What are the most common electrical control system maintenance issues?

We found a very helpful solution to this was IR scans and then an aggressive approach to taking downtime to make the repairs!

Some of the most common problems encountered with electrical control panels: Power Supply Problems: Voltage fluctuations, tripped circuit breakers, or blown fuses are frequent issues faced by electrical control panels. Wiring Faults: Faulty wiring is another common culprit behind control panel issues. Loose connections, damaged cables, or incorrect wiring can lead to: Intermittent faults. Short circuits. Even electrical fires. Component Failures: Control panels consist of various components, including relays, contactors, switches, and PLCs (programmable logic controllers). Regular maintenance and timely replacement of worn-out components are essential to prevent disruptions.

In long-term panels, over the years, a problem with connections lies in the fact that the panel undergoes modifications. Wires are added, relays are added, terminal blocks are added, wireways are overstuffed, labels are not used as in the original design. As a result, those involved in maintenance are overwhelmed with the new look and the unexpected behavior. The quality of the connections (corrosion, breakage, etc.) depends on the moisture/chemical content of the environment. Dust and dirt entering through vents can also cause problems with overheating and corrosion.

One thing I've found that helps, is using crimped ferrules on control wire terminations. This cuts down on the amount of fraying you get in the wiring of new commissions, which in turn, keeps the connection good and limits chances of arcing due to frayed wires. This is one of many techniques I have used to prevent the issue of faulty/no good connection.

Los problemas más comunes en cuanto a sensores y actuadores son: 1) Calibración incorrecta de los sensores. Estos deben calibrarse de forma periódica para asegurar mediciones precisas. 2) Contaminación y suciedad en los sensores. La acumulación se suciedad, polvo y contaminantes en la superficie del sensor afecta su rendimiento. 3) Fallas en los sensores por calidad de energía. Los circuitos del sensor pueden fallar debido a picos, sobrecargas y otros problemas eléctricos. 4) Desgaste mecánico y lubricación inadecuada en los actuadores. Esto puede afectar los rodamientos, piezas mecánicas y engranajes. 5) Vibración excesiva o resonancia. Aislar o corregir los problemas de vibración es necesario para el funcionamiento óptimo del actuador.

In my experience , a control system designed well and implemented well is usually robust and reliable. The component that fails is the field device ie; sensors. It’s the attitude of replacing like for “like” or substitution where most people will experience issues. The reason this occurs is because staff aren’t experienced enough or have the necessary knowledge of their own control systems to know where a sensor or field device can be replaced with a substitute. An example would be where a smart instrument has been linearised to output a corrected value, if the unbeknown maintenance technician simply replaces a sensor and doesn’t consider any local configuration or control systems compatibility (HART addressing etc) that issues will occur.

Use of compatible is sensors is very important. Conflicting sensor signals create need for frequent maintenance. Proper calibration is also very important. Use of calibrated sensors is vital. Regular re-calibration is also important to maintain reasonable torelances. Watchdogs also come in handy to ensure all sensors and sensors are reasonable operation.

Sensors are in the most vulnerable places to get the best information. They are also often interacted with, leading to wear and tear and degradation. The same can be said for actuators, as they are doing most of the work. It is common for operators to blame the software when a system stops working. However, the root cause could be a mechanical failure such as a bad actuator, servo valve, hydraulic cylinder, or incorrect feedback by a sensor. It is important to identify the issues caused by sensor failures in the system so that they can be checked. If you are working with control systems, having proper testing equipment, such as a Fluke 789 process meter for 4-20 mA circuits, is critical.

Controllers and software should always be the least problematic elements of any Control System. If you're having software related issues then the code was never written or commissioned correctly in the first place! PLCs just work. There's automation today still reliant upon 30+ year old PLCs that have never missed a beat. Failure rates are incredibly low and well designed PLC Software will keep running until the cows come home. It's one of the main reasons why obsolescence is such an issue. That widget making machine in the corner of the factory which has ran since 1992 is never a problem....until it stops. Cyber security is a growing concern for networked or connected PLCs, however the vast majority are still stand alone.

Spoiled to using Siemens equipment. To be fair I haven't used much of the newer AB stuff. So my opinion is mostly biased because of that. HMI, WinCC, their drives. Power blips suck no matter the brands you use. Routine backups can be your best friend, both of the project files AND the programming PC. Not much use to have a project file you can't use! Used a lot of older Reliance and GE stuff ages ago, it held up in dirty and hot environments. Still going in some areas. Hard to get parts for some.

Los problemas más comunes en cuanto a controladores y software son: 1) La pérdida de configuraciones y programas debido a la falta de respaldo o backup puede terminar en tiempos de inactividad prolongados. 2) Las vulnerabilidades de seguridad que exponen el sistema a amenazas externas. 3) Las actualizaciones o cambios en el software que terminan en problemas de incompatibilidad con versiones anteriores. 4) Firmware desactualizado en los controladores ya que las actualizaciones tienen correcciones de errores, mejoras de seguridad y nuevas características. 5) Fallos en los componentes electrónicos del controlador como transistores, relés y condensadores que son elementos con mayor probabilidad de falla con el tiempo.

To prevent malfunctions in complex control systems, keeping software and firmware updated and implementing robust cybersecurity measures is essential.

Been through Rockwell PLCs starting with PLC 2s, 5s, and then ControlLogix. They have managed to change with the times to include motion and process control. In the past we used, Reliance Automax, Giddings and Lewis, and Honeywell for those applicactions. We have now standardized to 100% Rockwell with Ethernet communications and finally it allows the technicians to learn just one platform. Granted it still has many levels, but less division of services. Machine functions are more easily integrated from control to HMI.

