SU1541684A1 - Device for investigation of heat flow diverted to contacts of electrical apparatus - Google Patents

Abstract

The invention relates to electrical engineering. The aim of the invention is to improve the accuracy of measuring heat fluxes. The device comprises a housing, a fixed contact holder 5 with a contact 6 and a temperature-sensitive flexible element 8, having an electrical connection to the current lead 10, which is attached to an insulating element 11 rigidly connected to the motor terminal 12 of the electromagnet 13, a movable contact holder 19 seconds contact 20, mounted on an insulating rod 21, rigidly connected to the passage of the bark 22 of the electromagnet 23. The current lead 10 is installed with the possibility of disconnection from the contact holder 5, which allows to exclude Essentially, the measurement error caused by heat removal through the current lead 10 into the current lead circuit. 1 il.

Description

The invention relates to an electrician, in connection with devices for examining the contacts of electrical apparatuses, and can be used to investigate the heat fluxes discharged into the contacts of electrical apparatuses when an electric arc is burning on them.

The purpose of the invention is to improve the accuracy of measuring heat fluxes.

The drawing shows a device for studying heat fluxes discharged into the contacts of electrical apparatus, a general view,

The device contains an insulating case made as a composite consisting of a support 2 fixed on the base 1, a chamber 3 and a partition C mounted between them. A fixed hollow cylindrical contact 5 with a contact b and 7 wound on its side surface 7 electrically insulated temperature changes by the flexible element 8 is installed in an insulating lid 9 fixed on Kymere 3. The fixed contact-holding body 5 is electrically connected to a 4-wire 10 which is attached to the insulating an element 11 connected by a motor with the propulsion bar 12 of the electromagnet 13 mounted on the insulating plate I. The insulating plate I is mounted on the Ht studs fixed in the base 1. The straight bore 12 is spring-loaded spring 1 (located between the washer 17 mounted on the bark 12, and an insulating plate 18 mounted on the studs 15.

The movable contact holder 19 with contact 20 is mounted on an insulating rod 21, which is rigidly connected to the motor wheel 22 of the electromagnet 23 mounted on the partition wall k. The front bore bore 22 is spring-loaded with a spring located between the adjusting nut 25 and the partition 4

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five

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In base 1, an abutment 26 is installed to limit the course of the prop path

22 electromagnet 23. To the movable contact holder 19 and the current supply

10, current leads 27 and 28 are connected, respectively. The stop 26 momet be made in the form of a microaInte.

The device works as follows.

When the electromagnet 2.3 is energized, its bore bore 22 moves towards the closure of contacts 6 and 20. The contact pressure is determined by the difference between the electromagnetic force acting on the bore 22 and the counteracting force of the spring 2. The electric circuit of the discharge circuit is formed by a current-carrying conductor 28, by a current lead 10, a fixed contact holder 5, contacts 6 and 20, a movable contact holder 19, and a current lead conductor 27. After applying a discharge current pulse from an electrical power source to the mouth after a specified period of time the electromagnet is de-energized

23 and under the action of the spring 2, the direct bore 22 moves in the direction of opening the contacts 6 and 20 up to the stop 26, and an electric arc arises at the contacts. Part of the energy of the electric arc in the form of heat is removed through the contact 6 into the contact holder 5 and is distributed along it by heat conduction. After that,

As the discharge current drops to zero, power is supplied to the electromagnet 13, while its pass-through measles 12 moves towards disconnecting the current lead 10 from the fixed contact holder 5. As a result, heat transfer from the contact holder 5 to the current supply 10 is prevented. The length of the fixed contact holder 5 is selected from condition that the temperature wave in the axial direction of the contact holder 5 does not reach the surface of its contact with the electrical power supply 10 until the contact holder b is disconnected from the electrical power supply 10. With the help The temperature resistance of the flexible element 8, for example copper wire with a diameter of 0.0 mm included in the Winston bridge diagonal, is determined by the resistance method by the average temperature in the heat-insulated stationary contact holder 5 after its alignment throughout the entire volume of contact holder 5. Based on the known heat capacity and variation The temperature of the contact holder 5 determines the amount of energy transmitted to the contact holder 5 through contact 6 when the electric arc is burning.

Heat flow q is determined from the following relationship:

q cm (TCP-THN (H),

where c is the heat capacity of the contact material

holder 5;

ha is the mass of contact coder 5; Tcp is the average value of the temperature of the contact holder 5 after the termination of arc burning and temperature equalization throughout the entire volume of the contact holder ii;

Tnom is the initial temperature of the contact holder 5 "To reset the installation to its original position, it is necessary to de-energize the electromagnet 13, while under the action of the spring Tb, the bore bore 12 with the current lead 10 moves before the contact with the fixed contact holder 5.

Thus, by comparison with the prototype, the proposed device provides an increase in the accuracy of measuring the heat fluxes discharged into the contacts of electrical apparatus.

Claims (1)

Invention Formula Device for the study of heat fluxes discharged into the contacts. electrical apparatus, comprising a housing, a movable contact holder 5 with a rod, fixed contact-holder, current-carrying movable and fixed contact-holders, electromagnet with a spring-loaded bark, rigidly connected with About the rod, characterized in that, in order to improve the accuracy of heat flux measurements, it is equipped with an additional electromagnet with a spring-loaded prop bar and a rod rigidly connected with the core, and a heat-sensitive flexible element, an additional electromagnet is mounted on the housing, the rods of both electromagnets are made from the insulating material, the fixed power lead for the fixed coke tamer is rigidly connected to the rod of the additional electromagnet, the fixed contact holder is cylindrical, and uvstvi5 Tel'nykh flexible element is disposed on the side surface of the stationary contact carrier and is electrically insulated from it.