Rethinking Condition Monitoring for Modern Electrical Infrastructure
Predictive maintenance has become increasingly important in electrical engineering. Advances in sensors, Industrial Internet of Things (IIoT), artificial intelligence and data analytics have made it possible to monitor equipment condition, identify abnormalities earlier and make maintenance decisions based increasingly on actual asset condition rather than fixed schedules alone.
Yet one practical question remains:
Which electrical assets are actually worth monitoring?
The answer is not necessarily “everything”. Condition monitoring is most effective when applied strategically to assets whose failure could significantly affect safety, operations or business continuity. Collecting more data does not automatically produce better outcomes. The objective should be to obtain useful information that allows engineering and maintenance teams to make better decisions.
Start with Criticality, Not Technology
Rather than beginning with the question of which sensors or monitoring systems to install, organisations should first determine which assets are most important to their operations.
- Would failure result in production or operational downtime?
- Could it create a safety risk?
- Would repair or replacement require a significant shutdown?
- Is the asset expensive or difficult to replace?
- Does it have a history of recurring problems?
- Can deterioration be identified before failure occurs?
A criticality-based approach helps focus maintenance and monitoring resources where they can provide the greatest operational value.
Which Assets Should Be Considered?
Different assets require different approaches. For some, continuous condition monitoring may be justified. For others, periodic inspection, testing or calibration may provide sufficient information.
Power Transformers
Transformers are often among the most critical assets in an electrical distribution system, with unexpected failure potentially resulting in prolonged outages and significant operational disruption.
- winding and oil temperature
- loading profile
- dissolved gas analysis (DGA)
- moisture content
- insulation condition
- cooling system performance
- partial discharge activity, where applicable
The aim is to build a clearer picture of the transformer condition so that maintenance can be planned before deterioration develops into failure.
Switchgear, Switchboards and MCCs
HV, MV and LV switchgear, switchboards and Motor Control Centres (MCCs) form essential parts of electrical distribution and equipment control.
- Infrared thermography
- Temperature monitoring
- Humidity monitoring
- Partial discharge detection where applicable
- Breaker operation counts
- Contact resistance testing
- Power quality analysis
- Functional testing
Abnormal temperatures, deteriorating connections and other developing conditions can often be identified before they result in equipment failure or an unplanned shutdown.
Motors and Variable Speed Drives
For critical motors, parameters such as vibration, bearing and winding temperature, current characteristics, insulation condition and alignment can provide useful indications of developing electrical or mechanical problems.
- For Variable Speed Drives (VSDs), relevant parameters can include internal temperature, cooling performance, harmonic distortion, DC bus condition, capacitor health, fault history and load profile.
Where production or building systems depend heavily on motor-driven equipment, identifying deterioration early can reduce operational disruption.
UPS Systems and Generators
Backup-power systems need to be ready when the normal supply is unavailable.
- For UPS systems: battery condition, temperature, charger and inverter status, loading and available runtime.
- For generators: periodic inspection, functional testing and load-bank testing to verify their ability to perform when required.
Busbars, Busduct and Cables
Electrical distribution infrastructure such as busbars, busduct systems and cables may not require continuous monitoring in every application.
- Visual inspection
- Thermography
- Torque checks for applicable connections
- Periodic electrical testing
The objective is to identify overheating, connection issues or deterioration before they affect system reliability.
PLCs, Control Panels and Instrumentation
Modern facilities increasingly depend on control and instrumentation systems alongside traditional electrical assets.
- PLC and control panels: routine inspection, temperature and power-supply checks, I/O diagnostics and preventive maintenance.
- Instrumentation: periodic calibration, loop checking, functional testing and visual inspection.
- Critical process instruments: calibration and preventive maintenance according to manufacturer and process requirements.
- Remote I/O and communication networks: periodic inspection and network diagnostics, particularly where reliable communication is essential to control and monitoring systems.
Different Assets Require Different Maintenance Strategies
There is no single monitoring strategy suitable for every asset.
| Asset | Typical approach |
| Distribution boards / MCCs | Routine inspection, thermography and functional testing |
| Power transformers | Continuous or periodic condition monitoring depending on criticality |
| Critical motors | Vibration and temperature monitoring |
| HV/MV/LV switchgear | Periodic testing with targeted online monitoring |
| Cables | Inspection, thermography and testing where appropriate |
| Generators | Periodic inspection, functional testing and load-bank testing |
| Busbars / busduct | Visual inspection, connection checks and thermography |
| UPS systems | Continuous battery and operating-status monitoring |
| PLC / control panels | Routine inspection, temperature and power-supply checks, I/O diagnostics |
| Instrumentation | Calibration, loop checks and functional testing |
| Critical process instruments | Calibration and preventive maintenance based on process and manufacturer requirements |
| Remote I/O / communication networks | Periodic inspection and network diagnostics |
Apply the right monitoring or maintenance method to the right asset.
Turning Data into Engineering Decisions
Installing sensors does not by itself create a predictive maintenance programme. Condition data becomes useful only when it supports action. Effective monitoring therefore requires:
- meaningful alarm thresholds
- an understanding of normal operating conditions
- engineering interpretation of abnormal trends
- integration with maintenance planning
- follow-up investigation where abnormalities are identified
Artificial intelligence and advanced analytics can increasingly help identify patterns within large volumes of operating data. However, engineering judgement remains essential in determining whether intervention is required and what action should be taken.
Technology should support engineering expertise—not replace it.
Looking Ahead
As industrial facilities become more connected, condition-based maintenance will continue to play an important role in electrical and EICA asset management.
The opportunity is not simply to monitor more equipment. It is to understand which assets matter most, determine what information is genuinely useful, and apply an appropriate combination of monitoring, inspection, testing and calibration.
Rather than asking:
“How can we monitor more equipment?”
a more valuable question may be:
“Which assets will provide the greatest operational benefit if we understand their condition better?”
That is often the better starting point for an effective asset-monitoring strategy.