Los problemas más comunes con respecto a las fuentes de alimentación y puestas a tierra son: 1) Las fuentes de alimentación pueden presentar fallas como cortocircuitos o fallos en los componentes electrónicos. 2) Las variaciones en el voltaje de entrada o salida pueden afectar el rendimiento de los componentes conectados a la fuente. 3) Operar la fuente por encima de su capacidad nominal puede afectar el funcionamiento del sistema por eso se requiere dimensionar la fuente de acuerdo con las características del sistema. 5) Los electrodos a tierra pueden deteriorarse con el tiempo debido a la corrosión y otros factores. 6) La falta de equipotencialidad puede producir diferencias de potencial entre equipos y estructuras.

I have personally seen installations where HV VFD’s were installed and due to a lack of procedures and scrutiny the entire earthing system, harmonic and power factor correction systems weren’t coordinated which resulted in costly ancillary equipment replacement costs. A wholistic approach is required for every aspect of these projects, earthing and grounding are some of the least known electrical subjects however can be the most important.

When supplying control power to PLC components, be sure that it is "clean" power. Either use a power conditioner or isolation transformer prior to your power supply to eliminate the electrical noise that is present in industrial environments. The digital world works much better when we utilize such practices as keeping clean and dirty power separated and making sure all equipment is properly grounded and bonded.

Loose Neutrals or an ungrounded DC negative can make any day a nightmare. Most of the time that can be isolated pretty quick, if it happens well after installation it can catch you off guard though.

One aspect of grounding that is often overlooked, is the grounding of personnel when handling electronic components that are sensitive to ESD. I have witnessed too many technicians that will pull a card out of a very nicely packaged static protective bag with a disposable ground strap in the box and never use it. The analogy I use is the microdamage to the trace from the discharge is equal to the shock damage on a bearing installed with a brass rod and hammer. The machine will run, but the life cycle has been greatly reduced.

Documentation is golden. Wiring and print diagrams can make the job infinitely easier. We don't go to the extent of printing our PLC programs, but I've seen it done. It never fails in my opinion for someone to make a change after the code is printed lol. They almost never match!

Proper documentation and training of site systems and maintenance procedures for equipment, instruments, and devices is critical to reduce downtime at a site. Along with this, technicians understand how things work cutting troubleshooting time down when events arise. Believe me they do, but with proper understanding they become less and less.

Outdated schematics and untrained personnel can turn troubleshooting into a nightmare. If you follow manufacturer recommendations and ensure proper training , that will help to avoid creating new problems while fixing old ones.

Yes this is definable an issue! Nothing more frustrating than having a control issue and someone made a change and did not update the drawings! Or having a control issue and not able to find the proper drawings! This issue is one I found that companies do not want to put the resources to manage! We would mark up drawings and red line them and they would sit in drafting for months without being updated! This causes unnecessary downtime which ends up costing more than if the company would just put resources in place to handle updates!

Los problemas más comunes en cuanto a documentación y formación son: 1) La falta de documentación actualizada sobre el sistema, diagramas eléctricos y manuales de operación puede afectar las operaciones de mantenimiento. 2) La documentación incompleta o no disponible puede dificultar la solución de problemas y el mantenimiento eficiente. 3) La falta de capacitación del personal puede resultar en personal no familiarizado con los procedimientos y equipos del sistema. 4) La rotación del personal sin transferencia de conocimientos puede resultar en pérdida de información y experiencia. 5) La falta de información en seguridad puede afectar el riesgo de accidentes durante las operaciones de mantenimiento.

Control circuit relays, contactors or signal relays often not able to operate correctly. Therefore it is important to have a preventive maintenance to operate the control circuit or simulate the alarms to ensure that the circuitry are working fine.

Failure to update obsolete equipment. Too many companies run equipment until failure resulting in unplanned downtime and lost production. The older the equipment, the longer the downtime and additional engineering cost. Automation software becomes obsolete due to the two-to-five-year life cycle of operating systems and computer hardware. Good luck finding a computer that can run Windows NT or 98 to connect to that old PLC you should have replaced twenty years ago. Obsolete networks like DH+ and RIO worked great in their time but their knowledgebase is quickly retiring from the workforce.

En realidad consideraría es un tema un poco más complejo que definir como falla principal alguno de los puntos mencionados, partiría más desde la minuciosidad dentro del plan de mantenimiento establecido y el régimen de inspección para solventar hallazgos que estén por fuera del estándar técnico exigido por la industria en la que se trabaje, por ejemplo, la pérdida de parámetros de control en VFD o PLC puede obedecer a problemas de actualización de firmware, el pecado no es no actualizar,el pecado radica en no contar con un backup que debería obedecer a una rutina preventiva (la actualización del firmware también), ahora bien, la pérdida de parámetros también podría obedecer a otras novedades que deberían ser corregidas de manera preventiva

Hola con el tiempo fui aprendiendo que si los cables se degradan .las conexiones .se aflojan mas si hay equipos de calentado (resistencias)etc sensores que se da?an no por efecto propio sino por malas regulaciones .por ser lo unico que hay(disponibles ) Pero lo mas da?ino para su funcionamiento es la suciedad un contacto abierto por aislacion te puede hacer acordar de tu familia mas si son circuitos enclavados con habilitaciones de drives etc la otra muy comun que teniamos en la alimenticia eran los roedores cables pelados o cortados por estos animalitos que provocaban sres problemas de falta de se?ales y cortocircuitos .

I/o card life cycle People tend to forget the components on the cards have a life span. With continuous power to the i/o cards the resistors and other components could fail and depending on the system those i/o cards could be obsolete. This could cause critical down time for a system.