Avoiding power outages, maintaining a high level of availability for service networks, ensuring the safety of internal and third parties, and continuously adapting to technical developments are just a few of the factors impacting utility companies for maintaining safe and reliable systems. Live line work has proven to be a solution for improving continuity of service by reducing both power outages for maintenance to be performed as well as outages due to incidents.
Why perform work energized?
- Critical circuits needing relief, whether it be from routine maintenance to potential upgrades, are usually the most challenging to schedule outages
- System operating costs, schedule delays, system risks associated with line equipment switching and grounding can be reduced by performing line work while keeping the line(s) energized
- Performing upgrades on systems with increasing load and demand enable consumers to receive reliable service while allowing utilities to continue to generate
Benefits of Performing Work on Energized Systems
- Maintain continuous operation of critical system lines and infrastructure year-round without interruption.
- Increase system capacity to existing lines and generate new revenue streams.
- Reduce system operating costs, schedule delays, and system risks associated with line equipment switching and grounding.
- Avoid requirements for new rights-of-way for installation of redundant or temporary lines during system work or upgrades.
The National Powerline Difference
- Innovative and field-proven energized work procedures and techniques.
- Turnkey projects up to 500kV requiring no outages.
- Energized installation of conductor and OPGW.
- Insulated hydraulic line lifters for vertical/horizonal line and single/bundle conductor construction
Almost any maintenance task can be completed on an energized system. National Powerline has experience performing maintenance at voltages up to 500kV, including:
- Structure repair or replacement
- Insulator replacement
- Modification of structures, cross arms, or insertion of structure body extensions
- Line hardware repair or replacement
- Spacer and damper additions or replacement
- Marker ball and bird diverter additions or replacement
System Upgrade or Rebuild
Utilizing specialized tools and techniques, National Powerline can upgrade or rebuild any transmission and distribution line top to bottom without an outage. National Powerline Energized Services has experience with all aspects of this critical activity.
- Structure foundation repair
- Structure upgrade or replacement
- Energized reconductor
- Single to double circuit system upgrades
- Existing circuit voltage upgrades
- Upgrade of existing static to Optical Ground Wire (OPGW)
Energized Substation Maintenance
While most live line work taking place across the country primarily involves overhead lines, a limited number of contractors, including National Powerline, have ventured into performing energized work within high voltage substations. This complex work requires extremely skilled personnel to safety perform. National Powerline has the expertise, personnel, and equipment to support a wide range of offerings up to 500kV with no impacts to power delivery and service reliability.
- Insulator replacement
- Breaker repair or replacement
- Bus repair or replacement
- Repair or bypass of jumpers and switches
- Disconnect switch re-alignment or repair
Safe Work Execution Techniques
This method can best be appreciated by watching a bird perch on an energized conductor. Since the bird does not make a path through which line current may flow, it can remain on the energized conductor comfortably, even though its body has become electrically charged to the potential of the line.
The same is true for a line worker on an insulated platform approach an energized conductor. The line worker can work safely on that particular conductor if the body does not become a path through which line or charging current may flow.
Hot Stick Method
Hot stick, or distance technique, uses an insulated glass stick to protect the line worker from a grounded source while working on live lines. Generally, this technique is suitable and widely adopted up to 220kV potential.
Hydraulic Line Lifter
Through partnership with LineWise, National Powerline has rated and insulated overhead transmission line lifters that enable our line workers to safely transfer conductor loads from existing structures to this equipment, allowing them to conduct a wide range of services while keeping circuits energized and in service.
High Induction Stringing
As existing systems experience increases in load and customer demand, National Powerline has the ability to install new or replace existing conductors while keeping the system in service using high induction stringing. With this work method, induced voltages from adjacent circuits are transferred to a de-energized circuit or line. Using specialized tooling and equipment, coupled with detailed work execution procedures, National Powerline is able to perform this work technique energized.
Aerial line services used in new construction, repair, and maintenance have proven to boost productivity and efficiency compared to ground-based methods that require large teams, significant heavy equipment, and more time.
National Powerline’s aerial crews in helicopters use specialized tools and equipment to provide a safe and efficient alternative to ground-based services with measurable operational cost savings.
Workforce Development & Training
Through sound investment and an unwavering commitment to the safety of our employees and the communities we serve, National Powerline trains our employees to be industry leaders in their specialty trades. Our approach is multi-faceted and mutually beneficial, enabling our employees to take advantage of opportunities to advance and diversify their careers while providing National Powerline with a best-in-class workforce.
Our energized services division has developed and implemented robust work force development and training opportunities to foster a positive, inclusive working culture founded on unwavering values of safety, quality, and sustainability.