The Lemon Creek substation is a key site for AEL&P in supplying backup power and electrical distribution to the city of Juneau. It is located near a landfill, a food source attractant to many species of avians. AEL&P had been proactively investigating and testing several avian protection options available in the marketplace. These efforts helped, but there was still a need for further improvement. Following a significant eagle-caused outage that was reported on by the media, the Hubbell Greenjacket Team reached out to AEL&P to offer assistance in solving these issues.
A commonly overlooked consideration in arrester applications is the impact of lead length. The inductance of lead wires can produce an inductive voltage drop which in turn will lower system protection. This voltage drop only occurs if the lead carries surge current and is in parallel with the equipment being protected. This resultant voltage is added to the discharge voltage of the arrester during a surge event, thereby reducing the protective margin of the system. The lead wire’s inductance is not strongly influenced by conductor diameter, but rather of overall lead length. Therefore, care must be taken to keep the lead length to a minimum in both distribution and substation applications.
When securing a fiber line to a pole, building or at mid-span, installers must be careful not to cause undo stress or strain on that fiber line. If they do, it can cause a break in the line, which in turn would cause an outage/disruption in service. Fixing this would be very expensive and time consuming, not to mention a huge inconvenience for everyone involved (contractor, worker, the public and customer).
The torque-to-capacity relationship for helical anchors and piles is an empirical method originally developed by the A. B. CHANCE Company beginning in the late 1950s. Today, the relationship is well recognized in the deep foundation industry. It is commonly referred to as torque correlation.
With the recent and upcoming revisions of IEEE C62.11 and IEC 60099-4 surge arrester standards, writing a technical specification for arresters can be challenging for both new and experienced engineers. Most arrester manufacturers have a dedicated team of engineers who are familiar with the evolving standards and can support the revision and/or creation of arrester specifications.
Not sure what the proper bushing replacements are for your in-service bushings? Hubbell | PCORE® Electric can provide a custom cross-reference guide to help!
Insulating rubber blankets for energized line maintenance come in a variety of sizes, classes and types. Each Class of insulating blankets has its own maximum use and testing voltages, as described in ASTM D1048 (see Table 1). The higher the class rating, the higher maximum the voltage rating is for the insulating blanket.
Topics: Lineman Grade Tools
Predicting the holding capacity of an anchor can be difficult due to soil variations at different depths and different structure sites. It is critical to understand anchor capacity to ensure the integrity of your guyed structures.
The reliability of our overhead power and communication lines is as important today as ever before. The integrity of overhead construction often relies on guy anchor systems that can be trusted when put to the test during high wind loading situations and when tree branches come into contact with the lines. If an anchor pulls even the slightest amount, it causes the top of the pole to lean. This can cause improper line sag resulting in clearance issues.
Repairing a bushing is less expensive than purchasing a new bushing and you are able to maintain all of the original dimensions.
A typical bushing repair is a regasket of the bushing or a recore and regasket of the bushing. When a bushing leaks; however, tests well, a regasket will be performed in which the sealing components are replaced. When a bushing tests poor, a recore and regasket will be performed. During the recore of a bushing the bushing core will be replaced with a new PCORE® POC type core. Repaired bushings ship with the same warranty as a new bushing.