Electrical thermography is valuable because it helps find heat problems while equipment is operating under load.

That is also why it can be hazardous.

A thermal camera cannot see through a closed metal panel cover. In many traditional inspections, workers had to open electrical enclosures to scan breakers, bus connections, lugs, terminations, fuses, contactors, transformers or other energized components.

Opening the enclosure may give the camera a clear view, but it can also increase worker exposure to shock and arc flash hazards.

The source JM Test article focuses on this exact problem. It explains that electrical thermographers often inspect energized equipment under load and that removing covers can expose workers to live conductors and arc flash risk.

Infrared windows are one way to reduce that exposure.

They allow the thermographer to scan internal targets through a permanent inspection access point without opening the enclosure during the inspection.

Why Electrical Thermography Is Performed Energized

Electrical thermography works best when equipment is carrying load.

A loose connection, overloaded circuit or failing component may not show abnormal heat when the system is off.

That is why thermography is often used on energized equipment such as:

• Switchgear
• Motor control centres
• Distribution panels
• Main breakers
• Transfer switches
• MCC buckets
• Bus connections
• Transformer connections
• UPS systems
• Data centre power equipment
• Industrial control panels
• Critical process panels
• Electrical rooms

Thermography can help identify:

• Loose connections
• Overloaded circuits
• Failing breakers
• Hot fuses
• Poor terminations
• Unbalanced loads
• Overheating contactors
• Transformer issues
• Motor control problems
• Switchgear hot spots
• Developing electrical faults

The inspection is useful because it can show problems before failure. But if the thermographer must open energized equipment to perform the scan, the inspection itself becomes part of the risk.

The Two Main Hazards: Shock and Arc Flash

Electrical thermography around energized equipment usually involves two different hazards.

Electric Shock

Electric shock risk exists when a worker can contact, or come too close to, exposed energized electrical conductors or circuit parts.

Shock risk depends on:

• Voltage
• Distance
• Body position
• Exposed parts
• Insulation and barriers
• Work procedure
• Worker qualification
• PPE
• Tools and test equipment
• Equipment condition

Arc Flash

Arc flash risk exists when an electrical fault releases thermal energy.

An arc flash can produce extreme heat, pressure, molten metal, noise, light and flying debris.

CCOHS describes the arc flash boundary as the distance where a person without PPE may receive a second-degree burn if an arc flash occurs.

Arc flash risk depends on:

• Available fault current
• Clearing time
• Equipment type
• Working distance
• Voltage
• Maintenance condition
• Task being performed
• Whether covers or doors are open
• Incident energy
• Arc flash label information
• PPE selection

A worker can be outside a shock boundary but still inside the arc flash boundary.

That is why thermography planning must consider both hazards.

Why Keeping Covers Closed Helps

Keeping covers closed during an electrical inspection can reduce exposure.

The source article says leaving panel covers in place helps reduce direct exposure to energized components and supports more repeatable inspections. It also explains that IR access devices allow thermographers to inspect internal targets without removing covers.

Keeping covers closed can help:

• Maintain a physical barrier between the worker and energized parts
• Reduce direct exposure to live components
• Reduce the need to remove and replace covers during the route
• Make repeated inspections more consistent
• Reduce time spent near open energized equipment
• Support safer preventive maintenance routines

This does not mean the work becomes risk-free.

An enclosure with an IR window is still energized electrical equipment. The site still needs a risk assessment, qualified workers, safe work procedures, appropriate PPE and proper training.

What Are IR Access Points?

IR access points are devices installed in electrical enclosures to allow inspection without fully opening the cover.

The source JM Test article describes three broad categories:

• IR ports
• IR panes
• IR windows

These terms should not be treated as interchangeable.

IR Ports

An IR port is a simple access point through the enclosure.

It may allow a thermal camera to view an internal component, but a basic port may not provide the same barrier protection as a properly rated window.

The source article describes an IR port as a simple hole or group of holes that allows thermal scanning but offers no protection in an arc fault.

For Canadian content, avoid promoting simple holes or unrated openings in electrical equipment.

Any access point installed in an enclosure should be selected, installed and approved so that it does not compromise the enclosure rating, equipment certification, arc resistance, environmental protection or AHJ acceptance.

IR Panes

An IR pane is usually a thin optic material that allows infrared radiation to pass through.

The source article describes panes as thin polymer optics that limit direct contact but may not provide the same arc flash protection as a robust window design.

