In industrial sites, veteran electricians often rely on their rich experience to quickly locate transmission control circuit faults through simple “Ask, Smell, Listen, Touch” methods. This method is not only efficient, but also solves 80% of common problems. Here are the specific steps:
1. Ask: Ask the operator
- Understand the fault phenomenon:
- Ask the operator about the specific situation when the fault occurred, for example:
- Did the machine stop suddenly?
- Are there any abnormal alarms or indicator lights on?
- Are there any abnormal sounds or vibrations before the fault occurs?
- Understand the frequency and pattern of the fault, for example:
- Is it the first time or is it recurring?
- Does it occur under specific operation or load?
- Get background information:
- Ask if the equipment has been repaired or modified recently.
- Understand the historical fault records of the equipment.
2. Smell: smell electrical appliances
- Check for burnt smell:
- Get close to the electrical cabinet or equipment and smell carefully for burnt or burnt smells.
- If there is a burnt smell, it may be due to the following reasons:
- The motor, cable or terminal block is overheated and burned.
- The contactor, relay or circuit breaker is burned.
- The circuit board or electronic components are damaged.
- Key inspection areas:
- Key components such as motors, inverters, PLCs, contactors, etc.
3. Listen: Listen to the machine sound
- Normal sound:
- Be familiar with the sound of the equipment when it is operating normally, such as the sound of the motor running, the sound of the relay closing, etc.
- Abnormal sound:
- Check for the following abnormal sounds:
- The motor makes a buzzing or irregular noise (maybe a phase loss or bearing damage).
- The contactor or relay makes an abnormal closing sound (maybe the contact point is poor).
- The inverter or drive sounds an alarm (maybe overload or parameter setting error).
4. Touch: Touch the device temperature
- Check whether the temperature is normal:
- Touch the device housing gently with the back of your hand to feel whether the temperature is abnormal.
- The motor, inverter, transformer and other equipment will have a certain temperature during operation, but it should not be hot.
- If the temperature is too high, it may be due to the following reasons:
- Motor overload or poor heat dissipation.
- Loose terminals cause increased contact resistance.
- Cooling fan failure or poor ventilation.
- Key inspection areas:
- Motor housing, cable connector, contactor, circuit breaker, PLC module, etc. Look for maintenace spare parts,go to promaintsupply.com/
5. Comprehensive judgment
- Through the information obtained by “asking, smelling, listening, and touching”, experienced electricians can quickly judge the approximate scope of the fault:
- If it is a burnt smell, focus on checking whether the electrical components are burned.
- If it is an abnormal sound, focus on checking the motor, contactor or inverter. – If the temperature is too high, focus on checking the load, heat dissipation or wiring problems.
6. Simple treatment
- If obvious problems are found, you can try simple treatment:
- Re-tighten the loose terminal.
- Replace the burnt fuse or contactor.
- Clear the blocked cooling fan or vents.
7. Use instruments to check
- If the problem cannot be solved by “asking, smelling, listening, and touching”, use instruments for detailed inspection:
- Use a multimeter to measure voltage, current and resistance to check whether the circuit is normal.
- Use a clamp meter to measure the motor current to determine whether it is overloaded.
- Use an oscilloscope to check the inverter output waveform to determine whether it is normal.
- Use PLC programming software to monitor the program running status and find logical errors.
Summary
“Ask, smell, listen, touch” is a classic method for veteran electricians to quickly troubleshoot transmission control circuit faults. With rich experience and familiarity with the equipment, 80% of common problems can be solved in a short time. If the problem is complex, it can be further checked with instruments. This method is not only efficient, but also reduces equipment downtime and improves production efficiency.
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Note: When performing the “touch” operation, be sure to ensure that the equipment is powered off or the temperature will not cause burns. Safety first!