Preventing Electric Meter Fires
Electric meter fires, when they occur, can put utility customers, workers and company reputation in jeopardy. News coverage of these events at times struggles to determine what caused the problems.
Electric meter fires, when they occur, can put utility customers, workers and company reputation in jeopardy. News coverage of these events at times struggles to determine what caused the problems. Yet much is known on safe installations. A body of knowledge has emerged around socket safety: what to do before, during and after installing advanced meters.
Scott Mann of Brooks Utility Products and Sangeet Dutta of Apex CoVantage have extensive knowledge and experience in hot sockets and meter socket safety.
Mann addresses the issue with equipment and training: thermal imaging equipment, socket testers and thorough inspection techniques, for example.
|A culture of safety means full personal protective equipment is worn “seal to seal” on meter sites.|
Dutta approaches the issue through work flow management: forced march work flows, fault-resistant work flows, business process and enterprise resource planning (ERP) principles specifically for advanced metering infrastructure (AMI) and other smart grid infrastructure.
Both see socket safety training as vital. Brooks Utility Products instructs installers at metering school seminars across the country. Apex CoVantage trains, tests and certifies work forces before putting them in the field to work for utilities. Each has worked with utilities, both ameliorating damage after fires and creating practical solutions that reduce utility risk before metering deployments.
With roughly two-thirds of U.S. electric meters yet to be converted to smart meters, these perspectives might help those remaining utilities install advanced meters safely.
Why do meter fires continue to be an issue for utilities?
Mann: Hot sockets are a very serious and very prominent concern for the metering industry. Meter socket safety issues, including fires, are nothing new. Due to the rise in AMI deployments throughout the world and more readily accessible information, the number of reported hot socket incidents is on the rise. There has been significant debate both inside and outside the industry about the root cause of these events. Are they caused by the new meters’ being installed? Perhaps a defective meter socket is to blame? Could it be that the meter was improperly installed? Some have suggested environmental factors such as vibration are to blame.
Despite the industry’s collective experience in planning and executing meter deployments, we seem unable to anticipate the impacts of product life cycle and other variables on the safe operation of metering equipment.
|This worker is guided by fault-resistant work flows through areas of common error or high risk.|
Factors outside the scope of planning-age and condition of existing equipment and who might conduct the inspection cited here-can undermine the success of a meter deployment with potentially disastrous results. Brooks Utility Products has its ears to the ground and is committed to delivering solutions and providing leadership toward root cause consensus that will help the industry overcome this socket safety issue.
However, there are sound principles, practices and equipment standards that can be applied any time crews are working at a meter site, inside the socket or inside the meter that will reduce risk considerably. There are steps that can be taken to fix issues once they are detected to improve safety for work crews, as well as for homeowners and businesses where meters are sited.
Dutta: Meter fires are an important and sensitive issue that has particularly come under public scrutiny during the widespread infrastructure upgrades of the last decade as utilities increasingly move to advanced meters. Any time a utility invests in advanced meters, they are conducting a vital equipment upgrade to one of the most visible, customer-facing elements of their power infrastructure. Consumers often have questions about what this technology is and whether it is safe or even necessary. Public concern is understandable, since fires-though statistically rare-can have tragic results. To reduce risk and liability and to protect consumers, workers and utility resources, meter installations must be completed in the safest, most transparent and efficient way.
|Safeguards begin at the job site and continue through all processes: approaching, opening, removing and installing meters.|
It is not merely a matter of looking at ways to avoid trouble, either. When utilities remove old meters, they create an opportunity to inspect equipment that may have been covered up for years, perhaps even decades. By detecting signs of deterioration or damage at the meter site and acting to make repairs, utilities can proactively ensure the safety of their networks for years. Too often, the industry has not recognized this moment as a once-in-a-generation chance to act.
While the causes of meter fires can be many and complex, a body of knowledge has emerged to reduce risk and enhance both the customer experience and the utility business case. Yet many utilities are not aware of the range of solutions available.
How do you recommend utilities reduce the risk of meter fires?
Mann: To prevent hot socket issues, one first has to understand what causes these incidents. Several features or sources can cause hot sockets, but among the most prevalent are:
- Mechanical breakdown of components;
- Excessive moisture;
- Environmental contaminants;
- Frequent meter change outs (resulting in loss of jaw tension);
- Excessive electrical load (overload or short circuit);
- Loose or melted conductors;
- Ground settling; and
- Storm damage.
