Electricity safety regulations, the ground voltage of 250V or less for low-voltage equipment.
Low-voltage equipment generally refers to low-voltage electrical equipment, low-voltage electrical equipment is a good distribution of finished products, such as control cabinets, compensation cabinets, inlet cabinets, outlet cabinets, frequency control cabinets, soft start cabinets. Where the voltage to ground 250V and below is low voltage, the electrical device used in the low voltage class is low voltage electrical device. AC system of 220V three-phase four-wire system of 380V/220V neutral grounding system are low voltage. Line voltage 380V although more than 250V, but the phase voltage (line to ground) is 220V, so it is low voltage.
In order to ensure the normal power supply to the place of electricity, the distribution screen on the instrument and electrical appliances should be frequently checked and maintained, and make a good record, in order to analyze the operation and use of electricity at any time, and timely detection and elimination of hidden problems. Distribution screen and the name of the electrical components on the screen, signs, numbers, etc. are clear and correct, all the operating handle on the disk, buttons and keys, etc. location and the actual situation on the spot whether it is consistent with the fixation of whether it is secure, whether the operation is flexible.
Low-voltage electrical equipment work precautions
1, low-voltage electrical work with electricity should wear gloves, goggles, and keep the ground insulation.
2, voltage distribution network in the opening equipment should be easy to operate, and have obvious opening instructions.
3, low-voltage electrical work before the application of low-voltage tester or stylus to check the maintenance equipment, metal casing and neighboring equipment whether there is electricity.
4, low-voltage electrical work, measures should be taken to prevent accidental entry into adjacent intervals, accidentally touching adjacent energized parts.
5, low-voltage electrical work, disassembled leads, disconnected wires should be insulated package and other masking measures.
6, low-voltage electrical work with electricity, insulation and isolation measures should be taken to prevent phase-to-phase short circuit and single-phase grounding.
7, low-voltage electrical energized work, the operation of the electrical circuit within the scope of the residual current action protection device should be put into operation.
8, low-voltage electrical energized work with tools should be insulated handle, its exposed conductive parts should be insulated package measures; prohibit the use of files, metal rulers and brushes with metal, duster and other tools.