SU1529310A1 - Protection device - Google Patents

Abstract

FIELD OF THE INVENTION The invention relates to electrical engineering, namely, protection devices against unacceptable heat. The aim of the invention is to simplify maintenance. The protection device contains a temperature-sensitive element of a material with a reversible shape memory in the form of a spring suspended on a ledge of a spring-loaded contact bridge, made with the possibility of rotation around an axis located below the ledge. Under the contact bridge there is a surface of the support of the free end of the thermosensitive element with two symmetrically located recesses. Two fixed contacts corresponding to the moving contacts on the bridge are intended to be connected to a switch located outside the protected installation. 2 Il.

Description

The invention relates to electrical engineering, in particular, to protection devices against unacceptable heating, and can be applied to protect electric heaters in vessels for boiling water.

The aim of the invention is to simplify the maintenance of the device for protection against unacceptable heat.

Figure 1 shows schematically the proposed protection device; Fig. 2 is a diagram of the inclusion of a protection device in the power supply circuit of the protected installation.

A thermosensitive element 1 made of a material with a reversible shape memory is suspended on a protrusion 2 of a contact bridge 3 rotating around axis 4. On the side opposite to the placement of thermosensitive element 1, a spring 5 abuts against protruding 2 On the insert 6 of insulating material there are fixed contacts 7 and 8. The recesses 9 and 10 in the lower part of the liner 6 are separated by a low partition 11. The liner 6 is installed in the upper part of the radiator 12, covering the protected heating element 13. The switch 14 is located outside the protected device.

Under normal operating conditions, the temperature-sensitive element 1 is heated to a temperature below the temperature of change of shape and hangs on the ledge 2 so that its free end does not reach the surface of the recess 9. At the same time, the contact bridge 3, galvanically connected to the heating element 13, closes

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contact 7 in series with switch 14 (in the position shown in Fig. 2) the power supply circuit of the heating element 13. If the temperature of the heating element 13 rises to an unacceptable value; for example, due to the lack of water in the vessel in which the heater is installed, it simultaneously heats up the radiator 12 from the time, and the temperature-sensitive element 1 from it to the temperature of its shape change. The temperature-sensitive element 1 is made in the form of a spring, which expands when heated by the SRI. When straightening, the thermosensitive element 1 abuts against the bottom of the bottom 9. With further expansion, element 1, overcoming the force of the wire, turns the contact plug 3 counterclockwise around axis 4 and pulls the bridge 3 away from pin 7. B During the rotation, the contact bridge 3 passes through the position of maximum compression of the spring 5, the distributor further straightens and thickens the bridge 3 before contacting it with a fixed contact 3. Since the position of the switch 14 remains unchanged, the supply circuit of the heating element 13 is the in- shets razoschnutoy. As a result of the opening, the Cesc's origin is cooling of all the parts of the device. Temperature sensor 1 for

As the protrusion 2 moved to the position above the angle of motion, passes through the partition 11, and the temperature-sensitive element 1 is suspended above the recess 10, just as before: it was suspended above the "recess 9." As a result, the protection device turns out to be | again prepared for the implementation of its functions. Switching it on and the device to be protected (in the case of heating element 13 in question) after the activation has been performed. ate y.

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Perhaps another design of the proposed protection device. In particular, a radiator | DNP of heat transfer from its source to a temperature-sensitive element is not always necessary. The device does not necessarily have to break the power supply circuit of the device itself, its contacts can be included in the power supply circuit of the contactor coil, starter or independent circuit breaker.

However, a prerequisite for its use is the unchanged orientation of the device being protected, since the operation of the protection device is based, in particular, on the effect of gravity moving the free end of the thermosensitive element.

The ability to remotely turn on the proposed protection device after it has been triggered greatly simplifies the maintenance of the protected equipment operating. in a constant position without changing the slope. In this regard, the device is conveniently provided with a dp protection of heaters in vessels intended for boiling water.

Claims (1)

Claims of protection against inadmissible heating, containing a temperature-sensitive element of a material with a reversible shape memory and a contact system, characterized in that, in order to simplify servicing, the contact system is formed by a spring-loaded rotatable contact bridge with two symmetrically positioned ISCBS contacts and two fixed contacts corresponding to these contacts, and the temperature-sensitive element is a spring suspended at one end on and a contact bridge above the axis of its rotation, with the support surface of the thermosensitive element located below the contact bridge, designed with two symmetrically located recesses. / J 1 -AND 1C Phie. 2