Electric control system common faults in HZS series concrete batching plants

 Electric control system common faults in HZS series concrete batching plants:

1. meter display is inaccurate.

When the material is weighed, the display value of the batching control instrument is consistent with the set value, but the actual value of the material is greater or less than the display value. The causes of the faults may be: the weighing system is affected by external forces; the sensor drift error causes the change of weighing zero or weighing distance; and the sensor is damaged.

At this point, we should eliminate the external force and re calibrate the zero position. The load of multiple sensors should be taken into account. If a sensor is damaged or the cable is loose or damaged, the sensor should be replaced and the cable checked.

2. accuracy of batching accuracy.

In the course of batching, the weighing value displayed by the batching control instrument is accurate, but the weighing value of the batching does not match the set value, and the batching accuracy exceeds the allowable range. There are many reasons for such faults, including: the setting of fast and slow batching is not appropriate; the large fluctuation of feed flow, resulting in large changes in excess impulse; the material dry and humidity changes; the allowable range set value is too large; the setting of delay time for excess inspection is too short; the automatic compensation of instrument parameters and the setting of excess inspection is unreasonable; The time parameter values of filtering and batching are not set reasonably.

The following measures should be taken for the above reasons: the initial excess impulse should be as close as possible to the actual value; the appropriate flow rate should be reduced; the dry and humidity of the material should be balanced; the allowable deviation should be set within the range of batching accuracy; the delay time of the excess inspection should be set more than 2.5 seconds; the instrument parameters should be automatically compensated and the excess inspection should be carried out. They should be set to "1", and the appropriate parameter values should be set in batching.

3. silos are not involved in batching.

It is shown that a silo does not participate in the batching process, the relevant batching indicator lights on the instrument and operation panel, but the motor or solenoid valve does not move. The causes of this failure may be: insufficient air pressure of the scale; damage to the relevant batching actuators (motors or solenoid valves); loose and virtual connection between AC contactors and motors; damage to intermediate relays and contactors in related circuits and abnormal connection.

At this time should check the air compressor and air circuit connectors, use a multimeter to check the motor, solenoid valve and related circuits, timely replacement of intermediate relays or AC contactors. If the relevant batching indicator is not on and the instrument is not moving when this fault occurs, it may be that the batching control instrument is damaged or the power supply is abnormal.

4. no unloading of bunker.

It is manifested that a silo does not unload under the automatic working conditions, and the operation panel on the silo unloading indicator lights and the scale unloading indicator lights are not on. The cause of this failure may be: the discharging door of the mixer is completely closed, but the shutting signal is not fed back to the controller; the limit switch is damaged or shifted; a silo does not start the batching. At this point should check the limit control feedback circuit, adjust or replace the limit switch, timely start the "batching tool" for feeding, semi-automatic way to complete the current batch production.

If this fault occurs, the operation panel on the bin unloading indicator lights, the reason may be insufficient air pressure or discharge cylinder leakage is serious, should promptly check the air circuit, replace wear parts; if the solenoid valve does not have 220 V AC power supply, it may be intermediate relay coil burning, solenoid valve power supply circuit connection is not good, should and If the solenoid valve has 220 V AC power supply, it may be the solenoid valve coil burning, valve core stuck, valve body seal damage, should be replaced in time solenoid valve.