Single and multi-storey residential buildings:
Residential buildings with building height not more than 27m (including residential buildings with commercial service outlets)
Single and multi-storey public buildings:
1. Single storey public buildings with building height greater than 24m.
2. Other public buildings with building height no more than 24m.
Fire resistance rating of single and multi-storey buildings:
The fire resistance rating of single and multi-storey important public buildings shall not be lower than grade II.
The fire protection power of the following single and multi-storey buildings shall be supplied according to the secondary load:
Note: refer to Appendix A of JGJ 16-2008 for classification of other non fire power loads.
Class I high-rise residential buildings:
Residential buildings with a building height of more than 54m (including residential buildings with commercial service outlets).
Class II high-rise residential buildings:
Residential buildings with a building height of more than 27m but not more than 54m (including residential buildings with commercial service outlets)
Class I high-rise public buildings:
Class II high-rise public buildings:
Other high-rise public buildings except class I high-rise public buildings (the building height is more than 24m).
(1) The fire protection requirements of non residential residential buildings such as dormitories and apartments shall be implemented in accordance with the provisions of public buildings;
(2) The fire protection requirements of the podium shall be in accordance with the provisions of high-rise civil buildings.
Fire resistance rating of high-rise buildings:
1. The fire resistance rating of class I high-rise buildings, underground or semi underground buildings (rooms) shall not be lower than class I;
2. The fire resistance rating of class II high-rise buildings shall not be lower than class II.
Load classification of fire power in high-rise buildings:
Level I load: fire control room, automatic fire alarm and linkage control device, fire emergency lighting and evacuation indicator, smoke control and smoke exhaust facilities, automatic fire extinguishing system, fire pump, fire elevator and its drainage pump, electric fire roller shutter, door and window and valve of class I high-rise building;
Class II load: the above-mentioned fire-fighting power in class II high-rise buildings.
Note: According to technical code for fire water supply and hydrant system (gb50974-2014)
Article 9.2.1: fire fighting and drainage measures shall be taken for the following buildings and places:
(1) Fire pump room;
(2) Basement with fire water supply system (such as underground garage);
(3) The shaft bottom of the fire elevator;
That is, the sewage pump in the above places belongs to "fire load" and shall be graded, supplied and distributed according to the requirements of "fire load".
Load classification of non fire power in high-rise buildings:
Class I load: power for walkway lighting, duty lighting, guard lighting and obstacle lighting of class I high-rise buildings, power for main business and computer system, power for security system, power for electronic information equipment room, power for passenger elevator, power for sewage pump and domestic water pump;
Class II load: power for lighting of main passageways and staircases of class II high-rise buildings, power for passenger elevators, power for sewage pumps and domestic water pumps.
For the power distribution system diagram of star delta step-down starting motor, the cables, contactors, thermal relays and other equipment in the power supply circuit shall be selected according to 1 / √ 3 (i.e. 0.58 IR) of the rated current of the motor.
Power distribution system diagram of dual-purpose dual-speed fan in peacetime / fire, analysis:
For the fire motor power distribution system diagram, the analysis is as follows:
1. The distribution protection outgoing switch of the fire motor shall be of single electromagnetic type, that is, the conventional thermal magnetic composite type shall not be selected, and the thermal release shall be canceled to realize no tripping when the motor is overloaded;
2. As for the dual power incoming switch ATSE and its superior switch of the fire motor, these switches belong to the "protection of the fire protection line". As for the line only, the fire load is constant and "the line cannot be overloaded", it does not matter whether these switches are set or canceled with "overload protection" (according to code for design of low voltage power distribution gb50054-2011: 6.3.5).
Generally, if the overload long delay setting current value IZD of these switches is ≥ 1.5 ~ 2 times of the rated current ie of the motor, they will not trip when the end motor is overloaded.
There is no doubt that the protection of the fire motor has been completed by the circuit breaker and thermal relay in the control box of the fire motor, and they can only implement the "protection of the motor"! At this time, as mentioned above, the circuit breaker shall be of single electromagnetic type, and the thermal relay shall only alarm without tripping when overload.
The commonly used fire-fighting motor (fan, water pump) shall trip in case of overload! When the standby fire-fighting motor is overloaded, it only gives an alarm without tripping and insists on working.
