Medium and High-Voltage Electrical Services
All around medium and high-voltage expertise for your critical infrastructure

For your high-power distribution projects, Entreprise Électrique MJL acts as your single point of responsibility. In close partnership with the specialists at Ligne STE, we provide complete management of the design, installation, and maintenance of your private networks throughout Quebec.

Our teams have the skills, accreditations, and equipment required to ensure safe, compliant, and durable interventions, even in the most demanding environments.

Our approach

Solid expertise for your high-power electrical networks

Medium and high-voltage networks are at the heart of industrial, municipal, and institutional infrastructure.

Supported by the MJL Systèmes Automation and Ligne STE divisions, our team has the skills, accreditations, and equipment required to ensure safe, compliant, and durable interventions, even in the most demanding environments.

MJL Électrique technician performing a medium and high voltage intervention on power network equipment
Our services

Comprehensive medium and high-voltage services

Our technicians are trained to intervene across the entire lifecycle of your high-power electrical installations:

Construction of overhead and underground networks

We handle the complete deployment of your distribution infrastructure. This includes the construction of private electrical lines, pole installation for overhead networks, as well as excavation and installation of underground distribution systems. Our partner ensures a durable structure adapted to your site’s topography.

From procurement to energization, we manage the installation of your transformers (available for purchase or rental) and metering enclosures for accurate consumption readings. We also ensure the safe integration of all switching gear and substations required for your power supply.

The reliability of your network depends on the quality of its connections. Our experts perform certified installation of medium-voltage cable terminations and complex terminations. These connections are executed with precision to ensure junction safety and prevent premature failure of critical equipment.

To ensure the longevity of your installations, we offer a comprehensive inspection and maintenance service, including the use of 55-foot bucket trucks for work at height. In the event of an outage, our 24/7 emergency service enables rapid intervention to diagnose, repair, and restore power—minimizing operational losses.

Installation et mise en service d’équipements moyenne et haute tension

Transformateurs, disjoncteurs, sectionneurs, appareillage de commutation, sous-stations et postes électriques.

Assemblage, pose et test de têtes de câbles moyenne tension selon les standards de l’industrie (3M, Nexans, Raychem, etc.)

Vérification des composantes, mesures d’isolation et tests de performance pour garantir la fiabilité et la sécurité de vos réseaux.

Mise à niveau d’infrastructures électriques selon les réglementations CSA et Hydro-Québec, pour prolonger la durée de vie de vos installations.

Détection de défauts, entretien planifié, thermographie infrarouge et analyse d’onde électrique pour prévenir les pannes coûteuses.

Notre approche

Sécurité, conformité et fiabilité avant tout

Les travaux en moyenne et haute tension nécessitent une expertise pointue et une discipline rigoureuse.
Nos équipes appliquent des protocoles de sécurité stricts et utilisent des équipements certifiés afin d’assurer des interventions sans risque et conformes aux exigences du Code canadien de l’électricité.

Nous garantissons :

  • Des procédures normalisées et documentées

  • Des tests de continuité, de résistance et d’isolation systématiques

  • Une traçabilité complète des opérations et des rapports techniques

  • Une collaboration constante avec les ingénieurs et fournisseurs d’équipement

Chaque projet est planifié et exécuté pour assurer performance, fiabilité et durabilité des infrastructures électriques à long terme.

About us

An alliance of experts for your critical infrastructure

Through close collaboration with its strategic partners, Entreprise Électrique MJL delivers a uniquely integrated expertise in Quebec.

This synergy allows us to provide a turnkey service, from the power source to the control system, with a high level of precision and safety.

Entreprise Électrique MJL

Project management, design, and installation of main electrical distribution systems.

MJL Systèmes Automation

Design and integration of control, instrumentation, and communication systems for energy management.

Ligne STE

Construction, connection, and critical maintenance of medium and high-voltage infrastructure (overhead and underground networks).

Trust Entreprise Électrique MJL

Do you have a medium or high-voltage electrical project?

Whether it’s a medium-voltage connection, the construction of an electrical substation, or the maintenance of high-voltage lines, Entreprise Électrique MJL provides comprehensive and responsive support. We work on your critical infrastructure in the industrial, municipal, and energy sectors, with an unwavering commitment to the safety and performance of your power distribution.