4.1.2 Safety measures such as short-circuit protection, overload protection, ground fault protection and over-voltage and under-voltage protection of power supply and distribution systems and electrical equipment should be reasonably selected according to the nature and capacity of the load.

4.1.3 The voltage drop of the power supply line should not be greater than 5% of the supply voltage.

4.1.4 The distribution box should be set up according to the fire compartment.

4.1.5 In the building with electrical fire monitoring system, the pyrolysis particle type electrical fire monitoring detector should be installed at the top of the power distribution cabinet in the floor distribution room; the cable tunnel and mezzanine with ventilation system should be at the return air outlet. Set the duct smoke detector; connect the alarm signal to the electrical fire monitoring system.

4.2 Distribution Substation

4.2.1 When the substation is located in the basement, measures should be taken to prevent flooding, fire water or stagnant water from flooding the substation from other channels.

4.2.2 High-rise buildings with a building height of more than 100m can be distributed in the refuge, equipment and roof layers.

4.2.3 The inlet and outlet cables laid in the substation shall be considered for the overall flame retardant requirements. When there are total and sub-substations in the building, the 10 (20, 35) kV cable from the total substation to the substation shall be fire-resistant cable; the distribution line from the high-voltage generator set shall be fire-resistant cable.

4.2.4 When the low-voltage distribution cabinet of the substation is on the upper line, the fire-fighting cable shall be laid with a special bridge. When the line is out, the fire-fighting cable and the non-fire-fighting cable should be arranged on different sides of the cable trench or the fire-fighting cable should adopt the NH1 grade fire-resistant cable in Appendix A.

4.2.5 The cable trench cover should be made of non-combustible material.

4.2.6 Pipes unrelated to substations should not pass through substations.

4.2.7 The holes in the walls and floors of the substation shall be fireproofed.

4.2.8 The distribution equipment of fire-fighting equipment and the distribution equipment of non-fire-fighting equipment should be installed separately; if it is necessary to install in parallel, the boundary shall be provided with fireproof partition.

4.3 High-voltage power distribution equipment and transformers

4.3.1 Substation equipment selection should meet the following requirements:

1 Dry-type transformers, gas-insulated transformers or non-combustible liquid-insulated transformers should be selected; dry-type transformers can be used for outdoor independent construction and substation, and oil-immersed transformers can also be used;

2 Circuit breakers with flammable oil should not be used;

3 Capacitors made of metallized capacitors or other non-combustible materials should be used;

4 naked busbar wiring should not be used;

5 The metal enclosure or base of the power distribution unit should be reliably grounded.

4.3.2 Non-combustible materials shall be used for the distribution of interior decoration materials.

4.3.3 In addition to the independent substation and outdoor box-type substation, electrical fire monitoring detectors shall be installed in transformers and power distribution cabinets; smoke detectors shall be installed in each room of substations installed in buildings. .

4.4 Daily common load distribution

4.4.1 The daily common electric load design shall comply with the requirements of the current national standard “Low-Voltage Power Distribution Design Specification” GB50054.

4.4.2 When the distribution line is prone to electric leakage and cause electrical fire, the residual current type electrical fire monitoring detector shall be added to the distribution line of the non-fire protection load.

4.4.3 Power distribution equipment should not be installed directly on the surface of combustible materials.

4.4.4 When using non-flame-retardant and fire-resistant cables for distribution lines, one of the following measures should be taken for distribution boxes and distribution cabinets:

1 Set the temperature-measuring electrical fire monitoring detector at the terminal block or set the pyrolysis particle type electrical fire monitoring detector inside the box;

2 In the inlet and outlet, do fireproof sealing, and the cable brush should be no less than 1m long.

5 Fire power

5.1 General provisions

5.1.1 The fire-fighting electricity plan should be reasonably determined according to the type and scale of the building, and the design principles of separate design and separate protection of fire load and daily power load should be followed.

5.1.2 The design of fire-fighting electricity shall ensure that the fire-fighting equipment can be used normally during the fire, and there are measures to prevent the non-fire-fighting power supply from being unaffected.

5.1.3 Fire emergency alarm system and evacuation system shall be equipped with fire emergency power supply; fire-fighting emergency power supply shall be set up in the place where fire-fighting system can only be implemented by the fire-fighting system provided by the building.

5.1.4 High-power fire-fighting equipment should be powered by a separate distribution loop.

5.1.5 When there are multiple electric fire-fighting equipments in the same power supply circuit, it is advisable to calculate the load capacity according to the time-sharing.

5.1.6 When the insulation of the fire-fighting power supply line may be lowered due to moisture or other factors, the measurement of the insulated electrical fire monitoring detector or the measurement residual current type electrical fire monitoring detector with compensation function shall be provided, and the cutting device shall not be provided.

5.1.7 In the construction of the fire control room, if the fire control room cannot determine the power status, the fire power monitoring system should be set up.

5.2 Fire negative charge level and power supply requirements

5.2.1 The fire load rating should not be lower than the highest level of daily electrical load for the building.

5.2.2 The fire-fighting electrical load of civil buildings with a building height of more than 150m shall be powered by two low-voltage circuits of dual power supply. The red fire-fighting power distribution cabinet shall be separately provided, and a self-provided emergency generator set shall be provided.

5.2.3 For civil buildings with a building height of more than 100m but not exceeding 150m, an emergency generator set should be provided; when a civil building with a building height of more than 54m but not exceeding 150m is not provided with an emergency generator set, a special interface for emergency power generation vehicles should be provided; For civil buildings of 24m but not exceeding 54m, special interfaces for emergency generators should be provided.

5.2.4 The fire load rating shall meet the following requirements:

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