在前一篇,我們介紹了低壓制櫃的FAT和SAT測試中Function Test 功能測試(TP5),以及ATS的Test (TP9)。見鏈接:
【低壓制櫃設計】低壓制櫃的測試(T&C of LV Switchboard 2 of 2)- 出廠驗收測試(FAT)和現場驗收測試(SAT)(Part 6)
(1) Arrangement of Test PanelCheck that the arrangement of the L.V Switchboard under test is correct and record all necessary information on the approved test form.(2) Test ConnectionsTest connections are fitted to each loaded circuits and short circuited at their remote end from the switchboard with the dimension of test conductors.Test current for the test is provided via 3 current transformers (1 per phase). These current transformers are connected to three individually variable voltage supplies, one per phase, for the provision of adjustment of the injected current independently. The typical connection method is shown in the figure of this section.(3) Current MeasurementAll outgoing circuits are equipped with one CT for each phase. Each of these CT's is then connected to an ammeter for current measurement. This arrangement facilitates regular monitoring of the intake current and distribution of the current to each test circuit.(4) Temperature MeasurementTemperatures are measured using thermocouples and temperature loggers.Thermocouples are adhered to the busbar surface by flame retardant tape at points of particular interest, where high temperatures are likely to be experienced. Details of the positions of thermo-couples are marked on the L.V Switchboard layout drawing.Ambient temperature is measured from the average of two thermo-couples adhered to both sides of the switchboard at least 1 metre apart from each other and approximately 1.2 metres above the ground.The locations of the thermocouples are shown on the temperature-rise test drawing. (Test points的數量及位置在測試需要經過業主/工程師審批,一般沿著主bar會儘量在不同節點設置Test points)
(5) Duration of TestCurrent is applied until temperature rise approaches the steady state, i.e. rising at not more than 1°C per hour, as stipulated by clause 10.10.2.3.1 of BS EN 61439-1:2011. During this period, slight mains voltage variations and increasing impedance of the test piece necessitate an occasional adjustment to the applied voltage. Temperatures are measured at hourly intervals throughout the test.(Temperature loggers會自動記錄並保存溫度數據)(6) Test ResultThe temperatures measured in each hour are recorded on the client-approved test form. The temperature rise shall not exceed the values as stipulated in Table 6 of BS EN 61439-1:2011.