Search results
Results from the WOW.Com Content Network
A high-resistance connection (HRC) is a hazard that results from loose or poor connections in traditional electrical accessories and switchgear which can cause heat to develop, capable of starting a fire. [1] Glowing connections occur when relatively high current exists in a relatively large resistance object. Heat comes from power dissipation ...
An arc flash is more likely to form in a switch that is closed slowly, by allowing time for an arc to form between the contacts, so it is usually more desirable to "throw" switches with a fast motion, quickly and firmly making good contact. High-current switches often have a system of springs and levers or even pneumatic assists to assist with ...
Glitched and garbled display on a workstation laptop with a defective graphics card that underwent extensive overheating from use in a hot environment. The second image shows the same laptop failing to operate properly due to the aforementioned graphics card defect, crashing the operating system and displaying a blue screen of death (albeit ...
An overcurrent caused by a fault in the transformer or customer circuit will cause the fuse to melt and the switch mechanism to visibly open, disconnecting the transformer from the line. The device can also be opened manually by utility linemen standing on the ground and using a long insulating stick called a "hot stick".
Contact resistance can cause significant voltage drops and heating in circuits with high current. Because contact resistance adds to the intrinsic resistance of the conductors, it can cause significant measurement errors when exact resistance values are needed. Contact resistance may vary with temperature.
When the contacts touch, the switch is closed; when the contacts are separated, the switch is open. The gap must be an insulating medium, such as air, vacuum, oil, SF 6. Contacts may be operated by humans in push-buttons and switches, by mechanical pressure in sensors or machine cams, and electromechanically in relays.
Discover the latest breaking news in the U.S. and around the world — politics, weather, entertainment, lifestyle, finance, sports and much more.
A residual-current device (RCD), residual-current circuit breaker (RCCB) or ground fault circuit interrupter (GFCI) [a] is an electrical safety device that interrupts an electrical circuit when the current passing through a conductor is not equal and opposite in both directions, therefore indicating leakage current to ground or current flowing to another powered conductor.