For practical Canadian copy, the key point is this:

Do not select an inspection access device only because it transmits infrared energy.

It must also be suitable for the electrical enclosure, environment, inspection method, arc flash risk, installation requirements and applicable approval requirements.

IR Windows

An IR window is a permanent inspection window installed in the electrical enclosure.

It allows the thermographer to inspect internal equipment without opening the panel.

FLIR describes IR windows as a way to inspect energized electrical systems without opening the enclosure and to help reduce arc flash exposure.

A properly selected IR window may help:

• Keep a barrier between the worker and energized components
• Support on-load thermal inspections
• Reduce exposure during inspection routes
• Improve consistency across repeated scans
• Reduce the need to remove covers
• Support safer condition-based maintenance
• Provide a defined viewing point for repeatable thermal images

JM Test Canada also lists Fluke IR windows, including the FLK-075-CLKT IR window, and describes it as allowing users to perform scans without directly exposing themselves to live components.

IR Windows Do Not Remove Every Hazard

An IR window can reduce exposure, but it does not eliminate the electrical hazard.

The equipment is still energized.

The thermographer still needs to consider:

• Shock boundary
• Arc flash boundary
• Equipment condition
• Arc flash label
• PPE
• Qualified worker requirements
• Site procedure
• Thermography procedure
• Camera setup
• Window condition
• Viewing angle
• Transmission correction
• Safe access
• Emergency procedure

IR windows support safer access. They are not a substitute for electrical safety planning.

CCOHS notes that arc flash risk assessment should identify the hazard, consider likelihood and severity, and determine protective measures, including PPE where required.

Canadian Electrical Safety Context

For the Canadian page, the article should not frame OSHA or NFPA 70E as the governing Canadian requirement.

CSA Z462 is the key Canadian workplace electrical safety standard.

CSA Z462:24 reorganized requirements around establishing an electrically safe work condition, revised the exception when establishing that condition is “not practicable,” added that absence of voltage must be verified at each point of work, and updated arc flash PPE terminology.

Canadian workplaces should also confirm:

• Provincial or territorial OHS requirements
• Federal OHS requirements where applicable
• Authority having jurisdiction expectations
• Employer electrical safety programme
• Site procedures
• Equipment manufacturer instructions
• Arc flash study
• Equipment labels
• Installation requirements
• Inspection procedure

NFPA 70E and OSHA may still appear in US manufacturer literature or customer specifications, but Canadian implementation should be checked against CSA Z462 and applicable Canadian requirements.

Shock and Arc Flash Boundaries for Thermography

Before inspecting energized equipment, the team should understand whether the thermographer will enter any approach boundary.

Important questions include:

• Will the panel remain closed?
• Will an IR window be used?
• Will any cover be removed?
• Are energized parts exposed?
• Is the thermographer inside the arc flash boundary?
• Is the thermographer crossing the limited approach boundary?
• Is the thermographer crossing the restricted approach boundary?
• What PPE is required?
• Is the worker qualified for the task?
• Is a permit or authorization required?
• Is the equipment in normal operating condition?
• Does the inspection increase the likelihood of an arc flash event?

CCOHS explains that shock and arc flash PPE, boundaries, equipment condition, work planning and training are part of arc flash safety work.

The safest thermography route is usually the one that collects useful data while keeping workers as far as practical from exposed energized hazards.

IR Windows and PPE Requirements

IR windows may reduce exposure, but PPE decisions should not be made by assumption.

PPE must be selected based on the actual task and risk assessment.

Consider:

• Arc flash label
• Incident energy
• Working distance
• Arc flash boundary
• Shock hazard
• Equipment condition
• Whether the enclosure remains closed
• Whether the worker interacts with the equipment
• Whether the task increases arc flash likelihood
• CSA Z462 method
• Employer procedure

CSA Z462:24 replaced older “arc flash PPE category” references with “arc flash PPE minimum arc rating” language in the revised table method.

For Canadian content, avoid saying an IR window automatically eliminates PPE requirements.

A better message is that an IR window may reduce exposure and may affect the task’s risk profile, but PPE requirements must still be confirmed through the employer’s electrical safety programme and CSA Z462-informed risk assessment.

Equipment Condition Still Matters

Arc flash risk is affected by equipment condition.

A closed, properly maintained enclosure in normal operating condition is different from damaged equipment with signs of failure.

