Can the fire pump controller be used with ordinary pumps?

2020-04-29

In some cases, we need to use a control cabinet for fire pumps, the main purpose is to save costs and equipment footprint. So which pump control cabinet can make life and fire pump use one control cabinet? Some of the intelligent water pump control cabinet produced by our company has the following functions.

The intelligent water pump control cabinet shall have the following functions:
1. Frequency control
Frequency conversion control is based on the pressure of the pipe network, the pressure signal is fed back to the frequency converter from the remote pressure gauge, and then the frequency conversion output changes the motor speed to achieve the purpose of constant voltage. This method is not only constant pressure but also energy-saving (the working current is small, especially when the flow rate is small, the pump can sleep and stop), and the performance is superior. 

 2. Manual operation:
The switch 3SAC of the fire pump manufacturer is placed in the "manual" state, at this time the pump can only be operated by manual power frequency. When the power is turned on, the power indicator of the control cabinet lights, press the 1 # pump "start" button, the 1 # pump motor starts to run, and the "1 # pump power frequency" indicator lights. Press the 1 # pump "stop" button, the 1 # water pump motor stops working, and the "1 # pump power frequency" indicator is off. When the transfer switch of the control cabinet panel is placed in the "manual" position, the motor start and stop of the water supply equipment can only be manually controlled by the "start / stop" button on the control cabinet panel. At the same time, the indicator shows that only the "power frequency indicator" is valid. Other situations are similar. If it does not start with frequency conversion, the manual operation is to start the voltage reduction through the soft starter.

3. Automatic operation (controlled by PLC):
The transfer switch 3SAC is placed in the "automatic" state, and the pump's automatic allows the knob switch to be turned to the "on" position. Only when the automatic permission knob switch of the 1 # water pump is in the "on" state can the 1 # water pump participate in the work (frequency conversion or power frequency). Other working conditions are similar. When there is a fire alarm (controlled by remote control of fire center or button of fire hydrant box), a start signal is sent to the control cabinet. At this time, PLC receives the fire signal, after a certain delay, it stops water supply to the living area, and the system works under fire pressure. The water pump is driven by the frequency converter to provide constant pressure water supply to the fire fighting equipment.

4. Other functions:
A. Automatic increase / decrease pump function
B. Failover function
C. Knob switching function
D. Timed automatic rotation function
E. Water shortage protection function
F. Fault indication function


 
A. Automatic increase / decrease pump function
When the power is turned on, the power indicator of the control cabinet lights, and when the pool is not short of water, after a delay of a few seconds, the 1 # pump motor automatically starts running with frequency conversion. When the water supply of the 1 # pump cannot meet the external water consumption, the system automatically adds the pump, automatically converts the 1 # pump to power frequency operation, and delays the automatic frequency conversion to start the 2 # pump. When there is more than one running (ie, there are multiple pumps running), and the water supply of the pump is greater than the user's water consumption, the system automatically reduces the pump, and the principle of reducing the pump is "start first and stop first", that is: work first The pump should be stopped first. After this continuous dynamic adjustment, until the system water supply pressure reaches a certain balance. 

B. Failover function
When the 1 # pump frequency conversion operation signal is output, the feedback signal is detected for a delay of 1 second. If the feedback signal is still not engaged, the output of the 1 # pump frequency conversion operation signal is cut off and automatically switched to the next stopped pump. Send an alarm signal. After the fault is eliminated, press the "Fault Reset" button (a pulse signal) on the panel of the control cabinet to remove the fault signal memorized by the PLC, and the fault signal indication goes out. The frequency conversion work of other pumps is similar. 

C. Knob switching function
When the 1 # water pump frequency conversion operation signal is output, turn the 1 # water pump automatic permission knob switch to the "off" position. At this time, the 1 # water pump frequency conversion operation signal is turned off, the operation signal is extinguished, and automatically switch to the next stopped water pump. The frequency conversion work of other pumps is similar. 

D. Timed automatic rotation function
When the frequency conversion operation signal of the 1 # water pump is lit, and the other stabilized pressure pump is in a stopped state, after a certain time (set within 24 hours in the PLC), it will automatically switch to the next water pump 2 # to make the frequency conversion operation At this time, the two regulator pumps must automatically allow the knob switch to be in the "on" state. The working conditions of 2 # water pump frequency conversion are similar. 

E. Water shortage protection function
The adequacy of the pool water source will directly affect the start and stop of the system pump. When the pool is short of water, disconnected, the system will automatically stop the operation of the pump (power frequency and frequency conversion). 

F. Fault indication function
When each water pump fails (such as overload, etc.), the system automatically stops the output of the corresponding water pump in the PLC, cuts off the power of the motor, terminates the motor operation, and makes corresponding indications of the fault.