FGI FD500 low voltage frequency inverter in the main and auxiliary pump water supply application

1.Overview

Urban water supply systems are an integral part of urban utilities. Urban water supply system planning is an integral part of urban master planning. The urban water supply system usually consists of water sources, aqueducts, water plants and distribution networks. After water is taken from the water source, it is sent to the water plant for water quality treatment through the water pipeline, and the treated water is pressurized and sent to the users through the distribution network.

2.Implementation plans

Working principle: 1 main pump and 1 auxiliary pump, the main pump runs for a long time, when the water supply is insufficient, the auxiliary pump is put into the frequency, when the pressure is too high, the auxiliary pump is disconnected. The main pump is controlled by frequency conversion and the auxiliary pump is put into operation only at working frequency.

Network pressure < set pressure, main pump speeds up, if 50HZ pressure is insufficient, Y1 is output after 15 seconds of setting, auxiliary pump is put into service.

Network pressure = set pressure, the current state is maintained and the water supply quantity remains unchanged.

If the network pressure > set pressure, the main pump speed decreases, and if the water supply is excessive, the main pump frequency decreases to the set value, then Y1 stops outputting and the auxiliary pump is disconnected.

Hardware requirements: 1 pressure sensor, 1 frequency inverter, 1 intermediate relay, 1 AC contactor, 1 thermal relay.

Process realization: the pressure sensor is installed on the water supply pipe network, the pressure value is converted into 0 ~ 10V signal (or 4 ~ 20 mA), transmitted to the frequency inverter, the PID operation to adjust the speed of the pump motor, when the main pump 50HZ water supply is insufficient, the FD500 low voltage frequency inverter is set to start the auxiliary pump by setting the Y1 output for 15 seconds, when the water supply is too much, then the main pump speed decreases, and if the speed is low enough to set the lower limit value of the Y1 disconnect, disconnecting the auxiliary pump time.

3.Application advantage

Energy saving is remarkable: saving electricity about 40%-50%, saving coal about 5%-10%.

Full combustion, less residue, effectively reduce the pollution of the environment.

Soft starting, small impact, avoid water hammer, save maintenance costs.

Stepless speed regulation, simple operation, convenient speed regulation.

Reduce the high-frequency noise of the motor, improve the environment.

Proper protection function, a variety of alarms real-time monitoring, safer, more secure.