While a generator may run smoothly during routine testing, a facility can still be left exposed during an outage. This is because the backup generator is only one part of a larger system.
Transfer switches, switchgear, breakers, panels, lugs, and connection points all help carry power through the facility. If those components are loose, degraded, or overloaded, they can create abnormal heat that increases the risk of equipment failure, fire, or injury.
The use of thermal imaging has become a key part of maintenance for backup power systems because it detects these issues before they turn into a larger problem. This has become increasingly important with the mandate of NFPA 70B, the Standard for Electrical Equipment Maintenance.
Key takeaways:
- Thermal imaging helps identify abnormal heat at electrical connection points before those issues become backup power failures.
- Maintenance teams need safe access points, the right thermal imaging tools, and a process for documenting readings over time.
- Thermal imaging is one part of backup power readiness, along with load testing, voltage verification, transfer switch review, temporary power connection planning, and follow-up documentation.
How Does Thermal Imaging Help Prevent Backup Power Failures?
In backup power systems, heat often starts at connection points. Loose lugs, worn contacts, overloaded components, failing breakers, or connections that have been loosened and retightened during past service can all create heat.
A generator can run smoothly during a routine test, while hidden electrical issues exist elsewhere in the backup power path. Transfer switches, switchgear, breakers, panels, utility mains, transformer mains, and generator output connections are all critical components of the backup power system.
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NFPA 70B changed significantly in recent years. What was once a recommended practice became a formal standard for electrical equipment maintenance, using mandatory language for inspection, testing, documentation, and maintenance planning. The 2026 updated edition of NFPA 70B supports that direction, encouraging facilities to review how they inspect and document the equipment that supports backup power.
Thermal imaging is not required for every backup generator or facility. It becomes required when the facility’s electrical maintenance program calls for thermal inspection, whether through NFPA 70B, an authority having jurisdiction, an insurer, an owner specification, or another adopted maintenance standard.
Backup power system maintenance requires more than confirming that the generator starts during routine testing. Teams also need to regularly inspect electrical connections that support the system under real operating conditions, and thermal imaging makes issues easier to find and document.
What Do Maintenance Teams Need for Thermal Imaging Inspections?
Inspections need three things to be useful in backup power maintenance:
- Safe access to the equipment
- The right thermal imaging tools
- A clear process for documenting and reviewing readings
Thermal imaging uses an infrared camera to detect heat patterns on equipment. In backup power maintenance, heat patterns help technicians identify abnormalities at breakers, lugs, transfer switches, switchgear, generator output connections, and other electrical connection points.
Inspections should happen when equipment is operating under the appropriate load conditions. A generator start-up may confirm that the unit runs, but does not show how the system performs under load. This is why thermal imaging is often tied to load testing, transfer switch testing, and other electrical maintenance work.
Maintenance teams also need a safe way to collect readings. An infrared (IR) window is a fixed inspection point that allows technicians to use an infrared camera or thermal imaging tool to inspect energized electrical equipment without opening the enclosure.
IR windows make inspections safer and more repeatable. They give technicians a consistent access point for checking the same components over time, which also makes documentation easier.
A thermal imaging camera and a thermal gun are not the same tool. A thermal imaging camera shows heat patterns across equipment, while a thermal gun or infrared thermometer provides a point temperature reading.
What Generator Load Testing Should Look Like Now
Code-compliant testing is now expected to be safe, repeatable, and non-damaging. The goal is to test the generator and its main output breaker under load without altering the system, exposing live parts, or creating new failure points in the process.
Code Requirement: Test Without Altering the System
This requirement is driven by NEC 70 expectations for how electrical systems are installed and connected, and reinforced by NFPA 70B maintenance procedures that do not rely on any disassembly or alteration of the existing system.
Load bank testing and temporary power connections should be plug-and-play. No pulling covers, loosening lugs, or disconnecting and reconnecting permanent wiring.
If a test requires disassembly, it is a sign that the system is not set up for compliant operation and testing.
Code Requirement: Verify Absence of Power Before Access
This requirement is most directly tied to OSHA 70E safe work practices, training, and PPE expectations when working on or near electrical equipment.
Before anyone goes into equipment or makes connections, verify absence of power. Voltage test ports support this job flow by allowing verification from outside the enclosure before access.
Confirm safe conditions first, then proceed with the right PPE and trained personnel.
Code Requirement: Thermal Imaging and Documented Results
This requirement is formalized through NFPA 70B, which makes generator or backup power maintenance programs, documentation, and repeatable procedures part of the expectation.
Thermal imaging becomes part of the test. Use infrared (IR) windows, IR guns, or thermal sensors to capture readings under full load of the generator main output breaker and connections, then document and log results as part of the maintenance record. Separate load bank breakers are not allowed because the test must be performed on the main output breaker.
The point is practical. Heat at terminations is an early warning sign of system degradation, and logging makes the work repeatable and defensible.
Build Generator Compliance Into Every Load Test
The industry has moved from field-expedient workarounds to testing that is safe by design. With NEC 70 and 700.3(F), NFPA 70B, and OSHA 70E now more specifically aligned and referenced, generator load testing is expected to be repeatable, documented, and performed without altering the system.
That is what we support at Power Temp Systems. We provide code-aligned, spec-grade power distribution solutions that enable testing and temporary power connections without exposed access to live parts or damage to permanent connections.
Our core offerings include:
If you are upgrading an existing site or designing a new one, build compliant testing capabilities into the electrical system from the start. With these code changes now tied directly to OSHA, there are no loopholes or grandfathering existing systems. Explore our code-compliant connection and testing solutions for your next project.