MV/HV Electrical Substations
Construction, Rehabilitation, and Major Maintenance
Complete EPC engineering for medium- and high-voltage substations: design, equipment supply, installation, acceptance testing, and energization. From 13.8 kV to 115 kV in Mexico.
Electrical substation services
We cover the complete life cycle: from conceptual engineering to periodic major maintenance.
EPC construction
Conceptual and detailed design, supply of transformers, breakers, switchgear, and bus, civil works, electromechanical installation, FAT/SAT testing, and turnkey energization.
Rehabilitation and expansion
Replacement of breakers, disconnect switches, and transformers. Operating capacity expansion. Upgrade of protection and control systems (SEL and ABB REF numerical relays).
Major maintenance
Preventive and corrective maintenance: primary electrical testing, VLF, thermographic inspection, breaker cleaning and adjustment, protective relay calibration, and protection coordination.
Electrical acceptance testing
TTR (turns ratio), winding resistance, dielectric strength, no-load and load losses, VLF on MV and HV cables, short-circuit impedance test.
Synchronizing switchgear and interlocks
Design and installation of synchronizing switchgear for cogeneration systems and power plants. Safety interlocks and mechanical and electrical interlocking for shared substations.
ALS / SF₆ circuit breakers
Supply, installation, and rehabilitation of SF₆ high-voltage breakers (ALS 5315, ALS 56-235) for CFE Transmission and industrial substations. SF₆ refilling and testing.
Substations we have built and maintained
Industrial substations, offshore platforms, sugar mills, and switchgear rehabilitation for CFE Transmission.
Grupo PIASA
San Luis Potosí and Veracruz, Mexico
Substation construction. Medium-voltage electrical engineering to connect the substation to switchgear and MCCs at the Tres Valles and Adolfo López Mateos sugar mills.
CFE Transmission
Jalisco, Mexico
Supply and installation of spare parts to rehabilitate the metal-clad switchgear tie sections with ALS 5315 and ALS 56-235 breakers.
Cement plant
Jalisco, Mexico
Major maintenance of a 69 kV substation.
Tres Valles sugar mill
Veracruz, Mexico
Supply and startup of materials to increase the operating capacity of 4,160 V substations no. 2 and no. 5, with electrical testing.
MALOOB-D and ZAAP-E platforms — Pemex
Campeche, Mexico (offshore)
Electrical testing and startup of substations comprising metal-clad distribution switchgear, 1,500 and 1,000 kVA transformers, and uninterruptible power systems.
BALAM platform — Cotemar
Campeche, Mexico (offshore)
Complete VLF electrical testing of the sectionalizer’s primary and secondary circuits, and diagnosis of the 1,500 kVA transformer.
Adolfo López Mateos sugar mill
Oaxaca, Mexico
Engineering, supply, and startup of the cogeneration synchronizing panel, with MSLC II and DECS 250 units in the control board.
Campeche Litoral-A — Pemex
Campeche, Mexico (offshore)
Supply, installation, and testing of the 800 A, 4,160 V metal-clad Siemens main breaker feeding a 1,500 kVA, 4,160/480 V cast-resin transformer.
Bottling plant
Colima, Mexico
Maintenance of a substation, four transformers, and low-voltage distribution switchgear, with thermography, megger testing of wiring, and breaker operation tests.
EPC execution process
Engineering and design
Field survey, short-circuit study, protection coordination, single-line diagrams, calculation reports, and equipment specifications.
Equipment supply
Transformers, SF₆ or vacuum breakers, MV switchgear, bus, control and protection panels. FAT follow-up at the factory.
Construction and installation
Civil works (foundations, oil containment), electromechanical installation, control and instrumentation wiring, and grounding.
Testing and commissioning
SAT per NETA MTS: TTR, resistance, VLF, dielectric strength, relay calibration, functional testing, and operational handover to the client.
Acceptance and diagnostic tests we perform
IEEE C57.12 / IEC 60076
TTR — Turns Ratio
Verifies the rated turns ratio and winding polarity on every tap of the DETC/OLTC.
NETA MTS / IEC 60076
Winding resistance
Detects loose joints, broken conductors, or thermal deterioration in windings. Measured with a Kelvin bridge or micro-ohmmeter.
IEEE 400.2 / IEC 60502
VLF — Very Low Frequency
0.1 Hz dielectric test on MV cables. Detects XLPE insulation deterioration without the destructive risk of DC testing.
IEC 60076-1 §11.5
Dielectric strength (hipot)
Voltage applied for 1 minute to verify the integrity of the main and phase-to-phase insulation.
ANSI/NETA MTS
Contact resistance
Measurement of main circuit resistance in breakers and disconnect switches to detect burnt or loose contacts.
IEC 62271 / ANSI C37
Opening/closing time
Verification of SF₆ and vacuum breaker operating times with a trip circuit analyzer.
Substation components we supply
VMS Energy works with leading manufacturers to supply every component of a complete LV/MV substation, from switchgear to protection instrumentation.
✓ = service available | Other manufacturers available per client specification.
Standards we apply to substations
High-voltage switchgear. General and specific requirements for MV/HV breakers, disconnect switches, and metal-enclosed switchgear.
Power transformers. Complete series: general requirements, temperature rise, insulation, short circuit, and dry-type transformers.
Electrical installations in Mexico. National reference for the design, installation, and operation of substations and service entrances.
Maintenance Testing Specifications. Internationally accepted test procedures for acceptance and maintenance of medium- and high-voltage equipment.
Standard for Transformers. Performance and test requirements for distribution and power transformers in North America.
CFE specifications. Requirements for equipment supply and installation at CFE Transmission and Distribution facilities.
Common questions about electrical substations
What does major substation maintenance include?
What is VLF testing in substations?
Does VMS Energy build substations from scratch?
What voltage levels do you work with?
Count on substation experts!
From conceptual engineering to energization, with experience in Oil & Gas, industry, and utilities.
Need FQ/DGA oil analysis?
VMS Energy performs complete dielectric oil diagnostics: BDV dielectric strength, moisture, acidity, DGA by chromatography, and Duval triangle, per IEC 60422 and IEEE C57.104.
See dielectric oil analysis service → ES