Four ways to start a fire pump

How to start a fire pump

The relationship between the fire control room and the fire hydrant action button is related to the start-up form of the fire hydrant pump. There are generally two ways to start a fire pump. The first way is that under the bus system joint control mode, the start of the fire hydrant action button can send its required start signal to the fire control room console through the linkage interface module located next to the fire hydrant, and then output the switch contact that starts the fire hydrant from here.

The second way to start is to directly output the switch contact of the fire hydrant action button to the fire hydrant pump start box. Both of these starting methods can be used in actual design. The former method saves wiring, but it is necessary to program the address coding of the fire hydrant linkage module under the bus system to achieve the purpose of monitoring a large number of fire hydrants. The latter starting method is simple and reliable, but it is also necessary to return the fire hydrant action signal to the fire control room. Designers can choose according to the actual scale of the project in the specific design. The former starting method can be used for large-scale projects and complex architectural forms, and the latter starting method can be used for small-scale projects. The self-starting of the fire pump is achieved by the glass balls of the pipe network nozzles in each protection zone bursting at high temperature, causing the water flow of the pipe network, thereby linking the alarm valve pressure switch to act, and achieving the purpose of self-starting the sprinkler pump. Through the water flow indicator linkage module or the alarm valve pressure switch lead to the control room, the fire control room can accurately reflect its action signal, and the control room should be able to directly control the start and stop of the sprinkler pump.

Fire pump start-up method

1. Star-delta start-up mode

The star-delta start-up mode has a simple structure, low price and high reliability. For this reason, it is widely used to start by reducing the power to reduce the starting current of the equipment. The current characteristics are very good, but the torque characteristics are poor, so objectively it is only suitable for no-load or light-load starting occasions.

2. Auto-coupling step-down start-up mode

The auto-coupling step-down start-up mode uses an autotransformer to reduce the starting voltage applied to the stator winding of the motor. After the motor starts, the motor is separated from the autotransformer so that it can move normally under full pressure. This step-down start is divided into manual control and automatic control. Different taps of the autotransformer can be selected according to the allowable starting current and the required starting torque to achieve reduced voltage starting, and it can be used regardless of whether the stator winding of the motor is connected in Y or △.

3. Soft start mode

Soft start is to achieve smooth starting of motors and mechanical loads by adopting technical means such as voltage reduction, compensation or frequency conversion, reduce the impact of starting current on the power grid, and protect the power grid and mechanical system. This form is costly but has better protection for equipment. The voltage is slowly increased from zero to the rated voltage, so that the starting current of the motor during the starting process becomes controllable instead of the uncontrollable overload impact current in the past. And the size of the starting current can be adjusted as needed.

4. Direct start mode

The direct start mode of the fire pump is generally considered for water pumps below 15KW, and the starting load is not more than 20% of the capacity. The restrictions are large and the actual use is relatively small.