{"id":5180,"date":"2026-09-03T14:00:04","date_gmt":"2026-09-03T06:00:04","guid":{"rendered":"https:\/\/www.solidess.com\/?p=5180"},"modified":"2026-09-03T14:00:04","modified_gmt":"2026-09-03T06:00:04","slug":"ci-bess-testing-fat-sat-performance-acceptance","status":"publish","type":"post","link":"https:\/\/www.solidess.com\/xh\/ci-bess-testing-fat-sat-performance-acceptance\/","title":{"rendered":"C&I BESS FAT vs SAT: Yintoni kanye ekhutshwa yi-PASS"},"content":{"rendered":"
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For a 400 V MegSolid C&I BESS<\/a><\/strong> project, the owner\u2019s electrical engineer and EPC commissioning lead need one answer before commercial operation: which result belongs to FAT, which belongs to SAT and which still requires a separate performance run. A FAT PASS<\/a><\/strong> clears the identified model, bill of materials and software build for shipment; a SAT PASS clears the installed meters, CTs, protection, communications and control sequence at site; a performance PASS<\/a><\/strong> accepts only the contracted kW, kVA or usable AC kWh measured at the agreed boundary. If one PASS is allowed to stand in for all three, a reversed PCC CT, wrong meter scaling, firmware mismatch or unverified energy shortfall can leave the test file and enter commercial operation.<\/p>\t\t\t\t<\/div>\n\t\t\t\t

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The Three Acceptance Gates<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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FAT, SAT and performance acceptance cover different physical boundaries. Read an acceptance file by asking where the equipment was, what was connected and which decision the signature supported.<\/p>\t\t\t\t<\/div>\n\t\t\t\t

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Acceptance gate<\/th>Where it happens<\/th>Question answered<\/th>What the PASS supports<\/th>Okusele kuvuliwe<\/th><\/tr><\/thead>
Factory acceptance test<\/td>Manufacturer or integration facility<\/td>Was the ordered configuration assembled, identified and functionally checked before shipment?<\/td>Release of the tested configuration for shipment, subject to the contract<\/td>Site wiring, PCC metering, local protection and delivered AC performance<\/td><\/tr>
Site acceptance test<\/td>Installed project site<\/td>Do the actual meters, CTs, breakers, protection, communications and control interfaces work together?<\/td>Functional release of the installed interfaces<\/td>Contracted kW, kVA or usable AC kWh unless the procedure includes a separate measured run<\/td><\/tr>
Performance acceptance<\/td>Agreed AC delivery point<\/td>Does the installed system deliver the contracted duty under the stated conditions?<\/td>Acceptance of the measured power, energy or power-quality result<\/td>Functions or interfaces that were not exercised during that run<\/td><\/tr><\/tbody><\/table><\/div>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
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The contract decides whether a PASS also triggers shipment, payment, warranty commencement or final acceptance. The test report still has to state its technical boundary. PCC CT direction belongs in SAT, and an emergency trip belongs in functional SAT, even when the factory or capacity report says PASS.<\/p>\t\t\t\t<\/div>\n\t\t\t\t

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From Factory Floor to Commercial Operation<\/h3>\t\t\t\t<\/div>\n\t\t\t\t
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Each handoff should leave one record for the next team:<\/p>\t\t\t\t<\/div>\n\t\t\t\t

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FAT \u2192 shipment \u2192 installation \u2192 energization \u2192 SAT \u2192 performance acceptance \u2192 handover<\/strong><\/p>\t\t\t\t<\/div>\n\t\t\t\t

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The factory record travels with the identified model, serial numbers and software build. The site team adds the actual switchboard, transformer, CTs, meter, communications network and protection settings. Performance acceptance then uses those stable interfaces to measure the contracted result at the named AC boundary.<\/p>\t\t\t\t<\/div>\n\t\t\t\t

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An EMS update after FAT gets its own revision entry and a repeat run of every function it changes. A replacement PCC meter adds its serial number, ratio, polarity, sign convention and time source to the SAT record. Factory results for unaffected functions remain tied to the configuration that was tested.<\/p>\t\t\t\t<\/div>\n\t\t\t\t

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When the cabinet, site wiring and measured energy are merged into one PASS, the next reviewer cannot tell which part was released or which change occurred after the witness left.<\/p>\t\t\t\t<\/div>\n\t\t\t\t

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Factory Release: What FAT Proves and What Remains Open<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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A FAT pass proves that the identified equipment matched the agreed factory scope when it was tested. A useful record starts with identity: model, serial numbers, battery configuration and bill of materials. It then names the approved hardware and software revisions used for the run, records how the available factory functions responded and links every open deviation to a retest or disposition.<\/p>\t\t\t\t<\/div>\n\t\t\t\t

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A cell, module, rack, cabinet, transformer and protection panel do not share one test method. Grenergy described the Oasis de Atacama Phase I FAT<\/a> across cell, module, frame and system levels. For a West African C&I project, Spenomatic reported witnessing a 10 MWh BESS FAT<\/a> at the equipment factory. Each announcement names the tested level and witness scope. \u201cThe BESS passed\u201d omits both.<\/p>\t\t\t\t<\/div>\n\t\t\t\t

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For an integrated C&I cabinet, the factory can exercise internal battery-to-PCS limits, EMS commands, thermal-management response, alarms and communications available within the supplied boundary. The factory cannot reproduce the final CT orientation, site transformer behavior, switchboard fault duty or local network path merely by simulating their signals.<\/p>\t\t\t\t<\/div>\n\t\t\t\t

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Model\/BOM reconciliation, firmware control, witness evidence and retest rules belong in the controlled factory procedure. FAT clears an identified factory configuration. The installed plant waits for SAT.<\/p>\t\t\t\t<\/div>\n\t\t\t\t

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Site Release: What SAT Proves at the PCC<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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SAT begins where factory simulation ends. The installed switchboard, transformer, CTs, meter, breaker wiring, protection relays and site network now determine what the controller sees and how the BESS responds.<\/p>\t\t\t\t<\/div>\n\t\t\t\t

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At a 400 V factory switchboard, a commissioning engineer commands discharge and sees PCC import rise. The first check is the installed measurement chain. A reversed CT or inverted sign convention makes a correct cabinet response look wrong to the EMS, which then increases the wrong command. The fault belongs to SAT.<\/p>\t\t\t\t<\/div>\n\t\t\t\t

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The site record needs to establish four interface groups:<\/p>\t\t\t\t<\/div>\n\t\t\t\t

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