GB 50054-2011 Code for Design of Low-Voltage Power Distribution

General Provisions

• 第 1.0.1 条Purpose of this code: to ensure that low voltage power distribution design safeguards personal and property s…
• 第 1.0.2 条Scope: This code applies to the design of low voltage power distribution for AC, power frequency 1000V and be…
• 第 1.0.3 条Design principle: Low voltage power distribution design shall be safe and reliable, technologically advanced,…
• 第 1.0.4 条Equipment selection requirements: The equipment and materials used shall comply with current national product…
• 第 1.0.5 条Relationship with other codes: Low voltage power distribution design shall, in addition to complying with thi…

Terminology

• 第 2.0.1 条Low voltage distribution system : The distribution system from the low voltage side of the distribution trans…
• 第 2.0.4 条Distribution board : A device used to distribute electrical power. Distribution boards in hotel guest rooms a…
• 第 2.0.7 条Sockets : Guest room socket circuits in hotels shall be provided with residual current protection (operating …
• 第 2.0.8 条Lighting distribution : Residual current protection shall not be provided on hotel emergency lighting circuit…
• 第 2.0.9 条Grounding : Hotel buildings should adopt a TN S system (three phase five wire system), with a grounding resis…
• 第 2.0.10 条Equipotential bonding : Local equipotential bonding shall be provided in wet areas such as hotel bathrooms an…

Selection of electrical equipment and conductors

• 第 3.1.2 条The conductor cross section of distribution lines shall be selected based on the expected maximum continuous …
• 第 3.1.3 条The selection of electrical equipment and conductors should be adapted to the environmental conditions of the…
• 第 3.1.4 条The setting current of the overload protection device (e.g., circuit breaker) for a distribution line shall b…
• 第 3.1.5 条The short circuit protection device of a distribution circuit shall be capable of breaking the circuit before…
• 第 3.2.1 条The electrical devices inside distribution boxes (cabinets) shall meet the requirements for rated voltage (no…
• 第 3.2.2 条For electrical equipment used for motors (such as hotel air conditioning, elevators, water pumps), the rated …
• 第 3.2.3 条In lighting distribution circuits, the rated current of each single phase circuit should not exceed 16A , and…
• 第 3.2.4 条Socket circuits (e.g., guest rooms, public areas) shall be provided with a residual current device (RCD) with…
• 第 3.2.5 条For receptacle circuits in damp areas of the hotel such as kitchens, laundries, and swimming pools , the RCD …
• 第 3.3.1 条The insulation type of conductors (cables, wires) shall meet the requirements of the installation environment…
• 第 3.3.2 条When selecting conductor cross sections, the neutral line (N line) cross section should be the same as the ph…
• 第 3.3.3 条The cross section of the protective earthing conductor (PE conductor) shall meet the thermal stability requir…
• 第 3.3.4 条Distribution circuits in densely occupied areas of the hotel such as guest rooms and corridors shall use low …
• 第 3.3.5 条When multiple cables are laid in parallel , the ampacity must be derated according to the correction factor (…

Layout of power distribution equipment

• 第 4.1.3 条Aisle and operating distance : The width of the operating aisle in front of switchgear (panels) shall be ≥1.5…
• 第 4.2.1 条Distribution board installation height : The bottom edge of lighting distribution boards shall be ≥1.5m above…
• 第 4.2.3 条Wet area protection : Distribution boards (cabinets) in wet areas of the hotel, such as bathrooms, swimming p…
• 第 4.2.4 条Installation near combustible materials : Distribution boxes (cabinets) shall not be installed directly on Cl…
• 第 4.3.2 条Cable trench and cable tray spacing : In the hotel's strong current shaft, when cable trays are laid in multi…
• 第 4.3.4 条Firestop sealing requirements : Openings for incoming and outgoing cables of distribution cabinets (boxes), a…
• 第 4.4.1 条Bare conductor protection : Bare conductors shall not be used for power distribution in hotel public areas (l…
• 第 4.4.4 条Electrical clearance : In hotel distribution cabinets, the clear distance between bare conductors of differen…
• 第 4.5.1 条Emergency power transfer : The dual source transfer box for hotel fire loads (emergency lighting, fire pumps,…
• 第 4.5.3 条Standby power supply spacing : When the distribution cabinets in the hotel's diesel generator room are adjace…

Protection of distribution lines

• 第 6.1.2 条Distribution circuits shall be provided with short circuit protective devices capable of breaking the prospec…
• 第 6.1.4 条The operating characteristics of the overload protection device shall satisfy: \( I_B \leq I_n \leq I_z \) an…
• 第 6.2.3 条When the conductor cross section of a distribution circuit is reduced for overload protection (e.g., the bran…
• 第 6.2.4 条Overload protection devices should preferably be of the inverse time characteristic type (such as thermal mag…
• 第 6.3.3 条For socket circuits in densely occupied areas such as hotel guest rooms and meeting rooms, a residual current…
• 第 6.3.4 条The operating current of the residual current protective device shall ensure no nuisance tripping under norma…
• 第 6.4.1 条The short circuit protection device for distribution circuits shall be capable of breaking the circuit before…
• 第 6.4.2 条For hotel distribution trunk lines longer than 50 m (e.g., cables from the substation to the top floor equipm…

Laying of power distribution lines

• 第 7.1.2 条Distribution lines shall not be routed through areas with fire or explosion hazards; where routing is unavoid…
• 第 7.2.1 条When cables are installed indoors, mechanical damage and corrosion shall be avoided. In hotel public areas (s…
• 第 7.2.7 条When cables are laid in cable trenches or cable tunnels, the clear height should not be less than 1.9 m; the …
• 第 7.2.11 条When cables are laid in a cable tray, the total cross sectional area of the cables in the tray shall not exce…
• 第 7.3.4 条When wires are installed in conduits, the total cross sectional area of the wires inside the conduit (includi…
• 第 7.4.1 条When distribution lines pass through floor slabs or walls, protective conduits shall be provided, and the con…
• 第 7.4.3 条When routing wiring in wet areas of a hotel (such as bathrooms and kitchens), waterproof cables or waterproof…
• 第 7.5.2 条The distribution circuits for fire protection equipment in the hotel (such as emergency lighting and fire pum…
• 第 7.6.1 条When cables are laid within hotel ceilings, they shall be protected by metal conduits or flame retardant trun…

Laying of distribution lines

• 第 7.3.2 条When insulated conductors are installed exposed indoors, the horizontal run shall be not less than 2.5 m abov…

Engineering reference only — verify against project conditions and the latest codes.