Testing, commissioning, and startup: nothing is energized until it has been tested
We plan, perform, and document pre-operational electrical testing, controlled energization, and performance testing for transformers, switchgear, MCCs, medium-voltage cables, protection, variable frequency drives, and generation systems. You get the equipment running and the dossier that proves it.
The most expensive moment to find a fault is first energization
At the end of a project, the pressure is to start up. That is exactly when tests get skipped, factory settings get accepted, and equipment is handed over without evidence. These are the situations we see most:
Undetected shipping or installation damage
Equipment that passed its factory test can arrive with moisture, impact damage, or a loose connection. Without site testing, the damage shows up at energization.
Protection left at generic settings
Relays and breakers shipped with factory values instead of the settings from the coordination study: nuisance trips or, worse, protection that does not trip.
Several vendors, no one integrates
Switchgear from one vendor, the transformer from another, and the drive from a third. Each one tests its own equipment; no one tests the complete system working together.
Handover without evidence
Without signed protocols or reference values, warranty claims get harder and maintenance starts with no baseline to compare against.
One sequence, two release points
Commissioning is not a test at the end: it is a sequence that starts before the equipment reaches the site. Nothing is energized without release from pre-operational testing, and nothing is handed over without accepted performance tests.
Commissioning plan and protocols
We define what is tested, with what method, against which acceptance criteria, and who witnesses. It is agreed before construction, not during startup.
FAT witnessing
We attend factory acceptance tests for transformers, MCCs, sectionalizers, and drives to confirm the equipment meets its datasheet before it ships.
Site receipt and inspection
Check of shipping condition, nameplate data, visible damage, and installation and interconnection conditions before any electrical test.
Pre-operational electrical testing (SAT)
With the equipment de-energized: insulation, turns ratio, resistance, control wiring verification, protection settings and trip tests, interlocks.
Release for energizationControlled energization and startup
Staged energization with scheduled switching, voltage and phase-sequence checks, and no-load behavior; configuration and startup of drives, generation, and control.
Functional and performance testing
Operation under real load: transfers, synchronization, control loops and communication with SCADA or DCS, and punch-list closeout with the client.
Client acceptanceThe seventh stage, handover to operations, is described under deliverables. For technical detail on each transformer test, see our guides to FAT and SAT testingES and transformer installation and commissioningES.
From the transformer to the control loop
We test the equipment and, above all, the system: how the transformer works with its switchgear, its protection, its backup, and its controls.
| Equipment or system | Typical tests and checks |
|---|---|
| Power and distribution transformers | Insulation resistance and polarization index, winding resistance, turns ratio (TTR), power factor, running and performance tests. Dielectric oil analysisES where applicable.Reference: IEC 60076, IEEE C57.12.91 |
| Medium-voltage cables and accessories | Insulation resistance, VLF testing of primary and secondary circuits, hipot on terminations and stress cones, verification of splices and premolded elbows.Reference: IEEE 400.2 |
| MV/LV switchgear, sectionalizers, and MCCs | Pre-operational testing of bus and breakers, breaker operation, interlocks and control wiring, automatic transfers, Profibus or Modbus communication. See medium-voltage switchgearES and MCCsES.Reference: IEC 61439, IEC 62271-200 |
| Electrical protection | Verification of settings against the protection coordination studyES and trip testing of relays and breakers. |
| MV and LV variable frequency drives | Installation, interconnection, configuration, functional testing, startup, and performance testing with the motor and the process. See variable frequency drivesES. |
| Generation, synchronization, and governors | Commissioning of speed governors, synchronizers, and load control; synchronization with the utility grid, import and export. See turbine generators. |
| UPS, batteries, and backup | Pre-operational testing, startup, and performance testing of UPS units, chargers, and battery banks, including transfer of critical loads. |
| Control, automation, and communications | Interconnection and pre-operational testing of PLC, DCS, and SCADA; verification of process signals and communication (Profibus, Profinet, Modbus). |
| Grounding systems | Ground grid resistance measurement and continuity of equipment bonding. |
The standards listed are for reference; each project’s protocol is defined with the client, the project specification, the applicable local electrical code (NOM-001-SEDE in Mexico), and each manufacturer’s recommendations.
