Block Making Machine in Saudi Arabia

The electrical system of a cement brick machine is the "nerve center" of its operation, responsible for controlling power output, coordinating movements (such as material placement, pressing, and demolding), and providing safety protection. Failures can directly cause equipment downtime, impacting production efficiency. The following, based on the equipment's operating logic, identifies six common electrical faults and explains their symptoms, possible causes, and basic troubleshooting guidelines to help quickly locate the problem:

1. Power Circuit Failure: The Motor Does Not Start or Immediately Shuts Down After Starting

1. Failure Symptom
After pressing the start button, the main motor/hydraulic pump motor shows no response (no noise, no rotation);

The motor trips instantly upon starting (circuit breaker/ground fault protector trips);

After starting, the motor experiences abnormal speed (stuttering, low speed), accompanied by unusual noise or overheating.

Core Cause
Fault Type Specific Cause
Power supply abnormality: The workshop's main power supply voltage is too low (less than 360V, causing the motor to be unable to generate rated torque) or a phase is missing (one phase is missing from the three-phase power supply);
Loose equipment power cords or oxidized connectors (e.g., poor contact at the motor terminals).
Protection device triggered: The motor overload protector (thermal relay) is activated (due to excessive load or motor stall, resulting in excessive current);
The leakage current protector has tripped (due to damaged motor winding insulation or grounding of the cable sheath).
Motor fault: The motor winding is burned out (due to aging insulation or water ingress, causing a short circuit);
Motor bearings are stuck (due to lack of oil or wear, causing the rotor to stick).

3. Basic Troubleshooting
Use a multimeter to measure the power supply voltage (three-phase voltage should be within 380V ± 5%) and check the terminals for tightness and signs of burns.
Check the status of the overload protector/circuit breaker. If tripped, first check the load (for example, whether there is a brick stuck in the mold) and then reset it for testing.
After powering off, rotate the motor shaft. If it feels sticky, disassemble and inspect the bearings. Use a megohmmeter (megohmmeter) to check the insulation resistance of the motor windings (normally, it should be ≥ 0.5MΩ; if it is lower, the windings require repair).
II. Control Circuit Fault: Unresponsive Buttons/Switches
1. Symptom
When operating function buttons such as "Material," "Press," and "Demolding," the equipment does not operate (for example, the cylinder does not extend or retract, or the conveyor belt does not rotate).
The touchscreen/control panel displays normally, but commands cannot be issued.
Even after resetting the emergency stop button, the equipment still does not resume operation. 2. Core Causes
Control component damage: Oxidation of internal contacts of pushbutton switches (poor contact due to long-term use), burnt-out of intermediate relay/contactor coils (no energization);
Line break/short circuit: Control cable sheath damage due to vibration or friction (e.g., cables near moving parts of the equipment), or loose connectors (e.g., PLC output terminals, relay wiring);
PLC failure: PLC (Programmable Logic Controller) input/output module damage (no signal output), or program loss (due to power outage or interference).
3. Basic Troubleshooting
When pressing a function button, observe whether the corresponding relay/contactor engages (listen for a "click" sound). If not, use a multimeter to measure the voltage across the button (normally, it should be on and off) and the coil voltage (to ensure it is within the rated voltage).
Inspect the control cables for obvious damage, focusing on cables near moving parts of the equipment (e.g., near the demolding cylinder).
If the PLC has no output, check the I/O status on the touchscreen (to see if the input signal is normal and the output is active). If the program is lost, contact the manufacturer for a re-install.