Service · Factory execution · FAT
Generator FAT witnessing in China
- What you get:
- A factory acceptance test (FAT) witness in China records measured results and deviations for the buyer’s release decision.
- Turnaround:
- Scope and price within two business days of a sufficient file; signed report within two working days of the last test day on a single-equipment FAT.
- Price:
- USD 1,280–3,600 all-in, as one fixed price per job before you book.
For a diesel generating set you buy directly from a Chinese assembler, Sinospect sends a named inspector or engineer to witness the factory acceptance test on the plant's test bay. The person attending checks the engine, alternator and controller against your order, then witnesses the load test in steps up to full load and the overload your contract names, the transient response, and the protections and shutdowns. The person attending signs a witness report with every reading, every deviation and a release, hold or retest recommendation, and you keep the release decision. When Sinospect supplies the set itself, you receive the factory load-test record and its inspection report before the balance, a test witnessed by its engineer can be added as supplier-side quality control, and any independent or accredited witness your contract requires is appointed separately.
- Equipment class
- Diesel generating sets, open, canopied and containerised, prime or standby
- Test basis
- The agreed FAT programme, ISO 8528-6 test methods, the ISO 8528-5 performance class the contract names, and your purchase specification
- Where it runs
- Generating-set assembly plants and their test bays across China
- Typical duration
- One witness day for a single set; a containerised set, several sets or a long full-load run add days
- Engagement output
- Buyer-direct: signed independent witness record; supplied order: factory load-test record and Sinospect's inspection report, with a witnessed test on request. Both include a non-conformity log and release recommendation
Quick answers
What does generator FAT witnessing in China cover?
For a generating set you buy directly from a Chinese assembler, Sinospect's inspector or engineer attends the FAT and checks the set against your order. The person attending records the engine, alternator and controller identity, witnesses the load test in steps up to full load and the overload the contract names, checks the protections and the controller, and reviews the documents. That person then signs a witness record, and you keep the release decision. When Sinospect supplies the set, you receive the factory load-test record and its inspection report before you pay the balance; a test witnessed by its engineer can be added to the order as supplier-side quality control. Any independent or accredited witness your contract requires is appointed separately, and your acceptance authority stays as the contract states.
| Stage | What is witnessed | Acceptance basis |
|---|---|---|
| Identity and build | Engine, alternator and controller dataplates and serial numbers, rating, fuel tank, radiator, canopy or container, wiring and labels | Purchase order, datasheet and approved drawings |
| Pre-start checks | Alternator insulation resistance, fluid levels and leaks, battery and charger, earthing, emergency stop | FAT programme and maker's procedures |
| Load test | Steps to 100% of prime power and the overload step, each held until stable: voltage, frequency, current, kW, kVA, power factor, coolant and oil readings | ISO 8528-6 test methods and the ratings on the datasheet |
| Transient response | Sudden load acceptance and rejection: voltage and frequency dip, overshoot and recovery time | ISO 8528-5 performance class (G1 to G4) named in the contract |
| Protections and controller | Low oil pressure, high coolant temperature, overspeed, emergency stop, alarms, remote start, transfer-switch signals, synchronising where ordered | FAT programme and controller configuration |
| Documentation | Test record, engine and alternator certificates, wiring diagrams, manuals, spare-parts list | Contract document list |
What does the generator FAT witness report contain?
A signed report tied to the serial numbers of the sets tested: what was tested, against which limits, with which load bank and instruments, what failed and what the person attending recommends. The sample witness checklist (PDF) at the top of this page is the sheet filled in on the test bay.
| Section | What it records | Convention |
|---|---|---|
| Set identity | Engine, alternator and controller dataplates, serial numbers and manufacturing dates, with photos | Every reading is linked to a set on your order |
| Test basis | Purchase specification, FAT programme, ISO 8528 parts, performance class, load bank type and power factor | Agreed before the visit |
| Load-step readings | Voltage, frequency, current, kW, kVA, power factor, coolant and oil readings at each step, with the time held | PASS, FAIL or NA (not applicable) for each scheduled step |
| Non-conformities | Deviation, requirement reference, plant response and witnessed retest | Open until closed or accepted by the buyer |
| Documents reviewed | Test record, engine and alternator certificates, diagrams, manuals and spare-parts list | Gaps listed with the party who owes them |
| Recommendation | Release, conditional release, hold or retest, signed by the person who attended | The buyer decides under the contract |
Why witness a generator FAT when the plant issues a test record?
