Understanding the Importance of Circuit Breaker Maintenance

Understanding the Importance of Circuit Breaker Maintenance

 

Why Circuit Breaker Maintenance Matters

Circuit breakers are the unsung heroes of your electrical system. They're designed to trip instantly during fault conditions — like a short circuit or overload — to prevent catastrophic damage while keeping workers safe.

But what happens if a breaker doesn’t operate as designed?

That’s not just a theoretical concern. Circuit breakers, like any mechanical device, require maintenance. If they fail to trip, the result can be devastating — especially when it comes to arc flash.

 

Real-World Example: What Happens When Breakers Fail?

We created the following Arc Flash Critical Analysis to visualize how circuit breaker condition directly affects worker safety. 

We conducted an arc flash study where we analyzed 800 pieces of equipment with their protective devices operating as intended. 

We then determined the results if the protective devices failed to operate, and created a bar chart to help visualize and understand the effects. 
 

What You’re Seeing:

The top bar shows incident energy (IE) levels when protective devices work properly.
The bottom bar shows incident energy if the protective devices fail to operate (we limited the fault clearing time to 2 seconds).

When the protective devices are functioning properly, most arc flash hazard levels are in the lower range (<12 cal/cm²).

When protective devices fail due to lack of maintenance, over 50% of the arc flash hazard levels moved up a hazard category with about 20% of those exceeding 40cal/cm2.

Note: In reality, it is highly unlikely that all protective devices will fail at once, and there will typically be additional protection upstream to catch the fault in the case that a circuit breaker fails to operate, so this is an extreme example. However, that doesn’t mean lack of maintenance will not lead to increased hazards in the real world. 

 

Theoretical Example:

Take for example a typical switchgear setup, with a large main breaker, lets say 1200 amps, and then several smaller circuit breakers feeding loads/panels, typically anywhere between 30-400 amps. 

These small breakers tend to catch the downstream faults very quickly, within fractions of a second. 

If one of these breakers fails to operate due to lack of maintenance, then the main breaker is the only other device you can rely on to catch the fault besides the slow utility fuse.

The main breaker is typically too large to catch these faults within 2 seconds, and this would lead to many of the downstream devices having greatly increased incident energy levels. 

The electrician would not be dressing up in the appropriately rated PPE at that point, which is extremely dangerous. 

 

What the Standard says:

According to CSA Z462 Clause 5.2.5.2, organizations are required to:

•    Identify protective devices in their power distribution system,
•    Evaluate their risk by determining their safety risk factors if they fail to operate,
•    Verify that they are functioning and set as they were designed,
•    Confirm that they are maintained in accordance with the maintenance program requirements. 

Note: This is done to confirm that protective systems and devices are maintained for worker safety to eliminate or reduce the risk of exposure to unsafe conditions such as sustained release of incident energy that could result from an arcing fault.

Failing to follow this standard can leave you exposed — legally and physically.

Note: Although not exactly the same — Standard NFPA 70E: 205.3 under general Maintenance Requirements:

Electrical equipment shall be maintained in accordance with manufacturers' instructions or industry consensus standards to reduce the risk associated with failure. 
The equipment owner or the owner’s designated representative shall be responsible for maintenance of the electrical equipment and documentation.

205.4 Overcurrent Protective Devices. Overcurrent protective devices shall be maintained in accordance with the manufacturers’ instructions or industry consensus standards. Maintenance, tests, and inspections shall be documented.”

Preventative Maintenance Measures:

Whether you’re dealing with molded case, vacuum, low-voltage, or high-voltage breakers, your maintenance approach should include:

•    Inspection & Cleaning: Remove dust, corrosion, and contaminants from housing and terminals.
•    Lubrication: Moving parts (especially in air and vacuum breakers) must operate freely.
•    Functional Testing: Verify the breaker trips as expected under simulated fault.
•    IR Scanning: Identify overheating contacts, loose connections, and early signs of failure.
•    Coordination Check: Confirm the breaker operates within the right sequence and time frame.
•    Settings Verification: Ensure trip units or relays match your latest arc flash study.

This isn’t just maintenance — it’s risk reduction.

 

Maintenance Tips:

Here are a few actionable tips to strengthen your program today:

•    Tag High-Risk Equipment: Use Arc Flash Critical Analysis to identify “must-maintain” breakers.
•    Create an Electrical Equipment Inventory with maintenance intervals per breaker type.
•    Use QR Codes on gear to link maintenance history, test results, and arc flash data.
•    Track Breaker Age: Some molded case breakers are over 30 years old and out of spec.
•    Partner with Experts: Use a qualified contractor or in-house engineering team to validate breaker coordination and update single line diagrams.

 

Final Thoughts

Many organizations don’t know the condition of their breakers — until they fail. By treating breaker maintenance as a critical safety initiative, you shift from reactive to proactive, reducing downtime, liability, and most importantly — risk to your people.

Ready to Build a Maintenance Plan?

At Leaf Electrical Safety, we help you build a maintenance plan that keeps breakers operating as designed.

Want to get started?

Explore our Maintenance Planning Services »

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