The relationship between the contact spacing and the voltage of the contactor

This is closely related to the environment in which the contacts are located, for example, 10kV contacts only have a pitch of 3-4 mm in vacuum, 120 mm pitch in insulating oil, and more than 200 mm pitch in air, for example, the pitch of a 10kV disconnector is about 300 mm.

Contactors are used to turn on and off AC and DC main circuits and high-capacity control circuits over long distances and frequently. Its main control object is the electric motor, and it can also be used to control electric loads such as electric heating equipment, electric lighting, electric welding machines and capacitor banks. Contactors are divided into AC contactors (voltage AC) and DC contactors (voltage DC), which are used in electricity, power distribution and consumption.

The contactor is mainly composed of electromagnetic system, contact system, arc extinguishing system and other parts.

1) Electromagnetic system: The electromagnetic system includes the electromagnetic coil and core, which is an important part of the contactor, relying on it to drive the closing and disconnection of the contact.

2) Contact system: The contact is the executive part of the contactor, including the main contact and the auxiliary contact. The function of the main contact is to turn on.

3) Break the main circuit to control the larger current, and the auxiliary contact is in the control loop to meet the requirements of various control methods.

4) Arc extinguishing system: The arc extinguishing device is used to ensure that the arc generated can be reliably extinguished when the contact is disconnected from the circuit, so as to reduce the damage of the arc to the contact. In order to quickly extinguish the arc when disconnected, the contactor is usually equipped with an arc extinguishing device, which is generally a semi-sealed longitudinal seam clay arc extinguishing cover, and is equipped with a strong magnetic arc blowing circuit.

5) Other parts: insulating shell, spring, short circuit ring, transmission mechanism, etc.

Working principle: When the coil is energized, the static iron core produces electromagnetic attraction, and the moving iron core is sucked in, because the contact system is linked with the moving iron, so the moving iron core drives the three moving contacts to run at the same time, and the contact is closed, so as to connect the power supply. When the coil is powered off, the suction disappears, and the linkage part of the moving core is separated by the reaction force of the spring, so that the main contact is disconnected and the power supply is cut off.

The coil resistance of the contactor is a fixed value, and the voltage is high, and the current is smaller, (Ohm's law). The contact gap should be smaller.

Yes, the current received by the AC contactor contacts is related to the nature of the current itself (AC or DC, etc.) and not to the applied voltage. However, the contact spacing has a lot to do with the applied voltage. Of course, there is no problem with the use of 380V at 220V.

It is only related to the magnitude of the current, not the magnitude of the voltage.

The AC contactor generally refers to the switching element used for the start-stop operation control of the three-phase AC motor, which mainly has three pairs of main contacts and several groups of auxiliary contacts.

The three nominal indicators of the contactor are: coil working voltage, main contact rated current, auxiliary contact capacity and quantity.

1. a contactor.

The voltage of the main and coil contacts is not related to the auxiliary contact.

2. Contactors are divided into AC contactors and DC contactors, which are widely used in the switches of various power distribution and electrical equipment in the power system. The working principle of the contactor is: after the control loop of the contactor is energized, the coil current will produce a magnetic field, which makes the static iron core produce electromagnetic attraction to attract the moving core, and drives the AC connection main contact point to act, and completes the opening and closing of the control main contact contact, so as to achieve the purpose of controlling the load power equipment.

The coils of the control loop on the contactor are two completely different circuits from the auxiliary and main contacts. The coil of the control loop on the contactor is the same circuit as the auxiliary contact, and the voltage is the same. The main contact is a completely different circuit, and the voltage may be different from the control circuit.

The control loop can be the same voltage as the main loop or a different voltage than the main loop. In general, the low voltage controls the high voltage, which makes the system control more safe.

The contactor is actually one.

Set of switches. Each set of primary and auxiliary contacts is equal to a switch, like T1 L1 is a group, T2 L2 is a group, 21 22 , 11 12 and so on. Each set of contacts can be wired separately or in combination.

So their voltage depends on the power supply of the respective circuit. The coil voltage is the voltage that operates these switches, similar to automation control. His voltage depends on the contactor itself (the manufacturer sets it with more volts, then more volts).

It doesn't matter, the contactor control voltage is 220V and 380V, and the auxiliary contact and the main contact are two-way.

No! The control loop and the main loop are originally separate!

Hello: Li Li— 1,Contactor contact temperature rise.

The higher the current, the higher the temperature rise of the contact. The contacts of the contactor have contact resistance.

1. There is contact resistance between the dynamic and static contacts of the AC contactor, and it will heat up when the current flows, and the larger the current flowing, the higher the temperature rise of the contact. The contacts of the contactor have contact resistance. When an electric current passes through the contact resistance of the contact, a generating power is generated.

3. The main reasons for overheating the contacts are:

1) The current passing through the dynamic and static contacts is too large. The main reasons for the excessive contact current of the AC contactor are that the system voltage is too high or too low; overload of electrical equipment; Improper selection of contact capacity and faulty operation.

2) The contact resistance between the dynamic and static contacts of the AC contactor is too large. The reasons for the increase in contact resistance between contacts are:

a. Insufficient contact pressure. The contact pressure spring of the AC contactor loses its elasticity due to mechanical damage or arc high temperature, and the long-term wear and thinning of the contact will lead to a decrease in contact pressure and an increase in contact resistance. In this case, the pressure spring should be adjusted first, and if it does not work, the contact should be replaced with a new one.

b. Poor contact on the surface of the contact. The main reasons are:

Oil and dust form a resistive layer on the surface of the contact;

Oxidation of the copper contact surface;

1. There is no relationship between the temperature rise of the contactor contact and the voltage of the main circuit! On the contrary, it is related to the current flowing, and the higher the current, the higher the temperature rise of the contact.

2. The contacts of the contactor have contact resistance. When an electric current passes through the contact resistance of the contact, a heating power is generated: the square of the current, multiplied by the contact resistance, is equal to the heating power of the contact.

The working voltage of the contactor has a range, and the working voltage is about the same, and it is not a big problem. The working current should also be large enough.

That's how it is used, but the contactor also has a coil voltage that cannot be used to exceed or step down.

It is necessary to look not only at the rated voltage of the contactor coil, but also at the rated current of the electric shock used;

Under normal circumstances, the voltage is slightly higher and can be used, our factory voltage is 430V, 380V contactor can also be used, but it is best to come according to the nominal product.

As long as the supply voltage does not exceed the contactor calibration voltage, it is fine.

The contactor has an insulation voltage, as long as it does not exceed it.

In general, it can be used, but it is not very compliant.

The rated current and voltage of the coil refer to the parameters required for the normal engagement of the contactor;

Contact current and voltage ratings refer to the ability of the contactor to carry a load.

The relationship between the contactor coil energized and the suction (instantaneous) power and the holding (running after the engagement) power, current and voltage:

The rated current of the contact is related to the area of the contact, and the relationship between the load power and the current and voltage

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Please consult the product manual of the contactor, the technical indicators of the general contact include the connection capacity, breaking capacity, the curve relationship between the breaking voltage and the breaking current, etc.

Whether the 48V contact can be used in the 540V voltage circuit depends on the manual.

The main thing is to describe the maximum power of the contact.

This is for functional extensions, and it does not withstand high voltages.