Because a set that fails at site costs a crane, a technician's flight and the days without power it was bought to prevent. A plant's test record states results; it does not show which set was on the bay, what power factor the load bank ran at, or what was adjusted between a failed run and the final printout. Witnessing ties the readings to the serial numbers on your order while the set is still at the plant, when a correction is cheapest.
| Question | Test record only | Witnessed FAT |
|---|---|---|
| Was the exact set on your order tested? | Stated by the plant | Engine, alternator and controller serials recorded on the bay |
| At what power factor did the load bank run? | Rarely stated | Load bank type, capacity and power factor recorded |
| What happened on failed runs? | Often the final result only | Non-conformities logged with the plant's response and witnessed retest |
| Is there a release basis before dispatch? | Depends on your contract and what the record shows | Signed witness record with a release, hold or retest recommendation |
01 · Scope
When generator FAT witnessing is the right control
A generating set is bought to run when everything else has failed, so its first real test should not be the day the grid goes down. At the plant, a load bank, the plant's technicians and spare parts are all at hand; at site, the same fault means a flown-in technician and days without power. Witnessing fits a buyer-direct order when the set is critical, the contract names a load test or performance class, or your engineers cannot travel to China. For small sets bought in numbers, a pre-shipment inspection with a short run test is often the lighter control that fits.
It becomes useful when
- The set is the only backup for a plant, a hospital, a data room or a site with no grid, and a failure at start-up would stop operations.
- The contract names a load test, an overload step, a performance class or guaranteed fuel consumption that must be shown before release.
- The set is containerised or synchronised with others, so ventilation, exhaust, controllers and paralleling all need checking before shipment.
- The offer names a branded engine or alternator, and you want the dataplates and serial numbers checked against the order.
- Your engineers cannot travel to China for the test, or attend the first set of an order at most.
- Payment or shipment is due on the plant's own test record, and the order value makes that unacceptable.
02 · Controls and evidence
What the witness controls on the test bay
Control point
Test programme, load bank and readiness
Purchase specification, agreed FAT programme, load bank type, capacity and power factor, instrument list and calibration references confirmed before the visit, with the load steps, hold times and overload step stated for the buyer's review.
Control point
Set identity and build against the order
Engine, alternator and controller dataplates, serial numbers and manufacturing dates; rating; radiator, fuel tank, canopy or container, cabling, labels and earthing checked against the purchase order and drawings before the set is started.
Control point
Load test witnessed step by step
Each load step held until the readings settle, with voltage, frequency, current, kW, kVA and power factor, coolant temperature and oil pressure recorded against the datasheet, then the full-load period and the overload step the contract names.
Control point
Transient response where a class is guaranteed
Sudden load acceptance and rejection with the voltage and frequency dip, overshoot and recovery time recorded against the ISO 8528-5 performance class in the contract, in load steps the engine can take.
Control point
Protections, controller and documents
Shutdowns and alarms triggered and recorded (low oil pressure, high coolant temperature, overspeed, emergency stop), controller functions such as remote start, transfer-switch signals and synchronising exercised where ordered; certificates, diagrams and manuals reviewed while the set is still at the plant.
Evidence reviewed
Evidence captured during the witnessed FAT
- Test basis and readiness record
- Purchase order, datasheet, approved drawings, FAT programme and acceptance criteria checked before the witness event.
- Plant readiness confirmed: set complete, load bank booked with its capacity and power factor stated, instruments identified with calibration references.
- Load steps, hold times, overload step, transient tests and exclusions documented against the contract.
- Witnessed reading record
- Engine, alternator and controller dataplates photographed and tied to the test record.
- Readings at every load step recorded with the time held, the load bank setting and pass or fail against the limit.
- Shutdown tests, deviations and adjustments captured as they happen, with photo or video evidence.
- Disposition and release record
- Non-conformities logged with severity, requirement reference, plant response and target closure.
- Witnessed retest results and corrected documents captured where issues close before release.
- Release, conditional release, hold or retest recommendation prepared for the buyer's decision.
03 · Deliverables
Deliverables issued
Deliverable
For · Procurement and engineeringWitness plan and readiness note
The agreed witness scope, load programme, load bank and readiness status before the visit.
Deliverable
For · Engineering, project and external reviewersSigned generator FAT witness record
Readings at every load step, transient and protection results with limits and pass or fail status, tied to the engine, alternator and controller serial numbers.
Deliverable
For · Engineering and operationsPhoto and video evidence pack
Dataplates, instrument screens at each step, shutdown tests and any non-conformities, linked to the test record.
Deliverable
For · Procurement and the plantNon-conformity and retest log
Each failure or deviation classified, linked to its requirement, tracked through the plant's response, witnessed retest and closure.
Deliverable
For · Procurement and financeRelease recommendation
Release, conditional release, hold or retest: a practical recommendation for the contract-defined payment and dispatch decision, which the contract's acceptance authority then takes.
