Top Document: Electrical Wiring FAQ (Part 1 of 2) Previous Document: "grounding" versus "grounded" versus "neutral". Next Document: Breakers? Can't I use fuses? See reader questions & answers on this topic! - Help others by sharing your knowledge Fuses and circuit breakers are designed to interrupt the power to a circuit when the current flow exceeds safe levels. For example, if your toaster shorts out, a fuse or breaker should "trip", protecting the wiring in the walls from melting. As such, fuses and breakers are primarily intended to protect the wiring -- UL or CSA approval supposedly indicates that the equipment itself won't cause a fire. Fuses contain a narrow strip of metal which is designed to melt (safely) when the current exceeds the rated value, thereby interrupting the power to the circuit. Fuses trip relatively fast. Which can sometimes be a problem with motors which have large startup current surges. For motor circuits, you can use a "time-delay" fuse (one brand is "fusetron") which will avoid tripping on momentary overloads. A fusetron looks like a spring-loaded fuse. A fuse can only trip once, then it must be replaced. Breakers are fairly complicated mechanical devices. They usually consist of one spring loaded contact which is latched into position against another contact. When the current flow through the device exceeds the rated value, a bimetallic strip heats up and bends. By bending it "trips" the latch, and the spring pulls the contacts apart. Circuit breakers behave similarly to fusetrons - that is, they tend to take longer to trip at moderate overloads than ordinary fuses. With high overloads, they trip quickly. Breakers can be reset a finite number of times - each time they trip, or are thrown when the circuit is in use, some arcing takes place, which damages the contacts. Thus, breakers should not be used in place of switches unless they are specially listed for the purpose. Neither fuses nor breakers "limit" the current per se. A dead short on a circuit can cause hundreds or sometimes even thousands of amperes to flow for a short period of time, which can often cause severe damage. User Contributions:Comment about this article, ask questions, or add new information about this topic:Top Document: Electrical Wiring FAQ (Part 1 of 2) Previous Document: "grounding" versus "grounded" versus "neutral". Next Document: Breakers? Can't I use fuses? Part1 - Part2 - Single Page [ Usenet FAQs | Web FAQs | Documents | RFC Index ] Send corrections/additions to the FAQ Maintainer: clewis@ferret.ocunix.on.ca (Chris Lewis)
Last Update March 27 2014 @ 02:11 PM
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I bought a new receptacle and installed the same. I still have no power I suspect there could be a bigger problem,this is aluminum wiring.
I've killed the breaker and call an electrician but am curious as to what happened.P.s. there is a dimmer switch on the same circuit.
I have multiple switches to lights. Ran 12/2 and 14/3 into switch box and inspector wrote correction needed.
What should I have done instead?
thank you
dennis
Ex: 15 amp-14awg. 12awg-20amp only rule for thumb other factors such as continuous load,heating and others if you do not know the safe NEC rules then please call a qualified journeyman Electrician better be safe