A home inspection can incorporate a thermal imaging camera to accompany an electrical systems inspection. Components in electrical systems almost always overheat before they fail, problem areas are more easily and safely found when viewed through an IR (infrared) camera. Thermal imaging allows apparent temperatures to be seen as gradient colors, with hotter spots displayed as brighter colors, and cooler (and wet) spots displayed as darker colors. When a malfunctioning electrical component or connection is generating more heat than it should be, its apparent temperature will make it stand out when viewed through thermal imaging.
During an inspection, electrical equipment, such as distribution panels, switch boards, contacts, transformers, receptacles, and service and control panels, can be examined through a thermal camera. By viewing apparent temperature differences, home inspectors can identify and document problems, such as loose connections and overloaded circuits, which are the most common causes of electrical fires. Other issues, such as transformer cooling problems, induced currents, arcing, and motor-winding faults, also become readily apparent.
Thermal imaging can detect electrical issues that include:
- excessively hot or loose connections;
- overloaded wiring;
- overloaded circuits;
- overloaded transformers;
- overloaded motors;
- arcing; and
- excessive harmonics.
Advantages of a Home Inspector Using an Thermal Camera for Electrical Inspections
Because viewing temperature differences through a thermal camera requires no physical contact, and can cover a lot of space in one sweep, no other technology allows electrical faults to be found as safely and as quickly as thermal imaging. Another important benefit is that it allows problem areas and components to be located before damage from any serious failure or electrical fire occurs. This helps ensure safety. It can also save money that might otherwise need to spent on extensive repairs.
Here’s a list of advantages of using an thermal camera for electrical inspections during a home inspection:
- It’s non-contact, which helps ensure a safe inspection.
- It’s fast and accurate.
- It helps identify problems before they cause serious failure or an electrical fire.
- It’s non-intrusive, so there is no interruption of power during the inspection.
- It can be used as part of inspections that are conducted as preventative maintenance.
- It provides documentation of problems.
Home Inspection Tips
Before beginning the home inspection, it is useful to ensure that access is available to all areas and components that will be inspected. The electrical systems can then be examined while operating under a normal load. Any open panels or enclosures are typically inspected first. A panel that shows signs of moisture, is heavily rusted, is buzzing or arcing, or that generally shows any signs of being unsafe should be reported but not opened or touched. Infrared images can be taken from a safe distance for documentation.
Panels and other areas to be inspected that are deemed safe through visual inspection first, such as receptacles, can be examined by line of sight with the infrared camera. It is quick and easy to view all components in most service panels with thermal imaging, and problem areas will be visible as apparent temperature differences. These areas can then be documented by including an infrared image alongside a standard digital photo in the inspection report. One practice that may be helpful is to document similar components operating under similar loads. The side-by-side comparison of a properly functioning component and a similar one that is not operating correctly is a good way to gather additional details to present clear documentation without exceeding InterNACHI’s Standards of Practice for conducting a safe electrical inspection.
- the exact locations of any problems found;
- a description of the issue that also includes any nameplate data, and phase or circuit numbers;
- copies of thermal images and corresponding visible-light or digital images;
- any information regarding conditions that may affect the results, their repeatability, or the interpretation of the problem found.
- Knob-and-tube wiring that is still live and working
- Aluminum wiring
- Evidence that the electrical has been modified
- Service smaller than 100 amps, fuses for the branch circuits, or a breaker panel older than 40 years. Some older breaker panels have breakers that do not reliably do their intended job due to poor design or age. Some breaker panels deteriorate due to conditions such as dust or high humidity.
- Wall switches that do not control anything. Sometimes fixtures are removed and wires are not capped off properly like they should be.
- Lights in the house that flicker or dim and brighten. This could mean a damaged wire or loose connection.
- Hidden junction boxes. The electrical code says that anytime wires are joined together in a junction box, that the junction box should be accessible and not hidden behind drywall.
- Overloaded fuses of breakers
- Outlets near water sources, outdoors, in garages and unfinished basements that are not GFCI (ground fault circuit interrupter) outlets. A GFCI receptacle will cut off power immediately if there is any leak of electricity out of the circuit.
- Not enough outlets, or outlets that accept only two prong devices. These can lead to overloading of circuits.