Overheating is a phenomenon of rising of temperature in an electric circuit (or portion of a circuit). Overheating causes potential damage to the circuit components, and can cause fire, explosion, or injury. Damage caused by overheating is commonly irreversible; i.e. the only way to repair is to replace some components.
Video Overheating (electricity)
Causes
On overheating, the temperature of the part rises above the operating temperature. Overheating can take place
- if heat is produced in more than expected amount (such as in cases of short-circuits, or applying more voltage than rated), or
- if heat dissipation is poor, so that normally produced waste heat does not drain away properly.
Overheating may be caused from any accidental fault of the circuit (such as short-circuit or spark-gap), or may be caused from a wrong design or manufacture (such as the lack of a proper heat dissipation system).
Due to accumulation of heat, the system reaches to an equilibrium of heat accumulation vs. dissipation, at a much higher temperature than expected.
Maps Overheating (electricity)
Preventive measures
Use of circuit breaker or fuse
Circuit-breakers placed at different portions of circuit (in series to the path of current it will affect). If more current than expected goes through the circuit-breaker, the circuit breaker "opens" the circuit and stops all current. A fuse is a kind of widely used circuit breaker, that involves direct effect of Joule-overheating. A fuse is always placed in series with the path of current it will affect. Depending upon work, inside a fuse, there is a narrow (often a hairline) wire of definite-material, in the fuse. When more-than expected current flows through the fuse; the fuse-wire overheats (melts) and "opens" the circuit. In some gadgets, more than one
Use of heat-dissipating systems
Many ventilator holes or slits kept on the box of equipments. Heat sinks (heat-radiating metallic objects) attached with some-portions of the circuit that produce more heat/ more vulnerable to heat. often, fans are required. Some high-voltage instruments kept immersed in oil. In some cases, to remove unwanted heat, some cooling-system like air-condition or refrigerating-heat-pumps may be required.
Control within circuit-design
Sometimes special circuits built for purpose of sensing the temperature or voltage status, and thereafter controlling these variables. In these circuits, Thermistors (Temperature dependent resistors), VDR (voltage-dependent resistors), thermostat (that switches off the circuit at higher-temperature), Sensors (such as infrared-thermometers), etc. used to modify the current upon different conditions like circuit-temperature and input voltage.
Proper manufacture
For a certain definite purpose in a definite electrical equipment or a portion of it, definite type and size of materials (for boards,wires, insulators) with proper rating for voltage, current and temperature,are used. The circuit-resistance never kept too-low. Sometimes some parts placed inside the board and box, maintaining a proper distance from each-other, to avoid heat-damage and short-circuit-damage. To prevent short-circuit, on the wire-joints, appropriate type of electrical connectors and mechanical fasteners used.
See also
References
Sources
- ^ http://www.ufba.org.nz/images/documents/hazardsandsafeguards.pdf
- ^ "Classification of Electrical Overheating Modes - Electro-Mechanical Recertifiers, Inc". Retrieved 27 August 2016.
- ^ ElectroTechnik. "What are the reasons for transformer overheating?". Retrieved 27 August 2016.
- ^ "The Basics of Electrical Overheating". Retrieved 27 August 2016.
- ^ http://www.testequipmentdepot.com/application-notes/pdf/power-quality/case-study-the-overheating-transformer_an.pdf
- ^ http://protectowire.com/documents/ds-8899.pdf
- ^ http://www.mirusinternational.com/downloads/hmt_faq10.pdf
- ^ http://www.learnabout-electronics.org/Downloads/ac_theory_module11.pdf
- ^ "Power Transformers". Retrieved 27 August 2016.
- ^ http://sound.whsites.net/xfmr.htm
- ^ http://sound.whsites.net/xfmr-6.jpg
- ^ "Top 14 Reasons Electrical Service Installations Get Red Tagged". Retrieved 27 August 2016.
- ^ http://ecmweb.com/site-files/ecmweb.com/files/uploads/2016/03/Electrical-Service-Meltdown-6.jpg
Source of article : Wikipedia
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