What FAT and SAT are and when you need them
FAT and SAT are the two acceptance stages of an electrical system. The FAT (Factory Acceptance Test) is carried out at the factory or the integrator’s workshop, before shipment, and shows that the equipment or panel meets the specification. The SAT (Site Acceptance Test) is carried out on site, with the equipment installed and connected, and shows that it works with the real yard equipment, the grid and the control center.
They apply to control and protection panels, substation automation systems, gateways, medium voltage switchgear and transformers, in substations and in industry. A good FAT–SAT pair shortens the time on site: what is corrected at the factory is not corrected in the yard.
What is included
What the FAT verifies:
- Visual inspection, dimensions, nameplates, labels and conformity with the approved drawings.
- Point-to-point wiring against the schematics, and wiring insulation.
- Model, firmware and settings loaded in each relay and IED.
- Protection functions by secondary injection, and the trip, blocking and interlocking logic.
- Communications: IEC 61850 GOOSE and MMS, gateway and signals to SCADA, with simulators where real equipment is not available.
- Local operator interface and alarms.
- Manufacturer’s routine tests on primary equipment, according to its standard.
What the SAT verifies:
- Condition of the equipment after transport and installation.
- Field wiring between the yard, the panels and the auxiliary services.
- Real current and voltage circuits, with correct connection and polarity all the way to the relay.
- Primary tests on the yard equipment.
- Protection functions with the final settings and real tripping of each circuit breaker.
- Interlocks with real disconnectors and circuit breakers.
- Point-to-point signals with the control center, and time synchronization.
- In solar plants, DC field tests (I-V curve, insulation, polarity, Voc and Isc) and thermography, from the ground on panels and stations and by drone in the photovoltaic field.
- Substation and BESS batteries: capacity or discharge, impedance or conductance and cell voltage.
- MV and LV cables after laying and, if a test fails, fault location so that only the affected section is repaired.
- Items left open at the FAT.
How we work: a typical protocol
- Protocol review. We check the protocol against the specification, the approved drawings and the settings from the study. Every test must have an acceptance criterion and a space for the measured value.
- Preparation. We verify that test equipment is calibrated, that drawings are the latest revision and that simulators are available for what is not at the factory. Based on your case, we recommend the right tests and equipment and include them in the quote, so you get the tests your project really needs and do not pay for extras.
- FAT execution. We inject with the Omicron CMC 356, check the wiring, test logic and communications and record every deviation.
- FAT close-out. We close the report with the open items and their owner. Shipment is authorized when the critical items are closed.
- SAT execution. Primary tests with calibrated test equipment where applicable, secondary tests with final settings, end-to-end functional tests and tests with the control center.
- SAT close-out. Final report, an open-items list at zero or accepted by the client, and documentation ready for energization.
Criteria and standards in FAT and SAT
IEC 62381 describes the FAT, SIT and SAT stages for automation systems. IEC 61850-4 covers project management of substation automation, including acceptance testing, and each IED’s conformance to the standard is declared by the manufacturer under IEC 61850-10. For primary equipment, factory routine tests are set by the standard of each device, for example IEC 62271-200 for medium voltage switchgear and IEC 60076-1 for power transformers.
Acceptance criteria come from the project specification, the approved drawings, the settings study and the manufacturer’s values. For protection, we check that each function operates within the tolerance declared by the manufacturer for the approved setting, following the project’s protection setting criteria. For equipment such as GIS, on-site tests also include those specific to the equipment, such as circuit breaker operating time tests.
What you receive
- FAT and SAT protocols reviewed or written according to the scope.
- FAT and SAT reports with measured values, criteria and the result of each test.
- List of deviations and open items, with owner and closing date.
- Backup of the settings and configurations loaded at the end of the SAT.
- Drawings marked up with the changes made at the factory or on site.
Why Tiza Group
- One team accountable from start to finish, from the FAT to energization, with the same open-items list.
- Field judgment from design through commissioning, in medium, high and extra-high voltage.
- Experience with the main brands: Siemens, Schneider Electric, SEL, ABB, GE, Fanox, NOJA Power and Efacec.
- Test equipment from recognized manufacturers (OMICRON, Doble, Baur, among others) for primary and secondary tests.
Field work is done in Colombia, or elsewhere on request, or by your local crew with our online support. Contact us to plan your FAT and SAT.