nominal low voltage meaning in English

额定低压

Single or three phase at nominal low voltage are required to be inspected , tested and certified at least once every five years . examples of such installations are power supply to lifts , water pumps , public lightings and other communal services in the common area of domestic premises and fixed installations in offices etc . having total loading exceeding 100 amperes , single or three phase
（单相或三相）时，该装置须每5年最少作一次检查、测试及领取证明书。这类装置包括住宅楼宇内升降机、水泵、公共照明及其他公用设施的供电装置，办公室内的固定装置等，其总负载量超逾100安培（单相或三相）。