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What will happen if you close isolator after closing circuit breaker while closing the circuit?
Wiki User
∙ 11y ago
If the isolator switch is not load break rated then there could be a phenomena called a flash over, or arc flash. This is a dangerous event. A current will continue flowing through the air gap that is created when opening a switch until the air gap becomes wide enough and the potential on the wire is not high enough to keep the current flowing.
Breakers are load break rated in their design. They have magnetic arc chutes located close to the opening contacts that help extinguish the arc when the breaker contacts are opened. So the sequence to use is, open the breaker first and then open the isolation switch. Always remember to lock the isolation switch in the off position when working on the equipment down stream from it.
Wiki User
∙ 12y ago
Wiki User
∙ 11y agoMost isolation switches are not rated as current interrupting switches. Closing the switch should not be a problem. It is opening one of these types of switches under load where the problem arises. The switch has no arc chutes to extinguish the arc when the switch's blades are opened. There will be a long electric arc drawn from the stationary blade to the movable blade as the current wants to keep flowing.
Proper procedure is to open the circuit supply breaker, lock it out, and then open the isolation switch. When the work is complete on the equipment that is being worked on, close the isolation switch and then unlock the supply circuit breaker and turn it on.
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Is it possible that a circuit breaker can explode?
The definition of the word explosion is, a rapid expansion of gases. It may occur from physical or mechanical change. As there in no gases involved in a common circuit breaker the answer has to be a definite no. If a circuit breaker short circuits internally across the line the only thing that will happen is the safety protection up stream from the breaker will trip and take the faulted breaker off line.
Difference between load break switch and isolator?
An isolator(disconnecting switch)operates under no load conditionand used for disconnecting the CB from the live part of the maintenance.Isolators are used in addition to the CB to make and break the circuit under normal and short circuit condition.A circuit breaker(CB) is an equipment which can open or close a circuit under normal as well as fault conditions and it can be operated manually under normal conditions and automatically under fault conditions.For the latter operation a relay is used with a CB.
Why is it important that homes have circuit breakers?
Fuses and circuit breakers are meant to protect your home's wiring from the heat generated from fault-currents and over-currents. Over-currents happen when you exceed the amperage the fuse or breaker is rated for over a period of time (IE: drawing 20 amps on a 15 amp circuit breaker). When this occurs a fuse or circuit breaker will open the circuit so the wiring in your home will not be damaged. Over-currents happen when electricity finds a path, other than the one intended, to ground. When this happens there is very little resistance to slow the flow of electricity and the amperage through the circuit can exceed the fuse or circuit breakers rated capacity by several hundred times . These type of faults cause the fuse or circuit breaker to open the circuit very quickly.
What will happen if a phase and neutral test by a mutimeter shows continuity?
If the test shows that there is a continuity between the phase leg and the neutral with no load connected, then that circuit should not be energized. If the circuit was energized then the fuse or breaker protecting that leg will trip the circuit open.
What will happen to the total current if you keep adding bulbs in parallel to the circuit?
Adding more lamps in parallel (across) a line will cause total current to climb. It will keep climbing (increasing) until a load protection device (circuit breaker or fuse) breaks the circuit or until something fails because of excessive current.
What happens when the circuit is complete and the switches are closed?
*Look at the simple circuit illustrated in Figure A-2. What will happen when only switch S1 is closed? Correct Answer= "Nothing will happen-the light bulb won't light up." <<>> If there is a load in the circuit the load will operate. If there is no load in the circuit and it is complete then a short circuit will occur and something in the circuit will burn open. If the circuit is complete and there is a fuse or breaker in the circuit, then the fuse or breaker will open the circuit.
What is the anti-pumping scheme of Circuit breaker?
in order to stop the repetitive closure of the circuit breakers, anti pumping relay scheme is used. i.e suppose that an operator gives a close command to the breaker(via some switch), now the fault occurs, the breaker would tend to clear the fault and open the contacts.But since the operator has given the close command, it would cause closing of breaker again and again.. so anti pumping relay is used to ensure that this does not happen!
Is it possible that a circuit breaker can explode?
The definition of the word explosion is, a rapid expansion of gases. It may occur from physical or mechanical change. As there in no gases involved in a common circuit breaker the answer has to be a definite no. If a circuit breaker short circuits internally across the line the only thing that will happen is the safety protection up stream from the breaker will trip and take the faulted breaker off line.
When a switch in an electrical circuit is turned off what will happen?
Closing a switch in an electrical circuit will complete the circuit. The supply voltage will then be applied to that circuit, and current will flow through that circuit.
What would happen if a 240V breaker was on and someone attempted to turn on the clothes dryer?
Don't understand this question. If the breaker is on, then the dryer would function normally, if the breaker your are referring to is the one for the dryer. If the breaker is off then no function. A dryer runs on 220.
What do you think would happen if you put a 3A fuse in a plug used for kettle?
I know what would happen. The three amp fuse would blow. Any device that is plugged into a receptacle with out having sufficient resistance to limit the current flow will dead short the circuit and cause the breaker that feeds the circuit to trip. In this case the fuse being of a lower rating that the feed breaker the fuse will blow without tripping the receptacle's feed breaker.
Difference between load break switch and isolator?
An isolator(disconnecting switch)operates under no load conditionand used for disconnecting the CB from the live part of the maintenance.Isolators are used in addition to the CB to make and break the circuit under normal and short circuit condition.A circuit breaker(CB) is an equipment which can open or close a circuit under normal as well as fault conditions and it can be operated manually under normal conditions and automatically under fault conditions.For the latter operation a relay is used with a CB.
Why is it important that homes have circuit breakers?
Fuses and circuit breakers are meant to protect your home's wiring from the heat generated from fault-currents and over-currents. Over-currents happen when you exceed the amperage the fuse or breaker is rated for over a period of time (IE: drawing 20 amps on a 15 amp circuit breaker). When this occurs a fuse or circuit breaker will open the circuit so the wiring in your home will not be damaged. Over-currents happen when electricity finds a path, other than the one intended, to ground. When this happens there is very little resistance to slow the flow of electricity and the amperage through the circuit can exceed the fuse or circuit breakers rated capacity by several hundred times . These type of faults cause the fuse or circuit breaker to open the circuit very quickly.
What will happen if a phase and neutral test by a mutimeter shows continuity?
If the test shows that there is a continuity between the phase leg and the neutral with no load connected, then that circuit should not be energized. If the circuit was energized then the fuse or breaker protecting that leg will trip the circuit open.
What happen if the window is not going up or down?
One window, probably the switch or the electric window motor. All windows, probably the fuse or circuit breaker.
Which circuit faults will not result in overheating the circuit?
An open circuit won't cause any overheating because no current is flowing. Other faults like ground fault or a breaker tripping should happen fast enough not to cause any overheating either.
Why fuse wire is placed in series with the device?
circuit breaker and fuses used in series to break the circuit in overcurrent situation to block current to flow through circuit.
