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An electrical switching device that in it's normal rest state does not conduct an electrical current. To become conductive an external force must be applied to change, (switch), it's physical state from open to closed.
Wiki User
∙ 13y ago
Wiki User
∙ 13y agoA normally open switch is a type of switch that the connection is not made until you push a button; when the button is released, the connection is broken. A normally closed switch is when a connection is made whenever the button is not pushed, and then the connection is broken when the button is pushed. Open=not connected; Closed = connected.
Wiki User
∙ 14y agoNormally open contact of a contactor or relay become close when the contactor or relay energized its roll like a door which open and close with the operating of its coil energized
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What is Contact block 1N.O. 1N.C. 1N.O. scaled?
It is a contact block with three poles. Pole one is normally open, pole two is normally closed and pole three is normally open. These reading are taken in a de-energized condition. When energized the contacts will change status to closed, open and closed.
How can you make a light bulb go off when a door is opened?
Use a normally closed (NC) contact switch rather than a normally open (NO) momentary contact switch.
What is close contact relay?
A relay is an electrical switch. It consists of a electromagnetic coil and a set of mechanical contacts. Depending on the relay their could be multiple sets of mechanical contacts. The close contact lets current flow through the mechanical contacts when the relay is not turned on. When the relay is turned on current flow is stopped. This is called a normally closed contact or NC The open contact works the opposite of the closed and is referred to as a normally open contact or NO
What is a nc contact?
An N.C. contact is 'Normally closed'. This applies to relays (electronic switches). You can use either a normally closedcontact or a normally open contact to do what you need, provided the relay has both and depending on your situation. Here's a recent example of mine: A building's fire alarm is wired to the HVAC system to shut down ventilation in case of a fire. In this case we want the HVAC to have power normally but remove power (with the relay) during a fire alarm. We would connect the HVAC power to the relay's N.C. (normally closed) contacts, because they are exactly that: normally closed. This would allow the HVAC to function. When power is applied to the relay, it would switch contacts, disconnecting power to the HVAC. An important note is that contacts and other electrical connections that can change condition (such as a relay) are described in a de-energizedstate. Thus, the N.C. contacts are normally closed, while the power to the relay is off. Likewise, a N.O. contact is open with relay de-energized but will close upon supplying power to the relay.
Is a npn phototransistor normally open or normally closed?
It depends on the phototransistor's design. Most are normally open until you shine light on them.
What is Contact block 1N.O. 1N.C. 1N.O. scaled?
It is a contact block with three poles. Pole one is normally open, pole two is normally closed and pole three is normally open. These reading are taken in a de-energized condition. When energized the contacts will change status to closed, open and closed.
How does a normally closed contact work?
De-energize it and note the position of the contacts.
How does an off delay timer work?
when off delay timer gets control signal, its NO(NORMALLY OPEN) contact become NC(NORMALLY CLOSED) for preset duration, and then become NO.
What does nc and no mean in electrical terms?
nc: Normally Closed (contact is closed when power is not applied) no: Normally Open (contact is open when power is not applied) Applies to a relay ex...: when power is applied to a relay the no(Normally Open contact will close and allow current to flow between two terminals on relay).
How can you make a light bulb go off when a door is opened?
Use a normally closed (NC) contact switch rather than a normally open (NO) momentary contact switch.
What is a virtual contact center?
A virtual contact center has no physical location. The representatives normally work from home.
A device that opens and closes a set of contacts when its coil is energize?
The device is a relay. A relay may have several sets of contacts, or sets of open and closed contacts that "change state" as the coil is energized.Changing state means that the normally open contact will close and the normally closed contact will open when the coil is energized.
How do you open up a zoo in your own town?
You can contact the leader of your state otherwise you would have to get alot of paper work and $ to open your own zoo You can contact the leader of your state otherwise you would have to get alot of paper work and $ to open your own zoo
What is close contact relay?
A relay is an electrical switch. It consists of a electromagnetic coil and a set of mechanical contacts. Depending on the relay their could be multiple sets of mechanical contacts. The close contact lets current flow through the mechanical contacts when the relay is not turned on. When the relay is turned on current flow is stopped. This is called a normally closed contact or NC The open contact works the opposite of the closed and is referred to as a normally open contact or NO
What is a normally open contact?
A normally open contact is similar to a spring loaded switch, found in push buttons, and relays. For a push button, when you push the button, the button head has a piece of metal that makes contact between two external screws, where the wires are attached. For a relay, the concept is the same, but instead of pushing the button yourself, the relay would be turned on and off by an external electronic device.
What is a nc contact?
An N.C. contact is 'Normally closed'. This applies to relays (electronic switches). You can use either a normally closedcontact or a normally open contact to do what you need, provided the relay has both and depending on your situation. Here's a recent example of mine: A building's fire alarm is wired to the HVAC system to shut down ventilation in case of a fire. In this case we want the HVAC to have power normally but remove power (with the relay) during a fire alarm. We would connect the HVAC power to the relay's N.C. (normally closed) contacts, because they are exactly that: normally closed. This would allow the HVAC to function. When power is applied to the relay, it would switch contacts, disconnecting power to the HVAC. An important note is that contacts and other electrical connections that can change condition (such as a relay) are described in a de-energizedstate. Thus, the N.C. contacts are normally closed, while the power to the relay is off. Likewise, a N.O. contact is open with relay de-energized but will close upon supplying power to the relay.
How does an electric relay work?
Relay contactsThe contacts could be in a normally open or they could be in a normally closed position depending on the type of relay it is. Most relays have their contacts in a C form configuration. This means that there is a common terminal to which the hot wire is connected and two sets of contacts one above and one below the common movable contact. In the de-energized state, between the common movable contact and the contact above will be in a N.C. (normally closed) position. This leaves the contact below and the common movable contact in a N.O. (normally open) position. The contact status is held in this position by a small spring. When the relay coil is energized, the state of these contacts reverse. The relay coils magnetism pulls on the coil armature, to which the common contact is attached, and over comes the pressure of the spring tension. The N.C contact becomes N.O and the N.O. contact becomes N.C. When reading an electrical schematic all relays contacts are drawn in the de-energized position.