Its reliability shall not be lower than that of the main circuit power supply. Multiple working pumps and standby pumps cannot share one control power supply.
Motor control box (control button or control switch):
It should be located near the motor for easy operation and observation. Otherwise, the remote control box should be equipped with light off signal or instrument indicating the working state of the motor.
55kW and above motor: current measuring device shall be installed.
Design measures and technical measures for "local manual control on site and remote control release" of motor:
1. The on-site control box is provided with manual control start / stop button. The "isolation switch" is directly added to the primary main circuit to cut off the primary main power supply and release the remote control;
2. The field control box adds a "change-over switch" in the secondary control circuit. By setting the "local" or "0" neutral position, the power supply of the secondary control circuit is cut off, so that the coil of the AC contactor cannot be powered on, and the contact of the primary circuit is disconnected, thus cutting off the primary main power supply and releasing the remote automatic control.
Power distribution of electrical equipment in wet places such as drainage pumps or outdoor places:
1. Ground fault protection (CPS with RCD protection and 30mA action) shall be adopted for all kinds of drainage pumps, including the fire pump house and fire elevator foundation pit drainage pump for fire protection, which shall be established at the same time as the "standby pump only alarms but does not trip" of the fire drainage pump.
2. Socket, bathroom shower, roof fan, solar hot water pump, air conditioner outdoor unit; The distribution circuit of landscape lighting, facade lighting, festival lights, aviation obstacle lights, etc. shall be equipped with residual current action protection device (RCD) with an action current of 30mA.
For wiring system diagram of motor distribution box:
In addition to the primary main circuit diagram, the design drawing shall also draw the secondary control schematic diagram of the motor (fan, water pump), or "mark" the national standard atlas number, corresponding page number, necessary instructions, etc., and the page number shall be marked accurately.
AC motor shall be equipped with short-circuit protection and ground fault protection
Floor distribution box with trunk power distribution:
The power incoming line is led out from the branch of the main line. When the line length is l > 3M, protective appliances shall be set at the branch to protect the branch line;
Or the branch line shall have the same section as the main line to ensure that the branch line can be protected by the main switch of the main line in case of short circuit.
During load calculation, the parameters such as demand coefficient KX, active simultaneous coefficient K Σ P = 0.8 ~ 0.9, reactive simultaneous coefficient K Σ q = 0.93 ~ 0.97 and power factor cos ￠ shall be correctly selected.
1. The demand coefficient KX is larger;
2. The simultaneous coefficient of active and reactive power is unreasonable;
3. The power factor cos ￠ is smaller.
For lighting and power loads with different power factor cos Ø, when the distribution cabinet (box) is shared, the current of the incoming line of the power supply shall be calculated by the simultaneous coefficient method according to the apparent capacity (active power and reactive power are separately counted).
For power supply of fire control room, fire pump, fire elevator, smoke exhaust fan, etc., automatic switching device shall be set at the last level distribution box.
Power supply trunk lines and distribution boxes shall be set according to different load categories.
1. From the substation to the single building, the main incoming line of power supply: according to the requirements of itemized measurement, it shall be separated according to the classification of lighting, power, air conditioning, special power consumption, etc., and the power supply trunk line and distribution box shall be set respectively for management and billing.
2. Products with remote transmission function shall be selected for classified and itemized energy metering devices to facilitate the setting of independent energy management system and networking with building equipment management system (BA) to realize data sharing.
The main incoming line of power supply shall be provided with electrical appliances with isolation and protection functions.
The power supply and distribution system shall be simple and reliable. The distribution level of the same voltage level shall not be more than two levels for high voltage and three levels for low voltage.
The selection range of four pole switch is as follows:
In addition to the above provisions, three pole switches shall be used in principle if there are no special requirements.
The main differences between automatic transfer switch (ATSE) PC level and CB level are:
1. CB level ATSE can break short-circuit current, but PC level can not;
2. The conversion time of PC level ATSE is about 0.1s, and that of CB level ATSE is 1-3s.
The rated current of PC level ATSE shall not be less than 125% of the loop calculation current.
The incoming line side of automatic transfer switch (ATSE) should not be equipped with isolating switch or circuit breaker.
The inter stage selective interlocking technology is adopted to ensure the selectivity of the upper and lower switches in case of short-circuit fault, so as to effectively solve the problem of large-scale power failure caused by skip tripping.