Becoming informed and establishing methods to address hot socket issues is paramount for manufacturers and utilities. Not only is it critical from a PR perspective, but also from a financial viewpoint. Costs associated with socket safety issues increase the longer they go undetected. Replacing damaged equipment and components if caught early is much more cost-effective than having to reconstruct the entire service or pay damages to a consumer. Developing a process that proactively identifies and mitigates problem sites is crucial in getting in front of hot socket issues.
|A socket jaw tester, like the one pictured above, helps detect any loss of jaw tension, a common contributing factor to hot socket conditions.|
Dutta: We recommend that utilities take advantage of all of the resources available to them. One of the contributions Apex has made is developing the utility industry’s only ERP solution built specifically for AMI installations. This software, ProField, applies the widely recognized principles of business process management (BPM) to drive the training, project management and back-office quality assurance processes in support of utility infrastructure installations.
We really encourage utilities to investigate the health of their meter sites when those old meters come off to investigate the state of their infrastructure and to invest in its safety. No one wants to see a new meter go in and cover up deteriorated conditions for another few decades. Best practices for avoiding meter fires should include taking advantage of the opportunity to make vital repairs to enhance future safety.
What is your approach to detection of socket issues?
Mann: Visual inspections-covering factors such as deterioration of insulation to melted conductors-and mechanical inspections-covering variables from proper torque of wire lugs to the socket’s connection to the facility-can help in these areas. In addition, utilities can and should make use of temperature analytics capabilities provided by the meters to more precisely identify sites that are a concern.
To assist utilities in identifying these problems, Brooks is renewing the awareness of a long-standing, but little-known product. More than 10 years ago, Brooks introduced the socket jaw tester, a specially designed force gauge for measuring the insertion and extraction forces associated with installing a socket-type meter into a meter socket. The socket jaw tester provides immediate feedback on whether the socket jaw tension is adequate and less likely to result in micro-arcing. In addition to jaw tension inspection, Brooks recommends utility personnel and installation contractors visually inspect all socket parts and wiring to ensure they are in safe, working condition. The inspection of socket installations also should include a mechanical review of all hardware. Are the lugs, mounting screws and other connections tightened to an acceptable and safe torque level?
|Varieties of block replacement kits, like the one pictured above, offer ways to restore safe conditions to deteriorated sockets or socket components.|
Dutta: We combine the best of human initiative and automated approaches to advance safety in all areas of an AMI installation. We begin with the software, which contains work flows’ incorporating knowledge of best practices and areas of potential problems. When a worker arrives on-site to install meters, he or she comes equipped with a mobile handheld device preloaded with a series of forced march work flows. These work flows then guide installers through each assigned activity with step-by-step instructions, increasing the likelihood of a successful installation while greatly reducing human error. For example, a strict “work safe or not at all” philosophy is embedded into the work flows, requiring full crews to put on personal protective equipment and wear it “from seal to seal” in meter work.
We have developed socket safety protocols to anticipate and address safety issues for every element related to meter, site and socket. The protocols cannot be skipped, thus ensuring every meter is fully assessed and problems acted on. The essential inspection protocols we recommend include:
- Initial external visual inspection
- Site, power source
- Worker equipment and safety gear
- Meter and socket for signs of past arc flash
- Internal visual inspection
- Socket interior around meter
- Line tension
- Corrosion levels
- Jaw conditions
- Evidence of theft
- Foreign objects
- Photo of meter socket sent to off-site experienced meter technician for secondary analysis
- Mechanical inspection
- Jaw tension
- Heat sensors
- Closing external visual inspection
Following these protocols allows advanced meter installations to proceed on time, within budget and safely.
When socket or meter safety issues are identified, what can utilities do to prevent or mitigate risk and damage?
Mann: Once a problem has been detected with the socket, there are several means to address the situation, largely dependent on socket ownership. In situations where the consumer owns the socket enclosure, the utility may notify the consumer of the issue and require the consumer to replace the entire service entrance. This can be extremely expensive because it might require other equipment to be brought current with local and national electric codes. Passing on significant cost to the consumer in light of an inspection related to a change in meters might result in bad PR for the utility. An alternative might be lower cost mitigation performed by the utility.