Booking your FAT
What you pay, who attends and what happens next
Sinospect takes a single FAT on an order you placed yourself. You do not need to buy anything else from us. Here is how the quotation is built and how the visit gets confirmed.
How this assignment is priced
Generator FAT
USD 1,280–3,600 all-in
One day on a single small set: our inspector, using the factory’s instruments. Up to two days with more to verify: our generator engineer, using their own instruments.
Your dated scope gives one fixed price before you book.
In an all-in quotation
- Review of the test plan against your specification before the visit
- Our inspector’s or engineer’s time on site, travel and lodging in China
- Measured values recorded and calibration certificates checked
- A signed English report with results, photographs and findings
- One review of the factory’s written answers to the findings in our report
Quoted separately, before it happens
- Days on site beyond those you booked
- A return visit or video re-test of a held unit
- Specialist instruments, where the test plan needs them
What moves the price
- The number of sets
- The hours at full load per set
- A reactive test at 0.8 PF
- Paralleling or synchronising tests
- The factory’s location
Before we confirm the visit
Within two business days
We acknowledge within one business day. When the file is sufficient, you get the scope, the quotation and the earliest date we can offer.
Before you book
You review the fixed price and the proposed inspector’s or engineer’s profile.
At booking
We confirm the person attending and the date in writing, with the invoice. Payment is due at booking.
Before travel
We check with the factory that the unit, the test bay and the calibrated instruments are ready.
On the test days
Findings are raised as they arise and go through at the closing meeting.
After the last test day
Your signed report within two working days.
How we choose who attends
- What we match
- Experience on the same class of equipment and the test methods in your plan.
- What you see
- The proposed inspector’s or engineer’s experience profile, before you book.
- Named approval
- Where your contract or consultant must approve a named person, we agree the credentials you need before you book.
- Who reviews
- Our quality desk reviews the report before it reaches you.
- If the person changes
- If the person proposed cannot attend or you do not accept the profile, you get another profile to approve before anyone travels.
If something moves
- The factory moves the date
- We rebook at no charge, subject to availability on the new date.
- The unit is not ready on the day
- The booked day stands and we record what we found. Any further day is quoted to you before anyone stays or returns.
- The test overruns
- We tell you the same day. Any extra day is quoted to you first and added once you agree.
- The test fails
- The finding goes in the report with the factory’s correction. A re-test, on site or by live video if you accept it, is quoted on the same basis.
04 · Risks controlled
Risks controlled
Risk
The engine or alternator fitted is not the make, model or production year the offer named.
Control response
Dataplates, serial numbers and manufacturing dates are recorded and photographed before the test, and checked against the order.
Risk
The set passes on a resistive load bank, and the alternator meets its first full reactive load at site.
Control response
The load bank's type and power factor are agreed before the visit and recorded in the report, so the buyer knows what was proven and what stays for the site test.
Risk
Voltage or frequency swings when a large motor starts, and the set trips or the load drops out.
Control response
Load acceptance and rejection are tested in agreed steps, with dip and recovery recorded against the performance class in the contract.
Risk
A shutdown is wired or set wrongly, and the engine runs on without oil pressure or overheats.
Control response
Each shutdown and alarm is triggered on the bay and its action recorded, before the set leaves the plant.
Risk
Diagrams, manuals or spare-parts lists are missing, and the site team cannot commission or maintain the set.
Control response
The document pack is reviewed while the set is still at the plant, and gaps are logged as open items with owners before release.
Risk
The buyer pays and releases on a verbal "all passed" and inherits the dispute after dispatch.
Control response
The signed witness record and release recommendation give the buyer a written basis to pay, hold or require a retest before the set leaves.
05 · Background resources
Related
- Service · Factory acceptance test in ChinaFAT scope, control points and deliverables.
- Resource · Buying diesel generating sets from ChinaRatings, what an offer must state, the factory test and shipping.
- Offer · Generating sets 50 to 275 kVAOpen-frame sets supplied on Sinospect's invoice, load-tested at the plant.
- Sector · Engine power packs for assemblersEngine, cooling and governing packages for the sets you assemble.
- Case study · Two 2 MVA generating sets for West AfricaEight inspections, a witnessed FAT from 25% to 110% load and the support after start-up.
- Service · Switchgear & panel FAT witnessingThe sibling scope for the transfer and synchronising panels around the set.
- Resource · Factory acceptance test checklistThe twelve-section FAT checklist, downloadable as a printable PDF.
- Sector · EnergyGenerating sets and the equipment around them, supplied from China.
06 · Questions
Frequently asked questions
Who can witness a generator FAT in China?
