Steve Griffith, Industry Director, NEMA
As utilities across the world continue to grow the smart grid infrastructure, existing electric meters are being replaced with new smart meters that include two-way communication features. The benefits with smart meters are numerous; they provide real time energy usage information and improve power outage detection and notification.
New smart meters are often installed in preexisting meter sockets. Meter sockets are expected to operate safely for many years, but the safe operating life of the meter socket may be reduced by many factors including (but not limited to) excessive moisture, environmental contaminants, frequent changing of meters, excessive electrical load (overload or short circuit), vandalism, ground settling, and storm damage.
As utilities move to two-way communications for meters and remote meter reading, the opportunity for inspection of meter sockets is expected to decline radically. For this reason, NEMA strongly recommends that all existing meter sockets be thoroughly inspected when electrical meters are installed. Inspection criteria should include (but not be limited to) indications of excessive heating, corrosion, loose connections or components, deformed socket jaws, broken components, failed insulation, damage due to ground settling or vandalism, or any exposed live parts.
Furthermore, with the increasing proliferation of alternative energy sources such as solar and wind, a popular way to connect an energy source to a premise’s wiring and the utility is through the use of a meter socket adapter. These adapters are also often used for other applications such as connecting backup generators and reconnecting an existing service that changes from overhead to underground.
Stakeholders in the electrical industry have raised a number of concerns about the installation of meter socket adapters. For example, manufacturers are concerned that adapters that are plugged into existing meter sockets may have only been tested to be installed in new equipment.
Utilities are concerned that contractors are installing equipment in the meter socket that is not under the utility’s control. For this reason, some utilities (such as San Diego Gas & Electric) install and maintain meter adapters themselves
Inspectors are worried that if the installation of meter socket adapters is not under their inspection responsibility, that they might be unsafe. The National Electrical Code (NEC) clearly states that if an installation is “under the exclusive control of an electric utility,” it does not fall under the scope of the NEC and would not be inspected by the local electrical inspector.
On the other hand, solar contractors and installers would like to be able to use meter socket adapters even more. They often provide an easy way to avoid having to change out an old electrical service when installing a solar system. This helps to keep down the cost of solar installations and can often mean the difference between whether or not a particular installation works out financially. But it also means that some older, questionable service equipment might be left in place when it really should be replaced.
At the January 2017 Electric Utility Service Requirements Committee (EUSERC) meeting in San Diego, the subject of meter socket adapters was raised by Southern California Edison and some of the other utilities. They are concerned about installations that they are seeing in their service territory and unsure whether they should be installed by the utility or a contractor. A task group was formed that included a representative from UL, NEMA’s West Coast field rep, and representatives from SDG&E and SCE to investigate further the issue of meter adapters. In future blogs on this subject, I will give updates on the group’s progress.