Brooks offers several mitigation solutions to help replace socket components. Tools such as the universal block replacement assembly, which allows field replacement of most 200 Amp single-phase S-base meter socket interiors, and the universal replacement terminal block, which allows replacement of existing A-base terminal blocks, allows the socket enclosure to be salvaged and costs to remain relatively low. The universal block replacement assembly was developed in the mid-1980s for situations where the utility could not press the consumer to address an unsafe socket situation, and utilities needed low-cost solutions to address problem installations. Should a utility find sockets in disrepair and require wholesale upgrade of the installation, we provide protective nonconductive socket covers, rings and seals to ensure customer safety.
|Enterprise resource planning software specifically for AMI guides workers through installations using handheld devices.|
Dutta: The protocols above provide a glimpse into the larger process for acting on issues as they are detected. At each step, installers can escalate the process. If jaw tension is poor, if there are scorch marks from a past arc flash, if a part appears to have been stolen, the worker has a clear sense of what to do or not do and who to contact for resolution. Forced march work flows lead installers to take the appropriate action in each case.
In addition, we do something unique to provide additional checks and balances. Each worker’s handheld device includes a camera function to record any conditions of concern and send visual images to an off-site experienced lineman. Each time a meter is removed, the trained installer and the off-site experienced meter technician perform empty socket analysis to reveal unsafe conditions and allow utilities to restore safe conditions across all their meter sites.
Because real-time communications are built into the technology, field-workers, supervisors and utility management can communicate readily to address issues promptly as they arise. This also increases project efficiency.
What training approaches do you recommend for utility work forces working with sockets?
Mann: Meter schools are a great resource. We do a lot of instruction at these, usually weeklong courses for continuing education credits. We have seen an increase in the percentage of schools that offer socket safety topics during the past year, especially. We spend significant portions of the classroom sessions teaching workers not only how to stay safe, but also what techniques and tools they can use to identify risky situations and lessen risk and prevent problems. We put tools into the hands of students and familiarize them with the ways that a jaw socket tension tester can reveal signs of trouble or a heat-detection gun can help them avoid potentially harmful scenarios.
Dutta: Some utilities use our turnkey solution that includes installation services, as well as full use of our ERP software. In other cases, utilities license our technology and use their own work forces. Whatever the model, we recommend that training includes both basic and advanced safety techniques and that installers become adept at recognizing the signs of hazards.
Apex has developed a rigorous training and certification program consisting of more than 60 hours of classroom instruction and field training. Installers learn to recognize and address the symptoms and factors that can affect socket health. They come to grasp the significance and consequences if no action were to be taken, including possible meter blade overheating, meter damage, socket damage, loss of phase and even socket or house fire. Once certified, a worker receives 100 percent monitoring in the form of shadowing by an experienced supervisor. Even experienced workers are subject to quality control through random field inspections.
|New workers must be thoroughly trained, certified and monitored. Even installations performed by experienced workers should be quality checked regularly.|
When we are not hiring or training the work force, we simply share knowledge to support the utility’s success.
What works well for utilities that have encountered active signs of socket danger?
Mann: One of the utilities we have collaborated with is American Electric Power (AEP). They have developed an aggressive internal program for identifying and addressing socket safety issues through a temperature analytic program. AEP has shared much of its work with the industry at conferences, and its insights are valuable for others to draw upon. The findings of the AEP temperature analytics program support the need for vigorous visual and mechanical inspection of the socket each time a meter is installed or removed, regardless of socket and meter age.
Dutta: Sometimes you don’t know what you’ll find until meters have been disconnected and the socket and wiring are exposed. One utility did not get far into a meter upgrade project before they discovered an abundance of deterioration in old meter sites. They reached out to us early in that deployment and we trained their installers to recognize symptoms of trouble. We created new work flows to ensure proper inspection of their existing network to proactively safeguard equipment, lives and the utility’s investment.
Their swift attention to underlying issues was a smart investment in reducing risk and ensuring safety during installation and for years to come. It was a prime example of a utility’s taking preventative steps to maintain the integrity of its existing network. Utilities that are proactive in addressing their AMI infrastructures are setting good examples for the industry. They protect their workers and customers from harm, and they safeguard their reputations and that of the AMI industry.