One of the most common uses for thermal imaging Camera is the regular thermal surveys as part of electrical equipment maintenance. As uninterrupted, quality electricity supply remains at the core of today’s industrial activities, it becomes essential to make the required electrical equipment available all the time, thereby helps in eliminating the factory downtime. Thermal imaging cameras, also known as infrared (IR) cameras, play an important role in such critical application areas.
Thermal imaging cameras work by converting emitted radiation levels into a two-dimensional picture that highlights contrasting energy levels. Electricity generates heat while passing through resistant components. So, in case of any electrical fault, a thermal imaging camera displays a rise in temperature which serves as the basis for identifying most electrical faults.
The prime advantage of thermal imaging camera is that it enables accurate inspection of electrical equipment without interrupting the machine operation. This allows a user carryout preventive maintenance without causing any downtime.
Importance of thermal imaging in electrical industry
Most of the industries are adopting to proactive way of doing maintenance rather than reactive maintenance. Thermal imaging is one of the proven ways of proactive maintenance as it provides insights on heat map of critical electrical assets. No machine goes to fail overnight and the machine always takes a journey from potential failure to actual failure over a period of time. Proactive maintenance is all about finding this journey of the machine towards failure and avoid such failure. According to P. Sridharan, Product Manager, Fluke Technologies (India) Pvt Ltd, thermal imaging is an easy and effective way to understand this journey of the machine by monitoring the thermal image of the machine. He said, “Many electrical problems like single phasing, high resistance contacts, issues related to insulation damage, winding failure of the motor can be identified using thermal imaging in less than a minute. These problems can lead to costly downtime, machine failure and in many instances, safety hazards.”
Discussing the importance of thermal imaging in electrical industry, TP Singh, Sales Director – Emerging Markets-Ins (India, Middle East, CIS, Turkey, SS Africa), FLIR Systems, said, “Globally, including India, electrical utilities are amongst the major users of thermal imaging cameras. Whether generation, transmission or distribution – all use and need accurate thermal cameras as electrical utilities face frequent problem of critical installations getting heated up. The moment this heating phenomenon starts, temperature starts rising and FLIR Thermal imaging cameras play a very important role there. Without touching or taking shut down, these FLIR Thermal Cameras can accurately measure the temperature of these installations from a safe distance.” He further claims, from nut/bolt on a transmission tower to transformers to many other critical installations, FLIR products meet and exceed all expectations.
Types of electrical equipment Thermal Imaging Cameras can survey
The applications of thermal imaging cameras are limitless, said P. Sridharan of Fluke Technologies (India) Pvt Ltd. He adds, “Since thermal imaging cameras help to understand heat map of electrical assets, it is important to include all assets in the thermal imaging survey. The commonly inspected equipment include but not limited to are: (3-phase) Power distribution, fuse boxes, cables and connections, relays/switches, insulators, capacitors, substations, circuit breakers, controllers, transformers, motors and battery banks.”
The inspection is critical during installation and whenever a fault is repaired. Apart, a periodical survey also helps. The success of thermography lies in the ability to compare or trend to arrive at conclusion of the risk of prematurely failing assets. “There is a need to develop a baseline when the equipment is in perfectly healthy condition and compare the thermal image taken at different timeframe with this baseline. The change in the thermal pattern will then reveal a potential problem the asset may undergo,” Sridharan suggests.
TP Singh of FLIR Systems sums up a list of electrical applications that can be surveyed by thermal imaging cameras:
- Checking transformer health which is critical equipment in any substation.
- Predictive maintenance of other critical installations including:
– Inspection of connectors (which are everywhere)
– Inspection of cables and joints
– Inspection of exposed cables.
- Visualisation of SF6 leakage.
A few advanced Thermal Imaging Cameras
Fluke offers wide range of thermal imaging camera that suits different needs and different budgets. Their solutions include a cost-effective pocket size thermal imager to a high-end HD thermal imager. The pocket size thermal imager helps the user to quickly scan the electrical system where he is working for a potential heat map to understand the condition of the machine. The asset tagging feature helps the user to tag the thermal image automatically to the corresponding asset using a barcode. The high-end HD thermal imager has an infrared resolution of 1024 X 768 pixel. With super resolution feature this resolution can be enhanced to 4 times (2048 X 1536 pixel). The product also provides 32x digital zoom.
Fluke also provides a thermal imaging camera with SF6 gas leak detection option. This helps the user to use it in the normal mode for his day to day thermography and in SF6 mode to detect SF6 leak from the circuit breakers, informs Sridharan. He adds, “We also have thermal multimeter that combines a digital multimeter, 2500A clamp meter and a thermal imager in a single tool.”
FLIR has many products being accepted by Indian electrical Utilities but T series has been very successful due to its very useful design, claims TP Singh. It has rotatable optics. T6xx and T1 K has 120-degree rotation and new T5xx has 180-degree rotation of optical block. Since many electrical installations which need to be scanned for temperature are above eye level, this design is very useful. Benefit of this design is, operator does not get stress on wrist, shoulder, neck and eyes while using this range even if this is used frequently. “The ease of use of this great design can be felt only with experience,” assures Singh.