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Condition Monitoring for Electrical Systems: What Reliability Teams Need to Know

Written by Luke Grice-Lowe | July 29 2026

TL;DR

Electrical systems in MCCs, PLC cabinets, VFDs, and switchgear begin degrading long before a breaker trips or a PLC logs a fault. Continuous condition monitoring helps reliability teams detect thermal anomalies, electrical instability, and developing faults earlier through:

  • Continuous thermal monitoring

  • Electrical signature analysis

  • Current variability tracking

  • Multi-signal correlation 

This gives maintenance teams earlier visibility into degradation, helping reduce unplanned downtime, emergency troubleshooting, and operational disruption.  

What Signals Indicate Electrical Degradation 

Electrical infrastructure produces measurable signals before failure.


Localized thermal rise at a fuse holder and bus bar inside an MCC cabinet signals high-resistance connections, a common precursor detected through condition monitoring of electrical equipment.

Current signature changes at the motor level include 5–10% variability under stable load, minor voltage imbalance, and incremental amperage rise. And acoustic emissions and partial discharge further indicate arcing and insulation stress within energized infrastructure. 

Conveyor motor supplied by a VFD showing current variability trends captured by a motor condition monitoring system for early electrical fault detection.

Continuous thermal condition monitoring can capture this trend even when the PLC has not logged a fault.  

Condition Monitoring Techniques for Electrical Equipment

Effective condition monitoring of electrical equipment combines thermography, ultrasound monitoring, partial discharge detection, and electrical signature analysis.

Power condition monitoring identifies voltage imbalance, harmonic distortion, and current instability affecting motor-driven systems. 
 
Each technique captures a different failure precursor. Together they improve diagnostic clarity. 

Continuous vs. Periodic Monitoring 

Periodic inspections using handheld thermal cameras capture a snapshot in time. 
 
Continuous monitoring using fixed thermal cameras captures progression under live load and peak throughput conditions. 
 
Since electrical degradation is load-dependent and time-dependent, continuous condition monitoring preserves the degradation curve and buys reliability teams time to act, before threshold-based alarms trigger and functional failure shuts down a line. 

Case Study: Thermal Rise in an MCC Detected Before Peak Shift Failure 

At a high-throughput fulfillment center, one conveyor zone drew all its power through a single MCC cabinet. On paper, everything looked fine: no PLC faults had been logged, and the last periodic infrared route came back clean. That's exactly the kind of gap continuous monitoring is built to close, because a snapshot inspection can miss a fault that's still building. 


An 11–13°C temperature delta at a breaker termination inside an MCC indicates a developing high-resistance connection detectable through continuous electrical condition monitoring.

Continuous thermal monitoring painted a different picture. It picked up:

  • An 11°C temperature delta at a breaker termination

  • A gradual 6% increase in motor current variability over time 

Instead of waiting for an alarm or a hard failure, the team scheduled an inspection during planned downtime to check out the signal. What they found was a high-resistance lug connection that had started to discolor, alongside early-stage insulation degradation - the kind of developing fault that doesn't show up cleanly on a single inspection route but builds steadily in the data over time.

Because they caught it early, the fix was straightforward. The team completed the repair in 45 minutes, avoided a breaker trip during the peak shift window, and saved an estimated $18K in unproductive labor costs that a hard failure at the wrong moment would have caused. 

This is exactly why thermal and vibration are more useful together than either is alone: Each one acts as a check on the other. When a team can see both signals on the same asset, the pattern between them tells a more complete story than either signal would on its own. Corroboration also cuts noise: A single elevated reading on one signal, unconfirmed by the other, gets triaged down instead of dispatching a technician.

Read more about our solutions for distribution and warehousing

What Good Electrical Condition Monitoring Looks Like 

Strategic electrical condition monitoring that helps teams shift from reactive emergency responses to proactive, planned interventions depends on:

1. Always-on visibility inside panels, MCC cabinets, switchgear, and VFD enclosures 
2. Trend-based deviation detection instead of static threshold alarms 
3. Multi-sensor correlation across thermal, current, and mechanical response signals 
4. Validated alerts integrated into CMMS workflows to support planned intervention timing 

Get more insights into how MultiSensor AI solves electrical fault detection for panels, MCCs, and switchgear.  

Closing the Visibility Gap  

If your facility relies solely on periodic thermal inspections with handheld infrared cameras, the question is not whether degradation exists—it is whether you are seeing it early enough. 
 
Continuous condition monitoring provides reliability teams with the real-time data they need to make more informed and proactive decisions, helping them avoid operational disruptions, wasted resources, and potentially catastrophic failures. 

If you’re ready to see how multi-sensing monitoring can help your maintenance and reliability efforts, our team is eager to explain in a quick demo—schedule it here.

FAQs: 

What is condition monitoring for electrical systems?

Condition monitoring for electrical systems is the continuous observation of electrical infrastructure such as MCCs, PLC cabinets, VFDs, switchgear, fuse holders, and bus bars to detect early signs of degradation before failure occurs. It uses techniques such as thermal monitoring, electrical signature analysis, partial discharge detection, and power quality monitoring to identify developing faults under live operating conditions.

Why do periodic infrared inspections miss electrical faults?

Periodic IR inspections capture a single thermal snapshot during a scheduled route or downtime window. Many electrical faults are load-dependent, meaning the heat signature only appears under specific operating conditions. If the fault is inactive during the inspection, the panel may appear normal even though degradation is progressing.

What are the earliest signs of electrical degradation in MCCs and switchgear?

Early indicators include:

  • Localized thermal rise at breaker terminations or fuse holders

  • Increasing motor current variability

  • Voltage imbalance

  • Harmonic distortion

  • Insulation stress

  • Partial discharge activity

  • Intermittent arcing

These signals often develop gradually before alarms trigger or equipment fails.

What equipment should be monitored in electrical condition monitoring programs?

Electrical condition monitoring programs typically focus on:

  • Motor control centers (MCCs)

  • PLC cabinets

  • Switchgear lineups

  • VFD enclosures

  • Fuse holders

  • Bus bars

  • Breaker terminations

  • Conveyor motor systems

These assets commonly experience load-dependent degradation and thermal stress in high-throughput facilities.

What is the difference between continuous and periodic condition monitoring?

Periodic monitoring relies on scheduled inspections using handheld tools such as thermal cameras. Continuous monitoring uses permanently installed sensors or thermal cameras to track asset behavior under live operating conditions over time.

Continuous monitoring captures degradation trends, intermittent thermal anomalies, and load-dependent faults that may not appear during periodic inspection windows.

How does continuous thermal monitoring help reliability teams?

Continuous thermal monitoring allows reliability teams to:

  • Identify gradual temperature increases

  • Detect high-resistance connections early

  • Track deviation from historical baselines

  • Validate thermal anomalies under real operating load

  • Schedule maintenance before failure disrupts production

This improves planned intervention timing and reduces emergency shutdowns.

What causes thermal hotspots inside electrical panels and MCCs?

Thermal hotspots are commonly caused by:

  • Loose or degraded electrical connections

  • Rising resistance at terminals or lugs

  • Overloaded circuits

  • Voltage imbalance

  • Insulation breakdown

  • Arcing within energized infrastructure

These conditions generate localized heat that progressively worsens if left unresolved.

Why is multi-signal monitoring important for electrical fault detection?

Single-sensor monitoring can create false positives or miss early degradation. Combining thermal data with electrical current trends, vibration behavior, and operating context improves diagnostic confidence.

For example, a slight temperature rise paired with increasing motor current variability is a stronger indicator of developing electrical degradation than temperature data alone.