Do not proceed with routine thermography if equipment shows:

• Smoke
• Burning smell
• Audible arcing
• Loose or missing covers
• Damaged doors
• Severe overheating
• Water ingress
• Corrosion
• Missing hardware
• Evidence of tracking
• Bulging components
• Unusual vibration
• Failed interlocks
• Missing labels
• Unknown fault condition

CSA Z462:24 added guidance on assessing the condition of maintenance of electrical equipment and systems.

If equipment condition is questionable, the inspection plan should stop and be reviewed by qualified personnel.

IR Window Material and Ratings

The source article compares ports, panes and windows, and argues that robust IR windows are the safer choice for energized electrical inspection. It also warns that not all materials that transmit infrared radiation are suitable for permanent installation in electrical equipment.

For Canadian content, the material discussion should stay practical and non-absolute.

When choosing an IR window, confirm:

• Manufacturer rating
• Electrical enclosure compatibility
• Environmental rating
• Arc resistance or arc test information where required
• Optical transmission characteristics
• Supported camera wavelength band
• Window size and field of view
• Installation requirements
• Inspection target visibility
• Certification or listing
• Enclosure integrity after installation
• Site acceptance
• AHJ expectations
• Maintenance requirements

Do not assume that every “IR window” provides the same protection or measurement performance.

Transmission and Measurement Accuracy

No IR window is perfectly transparent to infrared radiation.

The source article explains that reflection, absorption and transmission all affect the thermal reading. It also states that thermographers must account for transmission when interpreting measurements through an IR window.

This matters because the camera is not seeing the target directly. It is seeing the target through an optical material.

To improve measurement consistency:

• Use the correct window transmission setting if required.
• Follow the window manufacturer’s instructions.
• Use the same viewing point for repeated inspections.
• Use the same camera settings where possible.
• Document the inspection conditions.
• Keep the window clean and undamaged.
• Compare trend data from the same inspection route.
• Understand that qualitative and quantitative inspections may have different requirements.

For trend-based maintenance, consistency matters as much as the absolute number.

IR Windows and Inspection Repeatability

One major benefit of IR windows is repeatability.

If the same target is scanned through the same window from the same position each time, the thermographer can compare changes over time more effectively.

This helps identify:

• Connections getting hotter
• Load-related changes
• Developing faults
• Repaired issues
• New hot spots
• Seasonal changes
• Equipment deterioration

Repeatability also helps with reporting.

A thermography route can be designed around known targets, labelled windows and consistent inspection points.

Where IR Windows Are Most Useful

IR windows are most useful where energized inspections are repeated regularly and opening equipment creates avoidable exposure.

Common applications include:

• Main switchgear
• Distribution switchboards
• Motor control centres
• MCC buckets
• Transfer switches
• UPS cabinets
• Data centre power equipment
• Industrial control panels
• Critical process equipment
• High-value production assets
• Electrical rooms
• Transformer connections where applicable
• Utility and facility infrastructure

They are especially useful when:

• Equipment must remain energized under load
• Inspections are repeated on a schedule
• Open-door inspection creates unnecessary exposure
• PPE makes the inspection slow or difficult
• The same targets must be trended over time
• Access is limited
• Reliability documentation matters

Installation Considerations

An IR window is a modification to an electrical enclosure.

That should be treated carefully.

Before installing an IR window, confirm:

• Equipment manufacturer guidance
• Window manufacturer guidance
• Enclosure rating
• Arc-resistant equipment rating if applicable
• Environmental rating
• CSA / UL / listing requirements where applicable
• AHJ or electrical safety authority expectations
• Engineering review requirements
• Clearance and target visibility
• Window location
• Drilling or cutting procedure
• Debris control
• De-energization requirement
• Lockout requirement
• Re-labelling or documentation
• Inspection route updates

If the enclosure is modified incorrectly, the window may compromise the equipment instead of improving the inspection process.

IR Windows in New Equipment vs Retrofit Projects

IR windows can be considered during new equipment specification or added later as a retrofit.

New Equipment

For new equipment, IR windows can be planned into:

• Switchgear design
• MCC layout
• Panel access strategy
• Maintenance route
• Arc flash risk management
• Asset management records

This usually allows better placement and easier approval.

Retrofit Projects

For retrofit installations, more checks may be needed.

