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3 contactors are used: one for the main incoming service lines, one to make the star connection and one for the delta connection. Auxiliary to the contactors, a delay timer, adjustable from 500-1000 seconds, is used to shift from star to delta configuration.
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What is the Difference between auxiliary contactor and power contactors?
Power contactors are used primarily for more sophisticated equipment that need several different points of contact. Auxiliary contactors are primarily for single connections.
What is the advantage of a sequencer over a contactor?
Using contactors (or relays) to control electric heat means that all of the heat will be started at one time unless separate time delay relays are used. Contactors are magnetic and make noise. They snap in and may hum. Contactors are normally used on commercial systems where they may not be directly attached to the ductwork. This prevents the noise from traveling through the system - Sequencer are cheaper and quiet compared to contactors.
How does a contactor energise?
Contactors have movable contacts in them which are operated by the action of the solenoid that they are attached too. This solenoid is basically an electromagnet with a spring that resets the contacts to the open position when current is removed from the solenoid's coil/windings. When an electrical current is fed through the coil of the solenoid it creates a magnetic field; the force of the field is stronger than the opposing force of the restting spring thus the moving part of the solenoid which has the contacts attached to it, moves down completing the electrical circuit. Contactors are usually used in cases where the voltages and currents levels to be used are way beyond the capacity of a normal switch. A common example would be as a direct on line starter for a large electrical motor, which usually have large starting current of up to 5-8 times the run current of the motor. It is also important to note that voltage used to energize the contactors coil can be much smaller than the actual voltage be conveyed by the contacts which feed the electrical load.
Which material are used in tube light starter?
Bi Metallic
What is the difference between a Y - delta starter and a star - delta starter?
No difference. Y is used as a symbol to indicate the star connection.
What size of contactors used for 20hp star-delta starter?
The size of the contactors are dependant upon what the voltage the motor is operating on.
How many contactors using in star connection of motor?
two contecter <<>> There are three contactors used in a Star Delta configuration.
What is the Difference between auxiliary contactor and power contactors?
Power contactors are used primarily for more sophisticated equipment that need several different points of contact. Auxiliary contactors are primarily for single connections.
What is the advantage of a sequencer over a contactor?
Using contactors (or relays) to control electric heat means that all of the heat will be started at one time unless separate time delay relays are used. Contactors are magnetic and make noise. They snap in and may hum. Contactors are normally used on commercial systems where they may not be directly attached to the ductwork. This prevents the noise from traveling through the system - Sequencer are cheaper and quiet compared to contactors.
What are furnas contactors used for?
Furnas are one of the top names in heating, ventilation,air conditioning and refrigeration. They supply contactors and easy fit connections for an assortment of applications within the industry.
What devices are used to protect a three-phase motor and are placed on the bottom of contactors?
thermal overloads
What type of switch would be used to control a lighting load from one control point?
In this type of situation, where there is more than one lighting circuit, a lighting contactor would be used. These types of contactors can be obtained in four and five pole configurations. Make sure that the contactor is rated for lighting loads and not motor loads. A normal switch, single pole single throw, would be used to switch the contactors on and off. A single switch could then be used to control as many contactors as you need to operate the lighting circuits.If there is just one lighting circuit, the total circuit amperage must be known, then the switch would be sized to the amperage of the circuit.
What is the difference between contactor transformer?
Relays and Contactors are electromagnetic switches. The onlydifference is that relays are usually used for low voltageapplications while contactors are used for higher voltageapplication. Contactors usually have Overload protection.Some examples that I can give (at least in Manufacturing ofIndustrial Control panels):-Relays are use as electromagnetic switches to controlcertain parts of a circuit (low voltage application). Abetter example would be such as if you want your circuit tosound a horn when a certain abnormality is happening at acertain period of time, then depending how you set up yourcircuit, a specific relay will either open or close and youhorn will start making the sound.-Contactors can be used for example, to start motors or anumber of motors that require a higher voltage in order forthe motor or motors start working. In the example that Ijust gave, contactors work as starters.
Where the solenoid is used?
In the starter circuit, in many automatic transmissions, in EVAP circuits,
How does a contactor energise?
Contactors have movable contacts in them which are operated by the action of the solenoid that they are attached too. This solenoid is basically an electromagnet with a spring that resets the contacts to the open position when current is removed from the solenoid's coil/windings. When an electrical current is fed through the coil of the solenoid it creates a magnetic field; the force of the field is stronger than the opposing force of the restting spring thus the moving part of the solenoid which has the contacts attached to it, moves down completing the electrical circuit. Contactors are usually used in cases where the voltages and currents levels to be used are way beyond the capacity of a normal switch. A common example would be as a direct on line starter for a large electrical motor, which usually have large starting current of up to 5-8 times the run current of the motor. It is also important to note that voltage used to energize the contactors coil can be much smaller than the actual voltage be conveyed by the contacts which feed the electrical load.
How does a contactor?
Contactors have movable contacts in them which are operated by the action of the solenoid that they are attached too. This solenoid is basically an electromagnet with a spring that resets the contacts to the open position when current is removed from the solenoid's coil/windings. When an electrical current is fed through the coil of the solenoid it creates a magnetic field; the force of the field is stronger than the opposing force of the restting spring thus the moving part of the solenoid which has the contacts attached to it, moves down completing the electrical circuit. Contactors are usually used in cases where the voltages and currents levels to be used are way beyond the capacity of a normal switch. A common example would be as a direct on line starter for a large electrical motor, which usually have large starting current of up to 5-8 times the run current of the motor. It is also important to note that voltage used to energize the contactors coil can be much smaller than the actual voltage be conveyed by the contacts which feed the electrical load.
What is electrical maintenance?
Electrical maintenance is used for maintenance of electrical equipment. Electrical Preventive Maintenance is been used for replacement of Low voltage distribution products such as ACB's & MCCB's Contactors and Relays.
