Highway Feeder Circuit Conversion & Phase Correction

Oncor needed to convert an overhead feeder circuit crossing I-45 to an underground crossing to enhance reliability and reduce exposure to external hazards. The project required:

• Installation of two new poles for the underground feeder risers.
• Completion of a bore under I-45 for underground conductor placement.
• Pulling and terminating 1000 MCM aluminum conductor while maintaining correct phasing.

However, phase markings were misaligned after installation, which could have led to incorrect phasing across the crossing. Additionally, the height difference between the old and new poles made verifying phasing challenging, as standard Bluetooth and wired phasing meters were not viable due to distance and safety concerns.

To ensure correct phasing and prevent electrical equipment damage, Think Power Solutions took proactive steps to identify and correct the phase misalignment before finalizing the underground feeder circuit:

• Thorough Inspection & Verification: Conducted a detailed review of phase markings before requesting PD testing, identifying a mismatch between conductors on opposite sides of I-45.
• Immediate Correction: Contacted the underground foreman and coordinated a phase swap on one of the risers to align with the existing circuit.
• Innovative Phasing Solution: Collaborated with Oncor’s DOT to install an air break switch east and south of the crossing.

This approach:

• Allowed for an outage window to safely drop and reconfigure the highway crossing.
• Reduced customer impact during the transition.
• Enabled accurate phasing at the new switch location.

This project showcased Think Power Solutions’ expertise in power system oversight and proactive problem-solving. By taking the initiative to inspect, verify, and correct potential issues before final energization, we ensured a smooth transition from overhead to underground while maintaining correct phasing and minimizing customer impact.

At Think Power Solutions, we deliver solutions that prevent issues before they arise, ensuring power reliability and safety.

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Though the project is still ongoing due to crew availability constraints, the implemented solution ensured accurate phasing and prevented potential damage to electrical equipment from incorrect rotation.

• Prevented Equipment Damage: Identified and corrected phasing before energization, avoiding costly failures.
• Innovative Problem-Solving: Developed a custom phasing verification method despite height differences between poles.
• Reduced Service Disruptions: The air break switch solution allowed for a controlled outage, reducing service disruptions and minimizing the customer impact.
• Enhanced Grid Reliability: Replacing the overhead crossing with underground infrastructure improved safety and system resilience.