The Most Dangerous Five Minutes of Maintenance: Opening Energized Electrical Panels for Inspection
- Brian Hall
- 6 days ago
- 5 min read
In many facilities, maintenance technicians routinely open electrical panels to perform inspections, diagnostics, or predictive maintenance tasks. Removing the cover may seem like a simple step in the process, whether it’s done to take measurements, check connections, or perform an infrared scan.
But those first few minutes after opening an energized panel can be among the most dangerous moments in industrial maintenance.
This is because electrical panels, motor control centers, and switchgear often contain energized components capable of producing severe shock hazards and high-energy arc flash events. When the protective barrier of the enclosure is removed, workers may suddenly (and unknowingly) be exposed to energized conductors, causing serious injury or equipment damage if something goes wrong.
This article overviews the little-known dangers lurking within everyday maintenance tasks and the appropriate strategies to minimize them.
Why Opening a Panel Creates Risk
Electrical equipment is designed with enclosures and barriers that help protect workers from accidental contact with energized components. When a panel door is opened or a cover is removed, the barrier is gone.
Potential hazards include:
Shock hazards from exposed energized conductors
Arc flash hazards if a fault occurs while the equipment is energized
Accidental contact with tools or body parts
Dropped objects creating a phase-to-phase fault
Loose or deteriorated connections that may fail when disturbed
Many arc flash incidents occur not during major electrical work, but during routine activities such as inspections, troubleshooting, or testing. Regular arc flash studies produce arc flash and electrical hazard labels informing workers of the correct boundaries and appropriate PPE. Proper electrical training is crucial to ensure workers realize the danger in opening a panel and know safe steps to follow.
Routine Tasks That Require Opening Panels
Maintenance and reliability professionals may come in contact with energized electrical equipment while performing tasks such as:
Infrared thermography inspections
Voltage measurements and diagnostics
Control circuit troubleshooting
Visual inspections of electrical components
Commissioning and startup activities
Because these tasks are common in industrial environments, understanding the risks is crucial. Personnel working energized electrical equipment should be protected from exposure to shock and arc flash hazards via commonsense measures such as following a formal Energized Electrical Work Permit or documented safe work procedure when power cannot be shut off.
The Predictive Maintenance Paradox
When you're implementing infrared thermography and electrical inspections as part of an in-house predictive maintenance program, your goal is to identify problems before they lead to equipment failure.
However, these inspections can introduce risk if they require workers to open energized panels.
For example, thermography can detect:
Loose connections
Overloaded circuits
Deteriorating breakers
Imbalanced loads
These issues are important to identify, but the act of opening the panel itself may expose workers to significant electrical hazards.
This creates a paradox: the inspection designed to improve reliability may also increase worker exposure to electrical energy.
That's why any maintenance worker equipped with an infrared camera should receive comprehensive training, not just on what to look for but also what to do when a hazard is identified. Safe operating procedures must be established and baked into your electrical safety program.
How to Protect Your Workers From Electrical Dangers
Conduct An Arc Flash Analysis
Incident energy, which is the thermal energy released during an arc flash event, varies dramatically from one piece of equipment to the next. One panel in your facility might present a manageable hazard. The panel right next to it could produce energy levels capable of causing severe burns in a fraction of a second.
Without an arc flash analysis, your technicians have no way of knowing the difference. They open the panel blind.
An arc flash analysis evaluates your entire electrical distribution system, calculating fault currents, assessing protective device coordination, determining incident energy at each piece of equipment, and defining the arc flash boundary. The practical output is labels on each piece of equipment telling your workers exactly what hazard exists, what PPE is required, and what approach boundaries apply.
Arc flash studies provide the data needed to:
Label equipment with hazard information
Establish safe approach boundaries
Select appropriate arc-rated PPE
Identify opportunities to reduce arc flash risk through engineering improvements
For maintenance teams performing inspections and diagnostics, this information is essential.
Implement a Robust Training Program
Every label, boundary marking, and PPE requirement depends on a person understanding it and acting on it correctly. That's the role of electrical safety training: building the knowledge and judgment that turns accurate documentation into safe behavior.
This extends well beyond your electrical team. OSHA 1910.332 requires safety training for all employees who face a risk of electric shock, and many serious electrical accidents involve workers who aren't electricians — a facilities worker resetting a tripped breaker, a machine operator near an open panel, a contractor who opens the wrong disconnect.
Electrical safety training based on **NFPA 70E helps workers learn how to:
Identify shock and arc flash hazards
Understand approach boundaries
Select appropriate PPE
Follow procedures for establishing an electrically safe work condition
Determine when energized work is justified
Maintenance and reliability professionals often interact with energized equipment more frequently than anyone else in the facility. Because of this, their ability to recognize hazards and follow safe work practices is critical.
Update Your Safety Processes and Procedures
Establish an Electrically Safe Work Condition When Possible
While de-energizing is the preferred safety baseline, authorized personnel can safely access energized panels by strictly following NFPA 70E boundaries and PPE requirements.
Evaluate the Need for Energized Work
Some diagnostics and troubleshooting tasks require energized equipment. In those cases, organizations should evaluate:
Why energized work is necessary
What hazards are present
What protective measures are required
Use Appropriate PPE
When working around energized equipment, workers may need:
Arc-rated clothing
Insulating gloves
Face shields or arc flash suits
Safety glasses and hearing protection
Personal protective equipment helps protect workers if an incident occurs.
Use Engineering Controls
Facilities can also reduce exposure by implementing solutions such as:
Infrared inspection windows
Permanently mounted thermal sensors
Remote monitoring systems
These technologies allow inspections without opening energized equipment.
A Critical Moment for Maintenance Teams
Opening electrical panels will always be part of maintenance work. The task itself isn't going away, and neither are the hazards behind the cover.
What can change is how prepared your team is for that moment. When hazard data is current and specific to each piece of equipment, when workers are trained to interpret that data and act on it, and when procedures are in place that account for the real risks of energized work, those dangerous five minutes become manageable.
Because sometimes the most dangerous part of maintenance happens before the real work even begins.
If your facility is due for an arc flash analysis, needs to schedule an infrared inspection, or wants to strengthen your team's electrical safety training, Guidant Power can help you evaluate where you stand and what to prioritize next.
70E®, Standard for Electrical Safety in the Workplace®, NFPA 70®, NEC®, and National Electrical Code® are registered trademarks of the National Fire Protection Association, Quincy, MA. All rights reserved. This informational material is not affiliated with nor has it been reviewed or approved by the NFPA.
