FAT proves that equipment can perform in the agreed factory configuration. SAT proves that the installed system works with real fuel, ventilation, distribution, controls and loads. Neither replaces the other, and a few running photos are not an evidence package.
What the acceptance plan must produce
Owners, EPC teams, suppliers and site teams responsible for procurement, inspection, installation, commissioning and acceptance.
Turn specification clauses into observable, measurable, signable and traceable FAT and SAT items.
Produce procedures, acceptance criteria, instruments, responsibilities, raw records, punch lists and closeout evidence.
Freeze the acceptance matrix before manufacture. Put configuration, wiring, controls, protection and factory-testable performance in FAT; put installation, fuel, ventilation, earthing, upstream distribution and real interfaces in SAT. Every item needs acceptance criteria and evidence.
01
Convert the specification into an acceptance matrix
Do not define acceptance after equipment is complete. Map the single-line, data sheets, control narrative, protection settings, communications and deliverables to FAT, SAT or document review.
- State requirement source and acceptance criteria
- Assign witness, review and signature responsibility
- Record instrument identity, accuracy and calibration
02
Use FAT for build configuration and standalone functions
Confirm nameplates, components, assembly, wiring, insulation, logic, alarms, trips, protection, synchronization, paralleling and agreed load performance. Transfer unrepresentative site conditions to SAT explicitly.
- Verify engine, alternator, controller and switchgear
- Test circuits, terminals, interlocks, alarms and emergency stop
- Record voltage, frequency, load and temperature trends
03
Control punch items before release
Each finding needs identity, consequence, owner and due date. Safety, configuration or core-function issues block release; site-close items require an agreed condition and verification method.
- Retain issue photos, data and repair record
- Separate release blockers and site actions
- Freeze drawing and software versions before packing
04
Use SAT for installation and system interfaces
Verify foundation, vibration, exhaust, ventilation, fuel, earthing, cables, phase sequence, protection, communications and upstream distribution. Starting a standalone unit does not prove system readiness.
- Check dimensions, torque, fluids, leaks and clearances
- Test ATS, paralleling, shedding and remote signals
- Apply staged site load and record stability
05
Handover a complete evidence package
Include approved procedures, raw data, signatures, alarms and trends, punch closeout, as-builts, settings, software backup, training and maintenance baseline.
- Index FAT, SAT and outstanding items
- Confirm as-builts match the field
- Have owner, EPC and supplier sign the responsibility boundary
FAT and SAT evidence matrix
| Test item | Requirement source, FAT/SAT location and procedure |
|---|---|
| Acceptance | Value, state, action time or document completeness |
| Conditions | Load, environment, fuel, system state and prerequisites |
| Instrument and people | Instrument, calibration, operator, witness and signature |
| Raw evidence | Readings, trends, alarms, photos, video and record |
| Closeout | Item, grade, owner, date and verification evidence |
Three acceptance gaps
FAT limited to appearance and start
Controls, protection, paralleling and load risk move to site untested.
Using FAT instead of SAT
Factory tests cannot prove site ventilation, earthing, fuel, distribution and interfaces.
Summary result without raw records
Without data, version and signatures, acceptance is not traceable.
Information required before test notice
- Specification, data sheets and approved drawings are frozen
- The matrix covers every system and interface
- Each item has criteria, instrument and owner
- Load bank and site-load arrangements are confirmed
- Punch grading, release and closure rules are approved
- As-builts, training and maintenance baseline are in handover