Equipment in operation, and the evidence that it was tested
The commissioning dossier is the baseline for your maintenance: the values every future test will be compared against.
- Plan and protocolsScope, method, and acceptance criteria for each test, agreed before work starts.
- Test recordsMeasured values, test conditions, and the result for each piece of equipment, signed by the witness.
- Applied settingsFinal protection, drive, and control settings exactly as left on site.
- Punch listOpen items with owners and documented closeout of each observation.
- Handover dossierComplete commissioning file for operations, maintenance, and warranty.
- Knowledge transferWalkthrough of operation and maintenance for your team. See trainingES.
Commissioning on offshore platforms, in generation, and in industry
Much of our work includes pre-operational testing, startup, and performance testing, from platforms in the Campeche Sound to sugar mills and mines. Some examples:
Pemex · Maloob A platform
Campeche Sound, Mexico
Pre-operational electrical testing, startup, and performance testing of metal-enclosed distribution switchgear and a motor control center.
Pemex · EK-A platform
Campeche Sound, Mexico
FAT, installation, functional testing, startup, and performance testing of a 7.5 MVA transformer and a nine-way 34.5 kV sectionalizer.
Pemex · Balam-A platform
Campeche Sound, Mexico
Primary electrical testing of 12 transformers (6 phase-shifting and 6 step-up) and of 34.5 kV distribution transformers.
CFE · Chankanaab power plant
Cozumel, Quintana Roo, Mexico
Engineering, supply, installation, and startup of AC and DC motor control centers.
SLB
Tabasco, Mexico
Engineering, supply, installation, and startup of two 1,000 HP medium-voltage drives and 4.16 kV distribution switchgear.
Baker Hughes
Campeche, Mexico
Supply, installation, and startup of 14 variable frequency drives in outdoor enclosures.
Ingenio San Nicolás (sugar mill)
Veracruz, Mexico
Commissioning of the new power plant’s distribution switchgear, with utility (CFE) synchronization, import, and export.
Infrastructure · Road tunnel
State of Mexico · 2025
Integration and commissioning of 12 VFD cabinets with Profinet control via SCADA for ventilation and extraction.
As part of our EPC, or as the commissioning contractor on your project
Commissioning can be a stage of our own project or a standalone service for equipment you already bought or another contractor installed.
As part of an EPC project
When VMS designs, supplies, and installs, commissioning is planned from engineering onward and closes with a single party responsible for the whole system.
For third-party equipment or contractors
We test and put into service equipment that others supplied or installed, from any brand, and integrate equipment from several vendors into one working system.
After a retrofit, expansion, or failure
Testing and re-energization after a retrofitES, a capacity increase, or a repair, so you return to operation with evidence instead of trial and error.
Operations where a failed startup is expensive
Where the startup window is short and a delay or a failure at first energization is measured in lost production.
Oil & Gas
Offshore platforms and onshore facilities, with short work windows and complex logistics. See Oil & Gas solutions and maintenance.
Generation and cogeneration
Sugar mills, paper mills, and power plants with turbine generators, utility synchronization, and generation control.
Mining, manufacturing, and infrastructure
Substations, MCCs, VFD-driven pumping, and ventilation systems where every day of startup delay stops production. See miningES.
Frequently asked questions
What is the difference between testing, commissioning, and startup?
Can you commission equipment you did not supply or install?
Do you witness factory acceptance tests (FAT)?
What happens if a test does not meet the acceptance criteria?
What do you deliver at the end of commissioning?
Do you work offshore and outside Mexico?
Startup coming up?
Tell us which equipment you are putting into service and where your project stands. We will propose a testing and commissioning plan with scope, schedule, and deliverables.