1. Problem description and scope
This instruction is intended to solve continuous cases of disconnection of the safety system in industrial devices. Continuous outages can occur in many types of equipment, including industrial units, production lines, and automated systems. In other words, this problem is considered critical because it can lead to production stoppage, risk of injury and loss of production.
2. Network measures
Use protective equipment against harmful factors (PPE): glasses, gloves, protective suit, apparatus for measuring electrical parameters.
Lockout and label energy sources: Before doing anything, ensure that the power supply is turned off and label the switches.
Check for stored energy: storing energy in electromagnets, capacitors, or hydraulic systems can cause injury.3. Necessary diagnostic tools
Name of the tool Model/specification Measuring range The goal Multimeter Fluke 87V 0–2000 V, 0–200 A, 0–20 MΩ Measurement of voltage, current, resistance Optical vibration analyzer Keysight 35670A 0–100,000 Hz Determination of vibration characteristics Thermal camera FLIR T1030sc –20°–550° C Determination of temperature anomalies Signal generator Rigol DG4062 0–200 MHz Testing electrical circuits 4. First assessment: checklist
Point action 1 Check the condition of the safety system and electrical circuits before performing diagnostics. 2 Record recent changes to the equipment (e.g. installation of new sensors, configuration change). 3 Record the history of alarms and messages from the security system. 4 Check the condition of cables and connectors for wear, misalignment or corrosion. 5 Record the temperature, vibration and humidity values in the area of the safety system. 5. Systematic diagnostic scheme
- Symptom: Security outages occur continuously.
- Check: if the security system is disabled during operation or after shutdown.
- If disconnection occurs during operation: check cable interface and electrical connections.
- If shutdown occurs after shutdown: check electrical circuit and backup power.
- Diagnosis: measure the current and voltage at the input and output terminals of the relay system.
- If the values are out of range: check the ground and measure the integrity resistance.
- If the value is within: check cable connections and sensors.
- Symptom: Shutdown occurs in a certain way (for example, after starting the device).
- Check: if there is a disconnection after connecting the electricity.
- If it happens: check the output contacts and sensors.
- If not: check input contacts and power.
- Diagnosis: measure vibration and temperature in the area of the security system.
- If values are out of range: check vibration parameters and grounding.
- If the value is within: check the electrical circuit and sensors.
6. Matrix of causes of defects
Symptom Possible cause (with matching) Diagnostic test Expected value Continuous outages 1. Incorrect sensor settings Measure the distance between the sensor and the object The minimum distance is 10 mm 2. Improper grounding Measure the ground resistance The maximum resistance is 4 ohms 3. Displacement of cables Check the cable connections No displacement 4. Electromagnetic disturbances Measure the noise on the input circuits The maximum noise is 50 dB 7. Analysis of the main causes of defects
7.1. Incorrect sensor settings
Improper sensor setup can lead to continuous outages. For example, the sensor may detect a distance less than the minimum, which causes a shutdown. This may be due to remote installation of the sensor, vibration or changing operating conditions. To confirm, measure the distance between the sensor and the object and check the deviation.
7.2. Improper grounding
Improper grounding can lead to intermittent shutdowns due to electromagnetic disturbances or incorrect voltage measurement. Measure the ground resistance and check that it does not exceed 4 ohms. If the value is greater than 4 ohms, an unsatisfactory ground trip occurs.
7.3. Displacement of cables
Displacement of the cables can lead to loss of contact or interference in the electrical circuit. Check the cable connections for displacement, corrosion, or a loose connection. If an offset is detected, a trip occurs due to the lack of a stable electrical connection.
7.4. Electromagnetic disturbances
Electromagnetic disturbances can lead to continuous trips due to noise on the input circuits. Measure the noise on the input circuits and check that it does not exceed 50 dB. If the value exceeds 50 dB, there is a shutdown due to electromagnetic disturbances.
8. Step-by-step correction procedures
8.1. Correcting incorrect sensor settings
- Check: the distance between the sensor and the object. The distance should be at least 10 mm.
- Set the: sensor at a distance of 10 mm from the object.
- Check: measure the distance after installation.
- Finish: measure the distance and make sure it is within 10mm.
8.2. Correcting improper grounding
- Check: ground resistance. Measure the ground resistance.
- Install: ground if resistance exceeds 4 ohms.
- Check: ground resistance after installation.
- Finish: measure the ground resistance and make sure it does not exceed 4 ohms.
8.3. Correction of misalignment of cables
- Check: cable connections for displacement, corrosion or lack of a stable connection.
- Replace: cable connections if misalignment is detected.
- Check: cable connections after installation.
- Finish: check the cable connections and make sure they are stable.
8.4. Correction of electromagnetic disturbances
- Check: noise on input circuits. Measure the noise on the input circuits.
- Install: filters or insulation if noise exceeds 50 dB.
- Check: noise on input circuits after installation.
- Finish: measure the noise on the input circuits and make sure it does not exceed 50 dB.
9. Preventive measures
The main reason Preventive strategy Control method Recommended interval Incorrect sensor settings Semi-automatic adjustment of sensors Distance measurement Annual Improper grounding Regular grounding check Measurement of grounding resistance monthly Displacement of cables Regular inspection of cable connections Visual inspection monthly Electromagnetic disturbances Installation of filters and insulation Measurement of noise on input circuits Annual 10. Production components and spare parts
Description of the spare part Specification When to replace UNITEC-D category Security sensor Voltage 24 V, current 10 mA After 10,000 cycles or 2 years UNITEC-D 5201 Power cable The minimum distance is 10 mm After displacement or corrosion UNITEC-D 5202 Relay system Voltage 24 V, current 10 mA After 10,000 cycles or 2 years UNITEC-D 5203 Electromagnetic disturbance filter Voltage 24 V, current 10 mA After 10,000 cycles or 2 years UNITEC-D 5204 For all spare parts and components, go to our e-catalog: https://www.unitecd.com/e-catalog/
11. Referral
- CE and UkrSEPRO certification
- DSTU, EN, ISO standards
- Original manufacturer's instructions
- UNITEC-D Technical Support Manual Series
