San Lorenzo, Puerto Rico – September 25, 2025 – As part of a scheduled maintenance plan for substations in the southeastern region of the island, LUMA is carrying out a series of essential tasks in Humacao and San Lorenzo, benefiting more than 14,000 customers in the area. These efforts are part of infrastructure modernization initiatives aimed at improving the safety, performance, and reliability of the electrical system.
Improvements at the San Lorenzo Substation
Since mid-August, crews have been working on various pieces of equipment at the substation, which serves over 7,000 customers, including:
- Major maintenance on the transformer: This equipment reached the end of its 11-year lifecycle and underwent testing and adjustments to extend its reliability. This included correcting oil leaks to prevent failures and environmental damage.
- Installation of additional fans on circuits to improve ventilation and prevent overheating in the substation’s electrical system.
- Maintenance of the transformer’s voltage regulator (Load Tap Changer or LTC): A critical component that regulates the voltage customers receive and minimizes fluctuations. This equipment requires maintenance every four years to ensure optimal performance and support continuous transformer operation.
- Installation of three insulators to reduce the risk of faults on the lines.
To carry out the transformer work, a portable substation was installed, allowing customers to remain in service while repairs were completed—part of the company’s commitment to minimizing service interruptions during planned upgrades.
The crews have since removed the portable substation and successfully returned the main transformer to service after it passed load testing.
Proactive Work at the Humacao Pueblo Substation
Since last week, work has been underway on critical equipment with over 25 years of use, including:
- Replacement of the battery charger for the protection system: This equipment powers the protection relays that detect faults and protect the substation from potential failures.
- Upgrade of the control house distribution panel: Circuit identification was improved, and proper lighting was ensured for safe working conditions.
Additionally, on October 1, from approximately 6:00 p.m. to 6:00 p.m., scheduled work at the substation included:
- Replacement of busbar supports: Key components that hold the main substation busbar, which carries electric service to customers.
- Correction of control cables on transmission line 12,500.
- Additional inspections to ensure equipment operates according to industry standards.
“Each of these tasks—from equipment replacement to control system upgrades—has a direct impact on service stability for customers in Humacao and San Lorenzo. Our commitment is to continue strengthening the electric grid through preventive maintenance and planned improvements,” said José Hernández, Substation Supervisor for the Eastern Region.
LUMA is carrying out these planned improvements in coordination with municipalities and in compliance with strict safety measures and the highest industry standards. Specific areas that may be affected are listed on the Planned Improvements Portal.
These efforts are part of LUMA’s island-wide reconstruction and transformation projects aimed at strengthening critical infrastructure and improving the system’s emergency response. However, LUMA has repeatedly emphasized that to continue these critical initiatives, it is essential to have the necessary funds in the appropriate accounts to maintain the pace of work and the transformation of Puerto Rico’s electric grid.
About LUMA
LUMA is a Puerto Rican company that, since June 1, 2021, has operated and managed the electric power transmission and distribution system in Puerto Rico. LUMA is a mission-driven company focused on transforming the transmission and distribution system to provide all Puerto Ricans with the reliable, resilient, clean, and affordable electric grid they deserve. As a customer-focused company, LUMA’s entire workforce of over 4,500 employees is committed to delivering an exceptional customer service experience to its 1.5 million customers.
