What is a heating relay and what is a thermal relay used for?

There is no special term "heating relay", and the function of a relay for a certain line is to control the heating equipment, so it is called a heating relay.

There is also a theory that a certain line requires overload protection, and a thermal relay needs to be added.

Here's an explanation of what a thermal relay is:

When the deformation reaches a certain distance, it pushes the connecting rod to move and disconnect the control circuit, so that the contactor loses power and the main circuit is disconnected, so as to realize the overload protection of the motor. As an overload protection component of the motor, the relay has been widely used in production due to its small size, simple structure and low cost.

The function of the thermal relay is: it is mainly used to overload the asynchronous motor, and its working principle is that after the overload current passes through the thermal element, the bimetal sheet is heated and bent to push the action mechanism to drive the contact action, so as to disconnect the motor control circuit to realize the motor power-off and stop, and play the role of overload protection. Since it takes a long time for the heat to be transferred during the bending process of the bimetal sheet, the thermal relay cannot be used for short-circuit protection, but only for overload protection.

You should be talking about a thermal relay, or a relay that controls a heating device, so this relay is called a heating relay.

The working principle of the thermal relay is to generate heat by the current flowing into the heating element, so that the bimetal sheet with different expansion coefficients is deformed, when the deformation reaches a certain distance, the connecting rod action is promoted, the control circuit is disconnected, so that the contactor loses power, the main circuit is disconnected, and the overload protection of the motor is realized.

1. It is mainly used to carry out overload protection for asynchronous motors, and the working principle is that after the overload current passes through the thermal element, the bimetal sheet is heated and bent to push the action mechanism to drive the contact action, so as to disconnect the motor control circuit to realize the motor power-off and stop, and play the role of overload protection.

2. In view of the fact that it takes a long time for the heat to be transferred during the heating and bending of the bimetal sheet, the thermal relay cannot be used as short-circuit protection, but can only be used as the overload protection of the overload protection thermal relay.

Thermal relay is a kind of protective appliance that uses bimetal sheets to be heated and bent to push the contact action, which is mainly used for quick break protection of lines. The fault lies in the quick-break protection used for line tracks, which is not true. Thermal relays are used as overload protection elements for electric motors.

If the motor is overloaded, the current in the winding increases, the temperature of the bimetal sheet rises higher through the increase of the current in the thermal relay element, and the degree of bending increases, and the herringbone lever is promoted, and the herringbone lever pushes the normally closed contact, so that the contact is disconnected and the AC contactor coil circuit is disconnected, so that the contactor releases and cuts off the power supply of the motor, and the motor is stopped and protected.

The function of other parts of the thermal relay is as follows: the left arm of the herringbone lever is also made of bimetal sheet, when the ambient temperature changes, the bimetal sheet in the main circuit will produce a certain deformation and bending, and the left arm of the herringbone lever will also occur deformation and bending in the same direction, so that the distance between the herringbone lever and the attitude of the push rod is basically unchanged, and the accuracy of the thermal relay action is ensured. This effect is called temperature compensation.

The function of the <> thermal relay is to control the circuit to be disconnected, so it is often used as an overload protection hand element of the electric biju machine. The working principle of the thermal relay is that the current into the heating element generates heat, so that the bimetal sheet with different expansion coefficients is deformed, and when the deformation reaches a certain extent, it will cause the moving rod to act and repent, resulting in separation. The thermal relay is thus used to control the disconnection of the circuit, so that the contactor loses power, and there is no danger, so that the overload circuit is protected and the overload circuit is prevented from being damaged.