Search:
Categories:
Links:
Don’t Skip the Survey
During the follow-up on an EXACTER Group location field review, we were directed to what seemed to be a mistaken location. Several Events had been aggregated into one significant EXACTER Group, but when we arrived at the location we found it to be midway between two poles. There were splices on the line, so these were inspected with no trouble found. That is when we learned the importance of completing a site survey to its conclusion. We used an RE 330 to do a sweep of the location. That is how we noticed that the Event emission was coming not from the line but from a location perpendicular to the line. We continued to follow the emission source to a house about 200 feet off the road. The survey tool indicated a steadily increasing RF emission. The sweep of the area quickly located the source of the emission: the service Triplex. Using the RE 330 and the RE ultrasonic parabolic sensor, we followed the service entrance to the meter socket. Once we confirmed the source of the emission, an emergency ticket was issued and a meter technician was dispatched. We contacted the owner of the home to let them know that there would be a short interruption of service while the problem in the meter socket was investigated. The Meter Technician removed the meter from service and the emissions ceased, obviously a load-side problem. The problem was immediately apparent. The right-hand load-terminal was badly etched and blackened from arcing and heat. Our first thought was that the meter had not been properly seated in the socket. So, the meter was reinstalled following a thorough safety inspection. At first there were no emissions. But, in about 30 seconds the emissions began again. The emissions were low level at first, but returned to their normal pre-inspection level within a couple of minutes. As a final step, we discussed the hazardous situation with the customer, who agreed that an electrician would be called immediately to replace the failing meter socket before a heat-related failure initiated a fire. Luckily, the weather was mild and there were no heavy loads in the home to exacerbate the problem. The sensitivity of EXACTER located the problem which was hidden from view off the road and avoided a disaster. This really demonstrated the importance of following up on EXACTER Group Events with a site survey to locate the problem and resolve the arc emission. 
Hot-Line Clamp Gets Really Hot
During an EXACTER survey, an emission source was located and logged as an EXACTER Event. Upon review of the location information, it was noticed that this circuit also had a lot of trouble with missed AMR meter readings. We used RE locating tools to quickly pinpoint the arc-emission source that had been located during the EXACTER survey. The source seemed to be the conductor at a hot-line clamp. When the clamp was removed, there was obvious damage to the connector. The clamp was nearly burned through. Luckily, the clamp sustained most of the damage and the conductor seemed to be okay, although we will be watching it. As a secondary benefit, following the replacement of the clamp on a new area of the conductor, the meter-reading system started reporting 100% readings. EXACTER provided the information we needed to avoid a downed conductor and overcome a vexing AMR issue.
Hot-line clamps are used in a variety of connection situations. Everyone knows that the conductor must be cleaned to avoid early failure due to high-resistance connections. And proper installation procedures are well understood. But there are times that something can go wrong.
EXACTER vs. Telecom
An example of this happened at a southern EMC installing a new AMR program. Communication difficulty was a constant problem and halted installation work early on. The system provider and the utility worked together to solve the problem and exhausted all conventional troubleshooting methods. The problem could not be located. An EXACTER survey located a corroded ground at a telephone pedestal. When the ground wire was lifted, the meters started communicating.
Deployment of a reliable power-line-carrier (PLC) AMR system is a difficult task, but when power line noise disrupts communication, the meters stop reporting.
click thumbnail to view larger image
©2007 Exacter, Inc.
Powered By Wordpress