1. Temporary power supply should not be connected to running production devices, tank farms and places with fire and explosion hazards. If it is really necessary to operate, first check whether there is combustible gas around;

2. All kinds of mobile power supply and external self-provided power supply should not be connected to the power grid, and power and lighting lines should be set in shunt;

3. A protective switch should be set for temporary electricity use, and the reliability of electrical devices and protective facilities should be checked before use. All temporary power consumption should be protected by grounding.

Line requirements

1. Temporary power lines with service life exceeding 1 month shall be installed overhead;

(1) Overhead lines shall be set on poles or supports;

(2) Overhead lines should not be erected on trees, scaffolding and temporary facilities;

(3) It is not suitable for joint connection on overhead lines. If a joint is needed, structural support should be carried out to ensure that the joint is not subject to tension and tension;

(4) The maximum sag of temporary overhead lines and motor vehicle lanes shall not be less than 6m.

(5) Overhead lines shall not be used in the access and operation areas of large equipment such as hoisting machinery.

2. Temporary power lines with service life less than 1 month can be installed by overhead or ground wiring:

(1) When the ground wiring is located in a busy traffic area or when heavy equipment passes by, it should be protected by concrete prefabricated parts, and safety warnings should be set;

(2) The protective sleeve shall not be less than 1.5 times of the external cable.

3. Requirements for temporary power grounding wire:

(1) The motor shall be equipped with insulated multi-strand copper wire with a diameter of not less than 2.5mm2;

(2) Hand-held electric tools should be equipped with insulated multi-strand copper wires with a size of not less than 1.5mm2;

(3) The cross-sectional area of cable is ≤ 16mm2, and the cross-sectional area of grounding conductor is not less than 5mm2；;

(4) The cross-sectional area of the grounding conductor with the cross-sectional area of 16~35mm2 shall not be less than 16mm2.

Electrical equipment requirements

1. Electrical equipment such as mobile tools and hand-held tools should have their own power switches, and the system of "one machine and one brake" must be implemented. It is forbidden to use the same switch for two or more electrical equipment (including sockets);

2. When using electrical equipment or electric tools in underwater or wet environment, insulation test shall be conducted: the basic insulation between the live part and the shell shall not be less than 2m Ω, and the reinforced insulation shall not be less than 7m Ω;

3. Hand-held power tools shall meet the following requirements:

(1) The electric shock protection of Class I hand-held electric tools includes basic insulation (insulation between live parts and shell) and protective grounding of metal shell;

(2) The second kind of electric shock protection for hand-held electric tools includes basic insulation, double insulation or reinforced insulation;

(3) The power supply voltage of Class III hand-held electric tools is safe voltage, and there is no safe voltage inside;

(4) In general workplaces, class II hand-held power tools should be used as much as possible. When using Class I tools, a leakage protector with rated leakage current not greater than 30mA and action time not greater than 0. 1s shall be installed;

(5) In narrow places (boilers, metal pipes, etc.). ), try to use class III tools. When using Class II tools, a leakage protector with rated leakage action current not greater than 15mA and action time not greater than 0. 1s shall be installed;

4. Temporary lighting shall meet the following requirements:

(1) lamps and lanterns must be controlled by switches, and the phase line shall not be directly introduced into lamps and lanterns;

(2) Use non-conductive materials to hang wires;

(3) The power supply for portable lamps shall not exceed 36V, the power supply for lighting in damp and charged places shall not exceed 24V, and the voltage of lighting power supply in floors, boilers or metal containers with good conductivity shall not exceed 12V.

Power transmission sequence and power failure operation sequence

1. Power transmission operation sequence: main distribution box → distribution box → switch box.

2. Operation sequence of power failure: switch box → distribution box → general distribution box.