A closed breaker has some voltage going through - how is that possible?


Circuit Breaker- Need and Definition

Basically electricity coming to our house or to any other places from the power distribution grids forms a large circuit with the lines connecting to the power plant forming one end called the hot wire and the lines connecting to ground forming other end. Electrical charge flows between these two lines and potential is developed between them. The connection of loads(appliances) offering resistance to this flow of charge completes the full circuit and the whole electric system inside the house works smoothly as long as the appliances have sufficient resistant and do not cause any over current . Short circuiting or too much charge flowing through the circuit or sudden connection of the hot end wire to the ground wire would heat up the wires, causing fire. To prevent such situations a circuit protection is used which simply cuts off the remaining circuit in such conditions.

Generally there are two ways of solving this above...

0 0

The primary function of an

electrical circuit breaker

is to provide opening and closing of the


carrying contacts. Although it is seems to be very simple. But we should remember, that, one

circuit breaker

remains at its closed position for maximum period of its life span. Very occasionally it is required to operate a circuit breaker for opening and closing its contacts. Hence,

circuit breaker operation

must be very reliable without any delay or sluggishness. For achieving this reliability the

circuit breaker operating mechanism

becomes more complex than it was first thought.

Opening and closing distance stroke between contacts and velocity of moving contacts during operation, are the most important parameters to be considered during designing circuit breaker. Contact gap, traveling distance of moving contacts and their velocity are determined by types of arc quenching medium, current and voltage rating of a circuit breaker.A typical...

0 0

different between grounding & earthing?

21 Answers L&T,

In all electric motors, fans are provided to dissipate heat. How it dissipate the heat? By absorbing atmospheric air or by exhausting the heated air generated while running?

2 Answers Ford,

how does commutator convert a.c to d.c?

0 Answers RBC, NRSC National Remote Sensing Centre,

If genrator not build up voltage , How u can Manually Excite ?

2 Answers

Why we are getting low voltage in star connection?

2 Answers

What will happen if primary of transformer is fed with Square wave instead of sinsoidal wave ?Will it operate or Not?

3 Answers Areva,


5 Answers

What is the importance of setting TSM & PSM?

2 Answers

what is the voltage between earth & neutral in 3 phase electrical connection.

0 Answers SIPL,...

0 0
All Rights Reserved

Reproduction of this document in whole or in part is permitted if both of the following conditions are satisfied:

1. This notice is included in its entirety at the beginning.
2. There is no charge except to cover the costs of copying.


Careless troubleshooting of a microwave oven can result in death or worse. Experienced technicians have met their maker as a result of a momentary lapse of judgement while testing an oven with the cover removed. Microwave ovens are without a doubt, the most deadly type of consumer electronic equipment in wide spread use.

The power supplies for even the smallest microwave ovens operate at extremely lethal voltage and current levels. Do not attempt to troubleshoot, repair, or modify such equipment without understanding and following ALL of the relevant safety guidelines for high voltage and/or line connected electrical and electronic systems.

We will not be...

0 0

Synchronous Generator Voltage

AC generator voltage,excitation current, voltage drop and power flow

I am a non-electrical engineer and have hard time understanding some electrical aspects of the generators.

Background: Steam driven turbine, AC, three phase generator.

Excitation current determines the strength of the magnetic field of the coil (along with speed of the rotor). Got it. This magnetic field then induces voltage at the generator terminals. If the generator is not connected to the load (or anything), there is no power flow, but voltage is established with this magnetic field. The voltage will be strictly a function of rotor speed and excitation current (and voltage). Got it.

Connected to the load: When connected to the load, the generator voltage drops with the increasing load. Voltage regulator however will increase (change) excitation current/voltage to maintain constant generator voltage.

Connected to the grid: When connected to...

0 0

In normal automotive use the current in the primary is interrupted at the appropriate time to generate a spark at the spark plug to ignite the fuel-air mixture in a car’s engine. In old cars the current is interrupted by a mechanical switch called the points, which are opened and closed by a cam on a shaft that rotates when the engine is running. In newer implementations a sensor sends a signal to an electronic module to cause a semiconductor switch in the module to open and generate the spark at the proper time.

All that is needed to use the coil to generate arcs for experimentation and display is a circuit that turns a switch on and off to interrupt the primary current of the ignition coil. Concerns such as adjustments to the timing to ignite the fuel in cylinder at the proper time do not apply for a display application.

The diagram below shows the basic blocks of a system used to generate acrs using an ignition coil. The general drive circuit consists of a pulse...

0 0
Common Thermostat Problems...more advanced to follow, but start with the basics first.Work with the power off whenever possible.When a furnace does not work it may be caused by problems with the furnace or the thermostat.

Before troubleshooting your thermostat, check to see if all filters are clean and all hoses to and from the units themselves are free of wear.
If these are not causing problems, then it is time to look at specific thermostat issues and possible solutions.

Your thermostat could have aging wiring that is faulty or the transformer may require replacing.

A thermostat may need cleaning to eliminate erratic operation.

Accumulated dust is a common culprit.

First, you should have a small paintbrush, a screwdriver, and a voltmeter.

anticipator is a small metal tab positioned in front of an arcing printed scale. Give it a light push in both directions. This easy step may solve the

Give the thermostat's...

0 0
0 0