and protects customers equipment and homes

EDIT: when I say “substation” I mean it’s returning to the transformer. Sorry for the error, and I’m not YouTube savvy enough to fix post publishing.

[matthewbeasley]

A little nitpick: The neutral current isn't going back to the substation, it is just going back to the transformer on that pole. Wherever the CATV and power grounds connect is where that current will flow and then via the utility neutral it will go to the center tap on the transformer.
If the neutral wire is broken going down the street, then the primary current imbalance would go down the CATV messenger wire to the far side of the break.

[rupe]

as someone who did electrical troubleshooting on a regular basis with a generator company, I can tell you I saw plenty of toasted or open neutrals over the years... but never gave it a second thought that the CATV line would be a better neutral than the ground rod at the house. That's just scary!

[brody]

This happened to me about 25 yrs ago as a cable install/repaiir. Came in as no picture drop looked clean and using amp clamp got no readings. Installed a new aerial drop landed at the ground block, when attaching to tap a blue arc appeared and I then knew it was an open neutral. Needless to say there were a few items in the customers house that no longer worked. Happy to be alive and nobody got hurt.

[grabasandwich]

I was a telco contractor for 15 years and saw a few weird things, but a couple years ago I moved over to coax. I've already seen a few melted drops, and nobody's really stressed the importance of this scenario.

One was melted at the ground block inside, and it sparked when I cut it, as well as when I touched it to the cast iron plumbing stack.

Another house had a history of outages going back TEN years! I tried using my voltage detector (big yellow one) but like you said, it didn't show anything.

I then did some digging online and saw some horror stories from open neutrals, like house fires.

Anyway, thanks for sharing. I might look for an inexpensive amp clamp now!

[lxiflyby]

As a utility lineman, we actually see this pretty regularly. I’ve even seen it where one place had almost 20amps on the cable drop, and yet the problem was at the neighbors house (neighbors neutral had burned open and the house was running off the cable tv drop, and the current was going across the street through their cable tv drop onto their service neutral)

[amazing]

For the homeowner... You know how the lights dim slightly when the fridge motor starts?
If you ever see some of your lights get =brighter= instead of dimmer when a heavy load (such as motor startup) is applied, you should suspect that there is an open neutral. The open neutral causes an unbalanced load, so that as one leg of the 120/240 supply carries a heavy current, the other leg rises in voltage. This is a dangerous condition, because the neutral, normally at ground potential, is protecting you from disastrous overvoltage that might occur if a transformer failed or if a high-voltage line fell down upon the drop to your house, as (for instance) in a traffic accident.

[jayson]

Kudos for seeing that before you touched the cable line! Good Job! Keeping yourself and the customer safe.

[paulrhoads]

I worked for the telephone company for 41 years as a cable splicer I have seen this three different times.

[snowbird]

This happened to me at my home in NJ years ago. There were unusual effects of house lighting for a time. I just happened to touch the CATV drop ground and it was hot to the touch. Putting 2 and 2 together I realized the power Neutral was open or degraded. When I told the power crew about my observation they knew right away what to do and fixed the neutral. Looking back I would not recommend a homeowner touch the cable ground, but instead just calling power provider.

[framistan]

I was a cable tv technician 20 years ago and have seen similar problems.... but they are rare. That is what makes it so dangerous. Nobody expects this to happen.

[RKSNomad]

as a fiber tech, when it comes to electricity, we usually have to deal with induced voltage caused by high power lines running parallel with our transport. I've never personally dealt with induced voltage in high enough numbers to be deadly, but I had a co-worker who was shocked into a stroke that doctors compared to being struck by lightning.

[KlodFather]

Working as an engineer on a fiber cable installation in a rural area, one of these energized drops melted and dropped into the field and set it and the woods on fire. That was some of the craziest shit I have ever seen. No real danger but those guys were moving like lightning to contain the flames and prevent it from getting into the woods and starting the pines. What a mess. Everything went up in smoke.

[Leo-pdww]

3 years ago the neutral line of a 400 kV circuit disconnected and fell across a road. Fire department came along, just picked it up and dragged it to the side of the road while the circuit and circuit next to it were in service. Emergency services are instructed on how to act in certain situations, but to no avail.

[TurkeySandwichJr]

I found an open neutral caused by a tree limb falling and breaking the conductor (similar looking scenario to what you have here) and it actually caused the cable box to catch on fire and melt off the side of the house. Fortunately it was a brick sheathed house and they didn't have pine straw or anything - could have been a lot worse!

[milesparris]

I used to run an old car wash, and one day I noticed that when a vacuum would come on, the pole light above it would get really dim for a second and some of the others would get really bright. I knew there was an issue with the common but I couldn't find a problem in the wiring, so I got on the roof and tested for power at a splice where it went to the city and read about 20 volts, surged to 60 when someone started a vac. I called the city (It was on their side of the meter) but they claimed there was nothing wrong. I got a few feet of really heavy solid copper wire, cut a dozen 1 foot pieces, and used hose clamps to bridge the splice. Problem solved, and my "repair" is still there almost 30 years later.

[williamogilvie]

Well, at least there is a neutral line there. At my parent's cottage there was just one wire supplying 120 VAC. The lot owner was required to install a good ground rod. And when the ground dried out, people got shocked easily. I guess that would happen to the residents of that house if they used any electrical tools outdoors.

[AndrewPepper]

Seen that many times over the years. Usually followed at some by the messenger separating from the coax.

[wayneheigl]

there was an electrician killed near me when he went to remove the bonding ground from the cold water pipe in the basement of a house. all the ground wires on the poles going down to the ground rods in the neighborhood were removed by copper thieves . the grid was using the service drop ground to the house to operate. when the electrician removed the bond from the water pipe the ground for the transformer primary was floating using any ground it could to operate. there was a 7400 volt arc that killed him. when ever i work on bonds i check every thing for current flow and i cover my self with a set of heavy duty jumper cables before removing any bonding wire to clean or replace.

[rayarsenault]

1:13 there is current flow, else you wouldn't have amps. there is no potential to ground till you open the circuit.
on the house, the ground block for the cable line is picking up the lost neutral, taking it back to the pole, and grounding through the case of the devices. if you pull the wire off the device, and measure device-cable, you will see potential.
The triplex should also be grounded in the meter housing; so it looks like the customer actually has 2 problems.

[thedopplereffect]

Why isn't there a safety device to automatically detect this condition and break the circuit?