Concrete plant commissioning of power cabinet and operation platform

Commissioning of a concrete batching plant entails checking of every of the numerous parts of the plant. Here we deal with power cabinet and operation platform of a concrete mixing plant.

1. Check whether the three-phase power balance is stable and whether there is phase loss (check whether there is short circuit, ground connection and wrong connection in the circuit by voltmeter).

2. Check the rationality of wiring

2.1 Check whether the model and layout of components are consistent with the electrical drawings

2.2 Use a multi-meter to check whether there is short circuit or wrong connection in the circuit. If there is short circuit or doubt, the problem shall be fully identified before the next work.

2.3 Check the insulation of the motor with a 500V megger to see if there is any phenomenon to the ground

2.4 Check that the resistance between 100 lines is not more than 1 ohm.

2.5 Check whether the ground wire is in good contact and firm.

2.6 Make sure that the sensor signal line is as far away from the high current line as possible

2.7 check electrical parameters in power cabinet.

Small plants like an hzs35 concrete batching plant should also be dealt with in the same way.

3. Check the correctness of the circuit

3.1 disconnect all circuit breakers and fuses.

3.2 close the main circuit breaker QF, connect fuse fu1 and fu2, then close the control power switch so, and check whether the transformer output is normal.

3.3 check whether the output of 24V switching power supply is normal.

3.4 connect fuses one by one, PLC is powered on, panel power indicator works, weighing instrument is powered on.

3.5 carefully observe whether all components have heat and burning smell.

3.6 check whether the voltage is correct one by one with Multimeter according to the schematic diagram.

4. Check the correctness of PLC input circuit

4.1 place the PILC in the "stop" position

4.2 check whether the indicator lights of all knob switches, button switches and on-site emergency stop switches on the panel are on / off one by one

4.3 check limit switch, level gauge and electric contact pressure gauge of compressed air pipe one by one

4.4 check the maintenance protection switch, press the motor start button when opening, check whether there is signal input at pic input point, especially whether the function position of each knob corresponds to its input signal)

5. Check the correctness of external circuit of PLC output part

5.1 carefully check the resistance to ground of each output point with a multi-meter for short circuit

5.2 carefully check whether each control circuit is consistent with the drawing by comparing the schematic diagram (pay special attention to check whether the corresponding voltage level of the control circuit PLC module with different voltage levels is consistent before power on)

6. Check whether the shielding cable of each scale corresponds to the instrument terminal.

7. Check whether the emergency stop button is effective.

In particular, operation platforms of large concrete mixing plants like an hzs120 concrete batching plant should be checked in great detail, for their automatic functions are likely to be used more frequently.