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Can alternating current be switched using normally open switch relays?
Wiki User
∙ 12y ago
Yes. In fact, induction motor 'starters' work using normally-open relays, controlled by low-current control circuits -although we call these heavy-duty relays 'contactors'.
Wiki User
∙ 12y ago
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Which instrument transformer mostly used in relays?
Both Current and Potential Transformers are used for relays according to the working of relay.
How can the path of current be controlled in different circuits?
Transistors and/or relays.
What is under current relays?
A device that disconnects a circuit when ever it detects the electric current is lower than the rated current.
Which starting system component uses a small amount of current to control a large amount of current?
I think its a starter solenoid or a relay. I know relays take high voltage current to power low voltage circuits. Hope that helps..
What is a time delay relay function used for?
A time delay relay is used in applications that have a need to be automatically switched on and off. A few applications that require time delay relays are strobe lights, stoplights, and Christmas tree lights.
What does AC stands for on relays and fuses?
Alternating Current as opposed to DC Direct Current
What are current relays?
Current relays are the relay which sens the current passing in particular circuit and operates when this current exceed its set value.
Can we drive relays by current transformers?
Yes, certain types of relays can be activated by current transformers.
How does a transformer protect an appliance?
Normally current transformers are used for two things . For measuring and protection. Whenever the CT is a protection CT it will be connected with the protection relays and there will be setting in the relays based on our requirement. when the current pass through the relays are more than the setting range then relay will send the tripping signal to the breaker available in the system to isolate the fault section. Finally the CT is not protecting the system. it will transfer the high primary current from the system to relay as small secondary current.
Why relays are used in car?
Relays are used to control high current using low current. They help eliminate a lot of unnecessary wiring.
What does the relay do for the car?
There are three types of relay. Normally open relays mean the electric current can't pass until something causes the relay to close and complete the circuit. Example: when you start your car you are closinga relay when you turn the key and the circuit to the starter is allowing electricity to the starter. Normally close relays mean the circuit always has electricity unless you do something to stop it. Last but not least is a switching relay where the power is switched from one circuit to the next. Example: headlights bright to dim also dims or brightens the dash lights.
Why current transformers are required in protective relaying scheme?
Current transformers (CTs) are used to monitor the current (or lack of) in high-voltage systems, and their secondary outputs controls the behaviour of protection-system relays. The CTs (1) reduce the current to values that match the current ratings of the protective relays, and (2) electrically-isolate the relays from the high-voltage system.
What is the purpose of individual units or component and how do they interact?
18. Component Description and applicationRelay Relays are a special type of switch which is turned on and off by an electromagnet. When a current flows through the coil an electro-magnetic field is set up. The field attracts an iron armature, whose other end pushes the contacts together, completing the circuit. When the current is switched off, the contacts open again, switching the circuit off.A useful property of relays is that the circuit powering the coil is completely separate from the circuit switched on by the relay. For this reason relays are often used where a safe low-voltage circuit is being used to control a high-voltage circuit.Contactor A contactor is an electrically controlled switch used for switching a power circuit. A contactor is activated by a control input which is a lower voltage / current than that which the contactor is switching. Unlike general-purpose relays, contactors are designed to be directly connected to high-current load devices, not other control devicesCapacitor Capacitors store and discharge electrical current. They're made from 2 parallel metal plates separated by an insulator (dielectric) applications include;Smoothing rectified alternating current voltages into steady direct current voltagesBlocking direct current signals whilst allowing alternating signals to passFiltering out unwanted portions of a fluctuating signalTiming applicationsStoring charge to keep a transistor turned on or offSensor A sensor is a type of transducer. There is a massive range of sensors Direct-indicating sensors, for example, a mercury thermometer, are human-readable. Other sensors, such as thermocouples, only produce an output voltage or other electrical output which must be interpreted by another device (such as a computer).Resistor Resistors resist or 'slow down' the current in a circuit by acting against the flow of electrons.hope this helps your NVQ work
Which instrument transformer mostly used in relays?
Both Current and Potential Transformers are used for relays according to the working of relay.
How can the path of current be controlled in different circuits?
Transistors and/or relays.
What is under current relays?
A device that disconnects a circuit when ever it detects the electric current is lower than the rated current.
About bus bar protection ques and ans?
Protection of busbars is mainly done using differential relays. These relays sense current flowing into the bus and current flowing out of the bus. If current in != current flowing out, the relay assumes there is a fault on the bus and trips breakers to isolate the bus.
