Deliverables on Underground Assets
Recent deliverables on distribution underground assets.
2023
| Number | Name | Brief Description |
| Improve UG Asset Life and Performance | ||
| 3002027534 | Distribution Underground Switch Guide: 2023 Update | This report is an update to a multi-year project investigating the life cycle performance of MV UG switches. The work from this historic research thread has produced a body of knowledge around underground switch life cycle performance. This report includes content for inclusion in the Medium Voltage Switch Design Review and Condition Assessment Reference Guide, under development, including chapter drafts for the Introduction and Overview, Switch Materials and Applications, Review of Industry Standards, Case Study Examples and References chapters.
Findings from this work can be used to inform your material specifications, inspection / maintenance and diagnostic approaches to achieve better performance of your switch fleet. |
| 3002026866 | Cable and Cable Accessory Performance: 2023 Update | This report is an update to a multiyear project investigating the performance of medium voltage (MV) cable and cable accessories. The 2023 research sought to understand and illustrate the impact of various design and craft practice approaches on the anticipated health and performance of MV cable accessories. The report provides results from forensic examinations of early life failures of cold shrink cable joints installed on EPR insulated cables, installation damage truncating the life of a trifurcating cold shrink transition joint (PILC-to-EPR), and an early life failure of a pre molded straight joint (EPR – EAM).
Findings from this work can be used to inform your material specifications, inspection / maintenance and diagnostic approaches, and craft practices associated with accessory preparation to achieve better performance and improved reliability. |
| 3002027553 | Medium Voltage Cable Aging: 2023 Update | This report describes two research streams into the performance of medium voltage (MV) EPR insulated cables. The first describes the development of a research project to understand the expected performance of new, non-traditional, EPR insulation technologies, including lead free EPR and EAM. The second is focused on documenting cable knowledge in the form of references to assist utilities in managing their cable fleets.
This report contains the first four chapters of a cable reference book intended to provide historical background and practical insight into the aging performance and management of medium voltage cables. |
| 3002026934 | Underground Distribution Automation Assets | This report summarizes work performed in 2023 to examine the life cycle performance of MV automated UG switches. The report includes findings from the forensic examination of a failed G&W Trident-SR, an automated underground switch. The report also includes discussion of inspection tools and technologies for distribution automation assets based on learnings from multi-year research into these assets.
Findings from this work can be used to inform your material specifications, inspection / maintenance and diagnostic approaches to achieve better performance from your automated switch fleet. |
| Tools for UG Ascertaining Asset Health | ||
| 3002026867 | Infrared Thermography in Underground: 2023 Update | This report provides an update of a multi year reach project to inform the use of IR as a diagnostic tool for underground cables and cable accessories. The report includes a description the test bed which will be used to examine heating of cable system components subjected to loading in the laboratory including the data to be acquired and analyzed, and a description of the test approach, including the analysis used to select representative load profiles to be used in the testing.
This research is aimed at producing information to better understand the implications of design and preparation practices on connector performance and life, and to inform infrared thermography. |
| 3002026868 | Network Transformer Monitoring: 2023 Update | This report describes the test set and results from testing of a remote DGA monitor designed for use on network transformers when deployed on units using ester based insulating fluids. In addition, the report includes a Case Study of a utility approach for leveraging dissolved gas analysis results to manage their network transformer fleet.
Results from the research will inform remote gas monitor selection, and aid utilities in incorporating DGA into their network transformer fleet management approach. |
| Structures | ||
| 3002026870 | Manhole Event Research Summary 2019–2022 | This report is a Powerpoint presentation which summarizes key learnings from a multiyear project investigating risk mitigation of manhole events, including testing to understand gas produced when LV cables overheat and arc. This presentation will underpin a 2024 taskforce webcast to identify next steps in this research.
Results from this research will inform sensing technologies for early identification of conditions which could lead to manhole events, as well as remote manhole monitor selection, deployment, and settings. |
| 3002026869 | Equipment and Structure Corrosion: 2023 Update | This report is an update of a multiyear research project to better understand the corrosive environment of underground vaults and how it may impact metallic components to inform tank material selection and corrosion management approaches. The report includes a review of corrosion science techniques for determining the corrosivity of vault water solutions and describes field sample sets made up of metals that are being deployed and aged for one year in in-service vaults.
Results from this research will aid utility fleet managers in managing corrosion of UG assets. |
| Knowledge | ||
| 3002026871 | Bronze Book: 2023 Update | The Bronze Book is a reference aimed at utility engineers and personnel involved in the planning, design, manufacture, installation, operation, and maintenance of underground distribution systems. For 2023, EPRI added a new chapter on Cable Quality.
The Cable Quality chapter includes content on cable manufacturing processes and modifications to design, manufacturing, materials and testing approaches to improve cable quality. It also describes where problems can occur and provides guidance for collaborating with cable manufacturers to improve specifications and reduce the likelihood of cable system failures. |
| UG Repository | Underground Practices Repository_2023 | Provides access to an online repository of underground practices to facilitate comparisons and aid decision-makers in identifying practices in place at other utilities that can be applied to their utility to improve performance. |