Civil Engineering Magazine – Unexpected Consequences
As aging infrastructure continues to deteriorate, city engineers and utility engineers nationwide are grappling with an unanticipated ramification of this deterioration: exploding manholes. Although manhole events are still relatively uncommon, they pose a threat to public safety and require both reactive and proactive solutions.
Seattle City Light Crews Keep Streets Safe – T&D World
Three years ago, a dog was electrocuted after touching an energized metal streetlight handheld cover. After this incident, Seattle City Light began to explore methods to test its aging underground distribution system for contact voltage, also known as stray voltage.
Electric Energy T&D – Surveying for Electrical Losses
UK Power Networks (UKPN) is on a mission to reduce system losses and is considering some unconventional means. Conventional wisdom is that electric distribution system losses are primarily from two sources; resistive losses and transformer excitation losses.
Structured Methodology for the Investigation of Contact Voltages
Utilities are often asked to investigate and determine the cause of elevated voltage in the urban environment. By understanding proper measurement techniques, and how to interpret readings and the possible sources of the voltage, investigators can reach speedy and accurate conclusions, and eliminate unwanted voltage.
Technique for Accurate Voltage Measurement of Energized Street Level Objects
Abstract – The demand and volume of “stray voltage” testing in urban areas have increased greatly in recent years. Several techniques for detecting energized objects are in use but once detected, confusion can arise between diagnostic and repair groups about the presence and magnitude of the voltage. No standard technique exists for making voltage measurements in the field. Accurate, repeatable voltage measurements are crucial both for reliable reporting and for effective cooperation between testing technicians, diagnostic technicians, repair personnel, and other parties with a stake in effective mitigation of potentially hazardous conditions. The described process eliminates sources of measurement error to ensure parity among measurements made by different individuals. Particular attention is paid to the choice of a ground reference point with no elevated potential and a low impedance path to ground.
Using Harmonic Measurements to Aid in Source Determination during Elevated Voltage Investigations
Abstract – By measuring the total harmonic distortion of the voltage waveform during elevated voltage investigations engineers can quickly identify the probable source of the elevated voltage.
The Results of Asset-Based Manual Testing of Utility-Owned Objects for Contact Voltage in New York State
Abstract – Based on data publicly reported by utilities in New York State, the effectiveness of asset-based manual testing in reducing electric shocks can be evaluated. The data also provide insights into the relative reliability of various classes of distribution assets.
Guidelines for the Design, Installation, Operation & Maintenance of Street Lighting Assets
The Guidelines for the Electrical Design, Installation, Operation, and Maintenance of Street Lighting Assets were created in response to electrical contact incidents experienced throughout Ontario. The ESA invited stakeholders to participate in writing street light asset guidelines. The stakeholders represent street light asset owners, contractors and consultants. The primary purpose of the guideline is to document best practice information from professional practitioners for the safe electrical design, installation, operation and maintenance of roadway lighting systems in Ontario to mitigate electrical hazards to the public and comply within the requirements of the Ontario Electrical Safety Code (OESC).
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