Four kinds of witness are common: the buyer's own engineers, the EPC contractor or owner's engineer, an accredited inspection body, or a technical witness hired for the test. On a generating set you buy directly from the assembler, Sinospect provides the last kind: from Hong Kong and Ningbo, it sends a named inspector or engineer to the test bay, and you receive that person's experience profile before booking. The person attending checks the set against your order, witnesses the load test and the protection checks, then signs a witness report with the readings. When Sinospect supplies the set itself, its checks are supplier-side quality control, not independent witnessing. Sinospect is not an ISO/IEC 17020 accredited inspection body: when your contract or lender requires an accredited certificate, an accredited body is appointed separately to issue it.
Which tests are witnessed during a generator FAT?
The tests in the agreed FAT programme. ISO 8528-6 describes the test methods for generating sets, and ISO 8528-5 the performance classes G1 to G4 that set the limits for voltage and frequency. A typical programme covers: identity of the engine, alternator and controller against the order; insulation resistance of the alternator windings; starting; voltage, frequency and phase sequence at no load; a load run in steps, often 25, 50, 75 and 100% of prime power, each held until the readings settle, with voltage, frequency, current, power, coolant and oil readings at every step; the overload step the contract names, often 110%; sudden load acceptance and rejection where a performance class is guaranteed; the shutdowns and alarms, such as low oil pressure, high coolant temperature, overspeed and emergency stop; and the controller functions the order includes, such as remote start, transfer-switch signals or synchronising. Fuel consumption and sound level are measured only where they are guaranteed.
Should the load test run at 0.8 power factor?
Ask before you book. A generating set is rated in kVA at 0.8 power factor lagging, so a 938 kVA set gives 750 kW. A purely resistive load bank works at a power factor of 1.0: it can load the engine to its full 750 kW, but the alternator then carries only about 80% of its rated current, and the alternator’s excitation is never pushed to the level a 0.8 power-factor site load demands. Many Chinese assembly plants have resistive load banks only. If the alternator's full-current performance matters to you, specify a resistive-reactive load bank at 0.8 power factor in the order. If the plant cannot provide one, agree in writing what the resistive test proves and what stays open for the site test.
How long does a generator FAT take?
For one set, plan a day: identity and pre-start checks, the load run in steps with each step held until the readings settle, a period at full load, the overload step, the transient tests and the protection checks. A containerised set adds checks on ventilation, exhaust, fuel and the container's own systems, and several sets or a long full-load run add days. Sinospect states the number of witness days in the quotation, based on the plant's test programme.
How do you check the engine is the one on the order?
Before the test starts, the person attending photographs and records the dataplates of the engine, the alternator and the controller: model, serial number, rating and manufacturing date. The engine serial number can be checked with the engine maker's service network, and the dataplate date shows whether a unit offered as new production is old stock. These records go in the report, so every reading on the test bay belongs to a serial number on your order.
What happens if the set fails a witnessed test?
The failure is recorded as a non-conformity with the reading, the limit and the plant's response. The plant proposes a correction, such as a governor or regulator setting, a replaced part or a rewired protection, and the test is repeated with our inspector or engineer present against the same criteria. That return is quoted to you before it happens. A major failure normally supports a hold recommendation. On a buyer-direct order, the buyer makes the release decision under its contract. On a Sinospect-supplied order, Sinospect records a supplier-side quality-control disposition; buyer acceptance and any payment or shipment consequence follow the signed contract.
When should the FAT be booked?
As soon as the plant can give a realistic test date, and before the set is boxed or containerised for shipment. Ask early which load bank the plant will use and its capacity, so a set larger than the bank or a power-factor requirement is found before the visit. Send the order scope and the expected readiness window.
07 · Getting started
What to send — start with what you have
Send the purchase specification and the test plan, if there is one. Sinospect uses them to propose the witness scope and assess feasibility.
Datasheet or purchase specification
Rating in kVA and kW, prime or standby, voltage and frequency, engine, alternator and controller, and any performance class.
Agreed FAT programme, if one exists
The plant's test plan or your own; otherwise Sinospect proposes the load steps and checks from the specification.
Purchase order and plant location
What was ordered, how many sets, and where the test bay is, so the visit can be arranged.
Load bank and power factor
Whether the plant's load bank is resistive or resistive-reactive, and its capacity against the set's rating.
Expected test-readiness window
When the plant expects the set ready, so witnessing is booked before it is boxed or containerised.
Send your test plan for a generator FAT quotation
Send the generating-set datasheet, the plant and the expected test window. Sinospect acknowledges the request within one business day. When the file is sufficient, the initial written assessment follows within two business days with the proposed scope, a quotation and the earliest feasible attendance, or explains plainly if a lighter control fits the order better.