Calibration Structure and Calibration Method of Thermal Overload Relay Tripping Distance

Abstract

The invention discloses a calibration structure and a calibration method of thermal overload relay tripping distance. The calibration structure comprises a shell (1) which is provided with a bi-metal sheet (11) and a pedestal (2) which is provided with a tripping level (21). The pedestal (2) is slidably connected onto the shell (1). An adjusting piece (3) is arranged between the pedestal (2) and the shell (1). Indication marks are arranged on the adjusting piece (3) which is suitable for adjusting the sliding distance of the pedestal (2) relative to the shell (1). According to the calibration method of the tripping distance, with marking of coordination of the adjusting piece (3) and the shell (1) or the pedestal (2), the "equivalent tripping distance" is found and marked on the adjusting piece (3). The pedestal (2) slides relative to the shell (1) to an accurate calibration position via adjusting the aforementioned adjusting piece (3) according to a "zero drift power off tripping position" and the "equivalent tripping distance". The calibration structure is directly arranged on products so that adjustment of the calibration distance after zero drift is facilitated for users.

Description

technical field [0001] The invention belongs to the field of low-voltage electrical appliances, in particular to a calibration structure for the tripping distance of a thermal overload relay. Background technique [0002] Thermal overload relays are usually used in conjunction with AC contactors for thermal overload protection of motors. In the actual operation of the motor, such as dragging the production machinery to work, if the machine is abnormal or the circuit is abnormal and the motor is overloaded, the motor speed will drop, the current in the winding will increase, and the temperature of the motor winding will increase. raised. If the overload current is not large and the overload time is short, and the motor winding does not exceed the allowable temperature rise, this overload is allowed. However, if the overload time is long and the overload current is large, the temperature rise of the motor winding will exceed the allowable value, which will age the motor wind...

AI Technical Summary

Problems solved by technology

[0005] For this reason, the technical problem to be solved by the present invention is that the existing thermal overload relay tripping distance calibration method is unreasonable, which leads to poor calibration accuracy and low pass rate, and then provides a thermal overload relay tripping device with high calibration accuracy. Calibration structure for distance

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