Electricity and Control November 2020

PLANT MAINTENANCE, TEST + MEASUREMENT : PRODUCTS + SERVICES

IR thermometers in electrical maintenance

Because electrical currents generate heat – too high a temperature indicates prob- lems – checking temperature is an effective

Infrared thermometers can be used to measure temper- ature accurately from a distance. The IR thermometer should be aimed outside the area of interest and the user simply needs to squeeze the trigger and hold it down, scanning slowly across the target. Laser sighting shows the exact area of measurement and temperature varia- tions appear instantly in the LCD readout. Once the hot spot has been located, the user can focus on the compo- nent 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’s temperature rises, the resistance increases further, generating more heat. Using infrared thermography to inspect electrical systems and components under full load, faulty components can be identified and classified by severity. Because heat loss is proportional to the current, unbalanced or overload conditions can also be identified with infrared thermometry. Checking for overloaded circuits As the load increases in a circuit, the temperature of the entire circuit and components on the circuit will increase. 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 indicated by the conductors not displaying a balanced or equal temperature. Power Technologies (MPT), a leading provider of secure and reliable backup power solutions in Africa. MPT’s remote monitoring solution meets both these requirements and adds the safety and convenience of keeping human intervention to a minimum. The Master Power Universal Controller is at the heart of the solution and incorporates HVAC monitoring in its portfolio of critical applications. HVAC monitoring The Universal Controller reads all critical data from HVAC units using Fieldbus communications and digital alarm signals. Status readings, alerts, alarms and operational data are recorded for analyses of system efficiencies, equipment failures, maintenance requirements and breakdown situations. Based on real-time hardware and software monitoring, the Universal Controller takes intelligent, automatic action to address issues that could otherwise cripple essential functions, such as components at risk of failing.

Heating, ventilation and air conditioning (HVAC) systems are critical in various economic sectors: from maintaining the cold chain in the production of foods and beverages, to ensuring the correct operation of servers in data centres. While the continuous functioning of HVAC systems is critical in such applications, they are notoriously power hungry. They also require robust and reliable backup pow- er solutions to ensure they stay operational in the event of power interruptions. method of condition monitoring to guard against component failure in electrical systems. Non-con- tact, 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 Check for loose connections caused by repeated on/off operation. Loose connections mean higher resistance, which causes overheating. Overheating can also result from corrosion, the presence of dirt or carbon deposits. - Electric motors Check for phase imbalance on three-phase motors, and check windings and bearings for overheating. - Transformers Check for hot spots that indicate winding problems. - Wires and cables Check for excessive heat as a result of cracks, corrosion or deterioration. - Uninterruptible power supplies Check for hot battery terminals suggesting loose connections or corrosion. Detect hot or cold spots in output filters. - Backup batteries Check for poorly attached connections in a battery string, which can cause posts to heat up and possibly burn. - Lighting fittings Check for loose connections and aging components. Remote monitoring of HVAC secures the cold chain

IR thermometers are especially useful in detecting faults in electrical equipment and systems.

“It makes sense to invest in technology that optimises HVAC functioning and performance, and ensures

backup power,” says Rory Reid, Sales and Marketing Director for Master

MPT’s Universal Controller provides for remote monitoring of HVAC systems in critical applications.

28 Electricity + Control NOVEMBER 2020