Application of CEM infrared thermometer in electrical aspects
Interphase measurement
High-voltage, three-phase power circuits are common in industrial power systems. Phase-to-phase measurements are very important for induction motors, large computers, and other equipment that require balancing power between phases. If power balance is not maintained due to overloads or grounding in the circuit, damage and production outages can occur. Using a non-contact thermometer, you can check the cables and connectors to determine if the phase-to-phase temperatures are equal. A temperature difference of more than 5°C (9°F) may indicate a problem.
transformer
The maximum allowable operating temperature is usually listed on the transformer. The windings of air-cooled transformers can be measured directly using an infrared thermometer to determine the total temperature. Any hot spots indicate a defective winding.
Wires and cables
Wires and cables can be monitored using non-contact thermometers to detect heat caused by cracks, corrosion or deterioration. When comparing two cables, the warmer cable carries the greater current.
ups
DC battery connectors are prone to loosening and corroding, and thus generating excess heat. Locally high temperature connections in the UPS output filter can be identified using an infrared thermometer. A cold spot may indicate that the DC filter output is disconnected.
Backup battery
Low voltage batteries should be checked using a non-contact thermometer to ensure proper connections. In the battery pack, the connected battery spring connector may increase the temperature and eventually burn out the terminals.
ballast
Aged electrical components can cause lighting fixtures to overheat. An infrared thermometer can be used to detect overheating before the ballast starts to smoke.
Electrical facilities
In the factory, infrared readings can be used to quickly and cost-effectively identify hot spots on connectors, cable lugs, transformers and other equipment. Routine temperature checks can help prevent costly equipment failures and downtime. On-site inspections of power facilities mean regular temperature measurements of transformers, cables and other components that are at high altitudes and difficult to access. Several models of Fluke infrared thermometers feature unrivaled 60:1 optical resolution, making it easy to measure many targets. If you work in a petrochemical plant, refinery, or other location where flammable gases may be present, you should consider a hazardous location-ready infrared thermometer, such as the Fluke 68IS or Fluke 574NI.
Interpret results
After taking a temperature reading, how do you know when there is an actual problem? Obtaining this answer requires combining the service or maintenance technician's own experience with the ratings provided by the manufacturer of the equipment and electrical components being monitored. Manufacturers of electrical equipment usually list the maximum allowable temperature on the nameplate.
