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Recently I was asked to investigate another stray current problem. A cablevision technician removed the cable drop from a home, which resulted in power shutting off at the home. The CATV technician learned about this event when the homeowner came from the home and asked, "Why did you cut my lights off?"
After further investigation we discovered an open neutral between the service and meter base. This open neutral may have occurred due to storm damage on the meter base and weather head.
An electrical contractor a couple of weeks prior to the open neutral discovery replaced the damaged meter and weather head. A potential shock hazard exist with open neutral conditions; CATV and telephone technicians, as well as water meter people must be aware of this dangerous issue to prevent fatalities.
It is important that the technician, when removing the cable drop use proper procedure. In this case if he had gotten in series with this circuit he would have received approximately 100-120 volt shock.
It is important that the electrical contractor do the proper check after reenergizing a service. Open neutrals have been problems since the beginning of electrical distribution.
However, some utility primary cable problems with concentric neutrals are becoming more of problem because of improper installation and aging of the underground primary cable. I have a diagram of how this problem occurs if you want to see it.
I have been teaching this information to several telecommunication utilities/plants.
This is part of a series of case studies I am doing on the effect of stray voltage/current on sensitive electronic equipment and information technology. If you have related cases please let me know.
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