Electrical Power & Protection


Using infrared thermometers in electrical maintenance

January 2021 Electrical Power & Protection

Since electrical currents generate heat, checking temperature is an effective method of condition monitoring in electrical systems. Non-contact, infrared thermometers enable such checks to be carried out quickly, efficiently and safely, without the risk of electric shocks or the need to shut down the plant or facility. Typical areas of use include electrical connections, electric motors, transformers, wires and cables, uninterruptible power supplies, backup batteries and light fittings.

Troubleshooting with infrared thermometers

To find a hot spot in electrical systems, aim the infrared thermometer outside the area of interest. Squeeze the trigger and hold it down as you scan across the target with a slow up-and-down, side-to-side motion. Laser sighting shows you the exact area of measurement. Temperature variations appear instantly in the LCD readout. Once you have found the hot spot, you can zero in on the component causing the problem.

Finding faulty components

As the condition of an electrical component deteriorates, its resistance can increase and generate more heat. As the component temperature rises, the resistance increases further, generating even more heat. By utilising infrared thermography to inspect electrical systems and components under full load, the faulty components can be identified and classified by severity.

Check for overloaded circuits

As the load increases in a circuit, the temperature of its components will increase proportionately. An even load on each phase of a three-phase system, for example, should result in uniform temperature on all three phases. An anomaly is identified when the overall component and conductor temperature is too high, indicating an overload condition. An unbalanced condition can also be a problem, and is identified by the conductors not displaying a balanced or equal temperature.

Monitoring localised resistance

Resistance in an electrical circuit comes from components such as connections, wires, fuses, switches and breakers. Under standard operating conditions, each component will have a certain ‘normal’ resistance associated with it. It is when the resistance deviates from this norm that the component begins to heat up and must be identified and repaired.

As the component continues to deteriorate, the temperature will continue to increase until complete failure occurs. This type of fault can be identified because there is a hottest point, i.e., the heat being generated is greatest at the fault point with a tapering-off as one moves outward.

Detecting harmonic disturbances

Harmonics are currents or voltages that are multiples of the basic incoming frequency serving an electrical distribution system. The most damaging are high-frequency harmonics as these can cause overheating and even melting of components. Other equipment affected by harmonics are transformers, standby generators, motors, telecommunications equipment, electrical panels, and circuit breakers.

Identifying poor connections

Poor connections are one of the most frequently found problems in electrical systems. Routine inspection with an infrared thermometer lets you find these problems. The majority of thermal electrical problems involve improper torque specifications or improper installation at the junction points. A loosely torqued connector effectively reduces the surface area in which current can flow and consequently increases the contact resistance. Oxidation built up at the connection point can compound the problem by causing an additional rise in resistance. Most conductor, insulation and component problems can be traced to a poor connection somewhere.

Regular inspection pays dividends

An inspection with an infrared thermometer should be performed regularly in manufacturing plants. All cable runs, bus ducts, distribution panels, motor control centres, etc., should be checked for hot spots or heat imbalances. This can identify loose connections, overloads, unbalanced loads, and high neutral currents that need to be corrected.

Infrared thermometers provide an easy way to detect small changes in temperature – simply point, shoot and read. It is a non-contact, non-destructive and simple method of detecting impending electrical problems. Inspections can be at any time without shutting down the plant or facility. Since all common electrical problems announce themselves as an increase in temperature, they are easily detected in a minimal amount of time. Precise pinpointing of problems minimises the time required for predictive maintenance, and enables you to repair only what requires repairing, reducing maintenance time and unscheduled shutdowns and avoiding replacing good components.


Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Grid to backup power in zero seconds
Electrical Power & Protection
South Ocean Electric Wire has completed a solar installation that marks a global first: a seamless switch from grid to backup power in zero seconds.

Read more...
Three decarbonisation myths and how organisations can debunk them
Schneider Electric South Africa Electrical Power & Protection
A UN Climate Change Report revealed that the world is on track to miss its 2050 net zero targets, with temperatures expected to increase by over 2,4°C by 2100. To help shift positive intent to concrete action, Schneider Electric outlined three of the most common myths surrounding decarbonisation and how organisations can get started on their decarbonisation journey.

Read more...
Tackling the barriers of renewables and empowering the manufacturing sector
Electrical Power & Protection
Solar energy is surging in South Africa, but the energy is primarily self-consumed, meaning many manufacturing sites draw power directly and don’t gain more energy independence through comprehensive energy storage or hybrid energy solutions.

Read more...
Three-phase filters for electromagnetic interference
Vepac Electronics Electrical Power & Protection
Vepac Electronics has available three-phase filters that provide a solution to electromagnetic interference generated by equipment or from an AC source.

Read more...
The age of grid defection is upon us
Electrical Power & Protection
Solar and battery systems have got so cheap that many private individuals, farmers and companies are waking up to the fact that in many locations in South Africa it is now less expensive to be off the electrical grid than to be on it.

Read more...
Measure the electrical performance of your machinery
Vepac Electronics Electrical Power & Protection
The TELE eCap from Vepac Electronics allows you to use energy wisely and reduce operational expenses.

Read more...
Connectors for quick, easy and tool-free in-field termination
Electrical Power & Protection
KYOCERA AVX has released the new 9288-000 Series hermaphroditic wire-to-wire and wire-to-board connectors for lighting and industrial applications. These unique two-piece connectors facilitate WTW termination with two identical mating halves, which simplifies BOMs.

Read more...
Biomass is building up steam
Electrical Power & Protection
Pressure is mounting for local manufacturers to swap fossil fuels for biomass to reduce their carbon footprints and mitigate carbon taxes. Experienced steam and boiler operations and maintenance service provider, Associated Energy Services has spent the past 14 years reviewing solutions.

Read more...
Würth Elektronik expands its power module series
Electrical Power & Protection
Würth Elektronik has expanded its successful MagI³C-VDLM power module series with two new models that further enhance the performance of the existing portfolio of compact DC/DC power supply modules.

Read more...
The journey towards renewable energy in the Seychelles
Electrical Power & Protection
The Seychelles is committed to its ambitious goal of achieving net-zero carbon emissions by 2050. Recent technological advancements and strategic planning are steadily paving the way for a more sustainable future.

Read more...









While every effort has been made to ensure the accuracy of the information contained herein, the publisher and its agents cannot be held responsible for any errors contained, or any loss incurred as a result. Articles published do not necessarily reflect the views of the publishers. The editor reserves the right to alter or cut copy. Articles submitted are deemed to have been cleared for publication. Advertisements and company contact details are published as provided by the advertiser. Technews Publishing (Pty) Ltd cannot be held responsible for the accuracy or veracity of supplied material.




© Technews Publishing (Pty) Ltd | All Rights Reserved