Confirm:

• Existing equipment rating
• Safe de-energization plan
• Internal clearance
• Enclosure modification approval
• Target visibility
• Warranty impact
• Certification impact
• AHJ expectations
• Installation procedure
• Updated drawings and labels

Do not install an IR window as an informal field modification without checking the electrical and certification implications.

IR Windows vs Opening the Panel

Opening the panel may provide a clearer view, but it can also increase exposure.

IR windows may reduce exposure, but they require planning and proper installation.

The best option depends on the equipment, risk assessment, inspection target and site procedure.

Thermographer Training Still Matters

An IR window does not make anyone automatically qualified to inspect energized electrical equipment.

The thermographer should understand:

• Camera operation
• Focus
• Emissivity
• Reflected temperature
• Window transmission
• Load conditions
• Distance and angle
• Thermal patterns
• Electrical component behaviour
• Shock and arc flash boundaries
• PPE requirements
• Site access rules
• Stop-work conditions
• Reporting requirements

A qualified electrician may also need thermography training to capture reliable thermal data.

A trained thermographer may need a qualified electrical worker present to support energized equipment access.

What to Document in an IR Window Thermography Programme

A useful programme may include:

• Asset list
• Window location
• Internal targets visible through each window
• Window manufacturer and model
• Installation date
• Enclosure ID
• Equipment rating
• Inspection frequency
• Camera model
• Camera settings
• Transmission correction
• Load condition
• Baseline images
• Route instructions
• PPE requirements
• Stop-work criteria
• Cleaning and maintenance process
• Reporting format
• Corrective action workflow

Good documentation turns IR windows from a hardware purchase into a repeatable inspection system.

Common Mistakes to Avoid

Assuming an IR Window Eliminates Arc Flash Risk

It does not. It can reduce exposure, but the equipment is still energized.

Assuming PPE Is No Longer Required

PPE must be selected based on the risk assessment, arc flash label, CSA Z462 method and employer procedure.

Installing an IR Window Without Engineering Review

A poor retrofit can affect enclosure integrity, certification, arc resistance or environmental rating.

Ignoring Transmission Correction

Thermal readings through a window are affected by the optic. The source article explains that transmission, reflection and absorption must be considered.

Choosing Window Size Without Checking Targets

The window must allow the thermographer to see the components that matter.

Forgetting to Clean and Inspect the Window

A dirty, scratched or damaged window can affect image quality and measurement consistency.

Treating All IR Access Devices the Same

Ports, panes and windows do not provide the same level of protection or performance.

Copying US Compliance Language to Canada

Replace OSHA/NFPA-as-law language with CSA Z462, Canadian OHS, AHJ and employer-procedure language.

JM Test Systems Canada Support

JM Test Canada lists thermal imagers and IR thermometers from brands such as Fluke, FLIR, Fotric and SEEK. The Canadian catalogue also lists IR window products such as the Fluke FLK-075-CLKT and Fluke CV400, with availability varying by item.

JM Test Canada’s rental page states that its rental division includes electrical test equipment and other test-equipment categories for Canadian customers.

For this Canadian article, keep the CTA conditional.

Customers should confirm:

• IR window availability
• Thermal camera availability
• Rental or purchase options
• Window size
• Electrical enclosure compatibility
• Installation requirements
• Camera compatibility
• Transmission correction requirements
• Calibration documentation where needed
• Shipping timeline
• Current Canadian stock

Practical Takeaway

Electrical thermography helps identify developing electrical problems before they become failures.

But if an inspection requires energized electrical equipment to be opened, the inspection can expose workers to shock and arc flash hazards.

IR windows can help by allowing thermographers to inspect energized equipment through a permanent access point while keeping the enclosure closed. FLIR describes IR windows as a way to inspect energized electrical systems without opening the enclosure and to help reduce arc flash exposure.

For Canadian workplaces, the safest approach is not simply “install windows and inspect.”

The better approach is:

• Assess shock and arc flash hazards.
• Follow CSA Z462-informed procedures.
• Confirm PPE requirements.
• Keep covers closed where practical.
• Select properly rated IR windows.
• Install them correctly.
• Account for transmission.
• Train thermographers.
• Document inspection routes.
• Maintain and inspect the windows.
• Confirm Canadian product availability and site requirements before buying or installing.

JM Test Systems Canada can support thermal imaging and IR window needs where available. Confirm the exact product, compatibility, ratings, accessories, rental options and Canadian service details before booking.