Key points for fire pump power distribution design?
According to GB 50016-2014 (2018 Edition) Code for Fire Protection Design of Buildings and GB 50261-2017 Code for Construction and Acceptance of Sprinkler Systems, the power distribution design for fire pumps shall strictly follow the following key points:
1. Load classification: The electrical load of fire pumps shall be Class I or Class II load, determined specifically by the building category. Class I loads shall be supplied by two independent power sources with automatic transfer at the end; Class II loads should preferably be supplied by dual circuits.
2. Power source transfer: The fire pump control cabinet shall be provided with a dual-power automatic transfer device in the pump room, and the transfer time shall not exceed 15 seconds. The control cabinet shall be clearly labeled and equipped with manual/automatic transfer functions.
3. Distribution circuits: The power supply circuits for fire pumps shall use fire-resistant cables or mineral-insulated cables. When installed exposed, they shall be protected by metal conduits or enclosed metal raceways, and fire protection measures shall be taken (such as applying fireproof coating).
4. Protection requirements: Fire pumps shall not be provided with overload protection, only short-circuit protection. In the event of overload, an alarm signal shall be issued without cutting off the power supply, ensuring continuous operation for firefighting.
5. Control mode: The fire pump control cabinet shall have local manual, remote automatic (e.g., signal from the fire linkage controller) and manual direct start functions from the fire control room. The control cabinet shall be marked with the "Fire Pump" identification and provided with an emergency start button.
6. Voltage and grounding: The power distribution system shall adopt the TN-S system, with working grounding and protective grounding strictly separated. The rated voltage of fire pump motors is typically 380V; special locations (such as super high-rise buildings) may use high-voltage (e.g., 10kV) fire pumps.
7. Acceptance inspection: In accordance with GB 50261, it is required to test the dual-power transfer time, the pump start time (from receiving the signal to normal operation shall not exceed 2 minutes), and the linkage control function (e.g., direct start of the pump by the hydrant button).
8. Standby power source: If a diesel generator is used as the standby power source, its capacity shall meet the load of the fire pumps and auxiliary equipment (such as jockey pumps) operating simultaneously, and the generator self-start time shall not exceed 30 seconds.
It is recommended that the design refer to Chapter 11 power distribution provisions of the Technical Code for Fire Water Supply and Hydrant Systems (GB 50974-2014), and coordinate with the electrical discipline to ensure reliable power supply to fire pumps under all operating conditions.