JPS6029193Y2 - Protection device for electric heaters - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electric heater used for heating an air conditioner or auxiliary heating, or an overheating preventer for a general electric heater.

Figures 1 and 2 show a conventional overheat protector attached to an electric heater.

In the figure, 1 to 6 are heating elements of an electric heater, which are connected to each phase of a three-phase power supply.

7 is a heat dissipation fin, 8 is a casing in which 1 to 7 are fixedly assembled, and a temperature fuse 9, 9A is attached to two of the three phases.
- An overheat protector 10 provided with 9B is attached above the heating elements 1 and 2.

A indicates the heat flow from the heating element. When the blower of an air conditioner locks and stops during operation, the temperature fuse receives heat from heating elements 1 and 2 and melts, cutting off the circuit and preventing accidents. work to do.

In the conventional overheating preventer of an electric heater configured in this way, if the temperature fuse 9A of the phases of heating elements 1 and 2 is blown first in an abnormality such as when the blower of an air conditioner is locked, the heating element Since no heat is generated from the heat generating elements 1 and 2, the ambient temperature around the temperature fuse 9B decreases, and the heat generating elements 3 to 6 are operated in a single phase without blowing out the temperature fuse 9B.

As a result, the heating operation continues even though there is an abnormality, resulting in a drawback that complete protection is not provided.

The present invention aims to improve the above-mentioned drawbacks and improve safety performance by ensuring that both temperature fuses are always blown in the event of an abnormality.

In order to achieve the above-mentioned object, the present invention disposes a heating element 3.4, which is a common phase for two temperature fuses, just below the temperature fuses.

Hereinafter, one embodiment of the present invention will be explained with reference to FIG.

In FIG. 3, parts that are the same as or similar to those shown in FIG. 1 are denoted by the same reference numerals, and their explanations will be omitted.

Common phase 1 of the three-phase power supply with no temperature fuse connected
Two temperature fuses 9A and 9B connected to the other two phases 12 and 13 are disposed above one heating element 1 and 2.

Therefore, if the blower of the air conditioner stops for some reason during operation and the temperature near the heating element rises abnormally, even after one of the temperature fuses blows due to the heat, the common phase still remains. Since the heating element continues its heating action, the other temperature fuses are also blown by the heat.

According to the device explained above, even after one temperature fuse blows in the event of an abnormality, the other temperature fuse receives heat from the heating element, so it blows with almost no time lag from the first temperature fuse, improving safety performance. can be significantly improved.

Although the above explanation was given for the case of an electric heater used in an air conditioner, it is not limited to this only, and of course it can be used as a protection device for electric heaters using other three-phase power sources. .

[Brief explanation of the drawing]

Figure 1 is a general cross-sectional view of an electric heater for air conditioners, Figure 2 is a conventional wiring diagram corresponding to Figure 1, and Figure 3 is a diagram of the electric heater of the present invention shown in Figure 1. It is a corresponding wiring diagram. 1-6... Heating element, 9A, 9B... Temperature fuse, 10... Overheat preventer.

Claims (1)

[Scope of utility model registration request] In a protection device for an electric heater of an air conditioner in which the heating elements of each phase of a three-phase power supply are connected and a temperature fuse is connected to two phases of the three-phase power supply, the temperature fuse of the three-phase power supply is not connected. A protection device for an air heater of an air conditioner, characterized in that two temperature fuses connected to two phases are arranged on a common phase heating element.