JPS6060038B2 - Refrigeration equipment compressor control circuit - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a control circuit for a compressor in a refrigeration device such as a refrigerator, and in particular, it has two compressors, and when the load is reduced, one compressor is stopped to perform capacity control operation. This invention relates to a compressor control circuit for a refrigeration system.

A conventionally known compressor control circuit for this type of refrigeration system is shown in FIG.

In the figure, 1 is a first compressor electromagnetic switch that operates and stops the first compressor;
It is connected in series to a low temperature side contact 2a which is a first contact of a temperature regulator 2 that senses the temperature of the object to be cooled. 3 is a second switch for starting and stopping the second compressor;
This is an electromagnetic switch for a compressor, and the second
It is connected in series to the high temperature side contact 2b which is a contact.

Note that in the first and second compressor electromagnetic switches 1 and 3, only the excitation coils are illustrated here. In such a configuration, when the temperature of the object to be cooled is higher than the set value of the high temperature side contact 2b of the temperature regulator 2 and the load is large, the contacts 2a and 2b of the temperature regulator 2 are closed, and the electromagnetic switch for the compressor is closed. 1,
3 is energized and both the first and second compressors are operating.

Further, when the temperature of the object to be cooled is lower than the set value of the low temperature contact 2b and there is no load, the contacts 2a and 2b are opened and the compressor electromagnetic switches 1 and 3 are deenergized and the first and second Both compressors have stopped. Next, the temperature of the object to be cooled is high temperature side contact 2b
lower than the set value of , higher than the set value of low temperature side contact 2a,
When the load is reduced, the high temperature side contact 2b opens and the second
The electromagnetic switch 3 for the compressor is deenergized to stop the second compressor, the low temperature contact 2a is closed, and the electromagnetic switch 1 for the first compressor is energized to stop only the first compressor. Driving. The temperature controller 2 operates as a load condition detector that detects the magnitude of the load based on temperature and opens and closes the energizing circuits of the first and second switches depending on the magnitude of the load. .

In this way, in conventional equipment, the order of starting and stopping the compressors is determined, and when the load is reduced, only the first compressor is operated to perform capacity control, so the operating time of the first compressor is shorter than that of the second compressor. The disadvantage was that the lifespan of the compressor was uneven, as it was longer than that of the conventional compressor.

The present invention has been made in order to eliminate such drawbacks, and provides a compressor control circuit for a refrigeration system that controls the drive of the first and second compressors so that their extended operating times are equalized. .

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

In the figure, 4 is a contact 4b, 4c that is activated by an electric motor 4a every time a predetermined period of time is accumulated.
The opening contact 1a of the first compressor electromagnetic switch 1 and the closing contact 3b of the second compressor electromagnetic switch 3 are connected in series, and the first compressor An energizing circuit in which a series circuit of the closing contact 1b of the machine electromagnetic switch 1 and the opening contact 3a of the second compressor electromagnetic switch 3 is connected is connected in series to the timer motor 4a. Further, the excitation coil of the first compressor electromagnetic switch 1, that is, the energizing circuit of the first switch is connected to the low temperature side contact 2 of the temperature regulator 2 via the timer contact 4b.
a or the high temperature side contact 2b, and the excitation coil of the second compressor electromagnetic switch 3 is connected in series to the high temperature side contact 2b. The energizing circuit of the switch is connected in series to the high temperature side contact 2b or the low temperature side contact 2a of the temperature regulator 2 via another contact 4c of the timer 4. In addition, timer contacts 4b, 4
c is when the first compressor electromagnetic switch 1 is connected to the low temperature side contact 2a! The second compressor electromagnetic switch 3 is connected to the high temperature side contact 2b, and when the first compressor electromagnetic switch 1 is connected to the high temperature side contact 2b, the second compressor electromagnetic switch 3 is connected to the high temperature side contact 2b.
The compressor electromagnetic switch 3 is configured to be connected to the low temperature side contact 2a. Next, the operation in the above configuration will be explained.

When the temperature of the object to be cooled is higher than the set value of the high-temperature side contact 2b of the temperature controller 2 and the load is large, the contacts 2a and 2b are closed, the compressor electromagnetic switches 1 and 3 are energized, and the The first and second compressors are both operating, the closing contacts 1b and 3b of the first and second compressor electromagnetic switches 1 and 3 are open, and the timer motor 4a is deenergized, and the timer 4 time will not be accumulated. In addition, when the temperature of the object to be cooled is lower than the set value of the low temperature side contact 2a of the temperature controller 2 and there is no load, the contacts 2a, 2
b is opened, and the compressor electromagnetic switches 1 and 3 are deenergized and the first
Both the compressors and the second compressor are stopped, the opening contacts Jla and 3a of the electromagnetic switches 1 and 3 for the first and second compressors are open, and the timer motor 4a is deenergized at this time as well. , the time of timer 4 is not integrated. Next, when the temperature of the cooled object is lower than the set value of the high temperature side contact 2b and higher than the set value of the low temperature side contact 2a and the load is being reduced, the high temperature side contact 2b opens and the low temperature side contact 2a closes. , either one of the first or second compressor electromagnetic switches 1 and 3 is energized and either the first or second compressor is operating, and the first or second compressor electromagnetic switch When the electromagnetic switch 1 is energized, the opening contact 1a of the first compressor electromagnetic switch 1 is closed, and the closing contact 3b of the second compressor electromagnetic switch 3 is also closed. When the second compressor electromagnetic switch 3 is energized, the opening contact 3a of the second compressor electromagnetic switch 3 is closed, and the closing contact 1b of the first compressor electromagnetic switch 1 is also closed. Since it is closed, the timer motor 4a is energized and the time of the timer 4 is accumulated. In this way, capacity control in which only the first or second compressor is operated is performed for a certain period of time, and when the timer 4 has integrated the predetermined time, the contacts 4b and 4c are switched.
Contact point 2a of compressor electromagnetic switch 1, 3 and temperature regulator 2,
Swap the connections of 2b. FIG. 3 is a time chart showing the above operation.

When the timer 4 is A, b, c, d, e, f, g, h, or i, the timer motor 4a is energized and the time is accumulated. Each time a preset constant value is reached, the contacts 4b and 4c are switched. For example in Figure 3, a+b=
c+d=e+f+g=h=-constant.

As described above, according to the present invention, since the operating time of either the first or second compressor is accumulated, one timer equalizes the operating time of each compressor. It is possible to extend the life of the compressor with a simple circuit configuration.

Furthermore, since the difference in operating time of both compressors is always within the set time of the timer, there is an effect that a highly reliable control device can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing a compressor control circuit of a conventional refrigeration system, Fig. 2 is a circuit diagram showing an embodiment of the present invention, and Fig. 3 is a time chart for explaining the operation of the present invention. . In the figure, 1 is a first electromagnetic switch for the compressor, 2 is a temperature regulator, 3 is a second electromagnetic switch for the compressor, and 4 is a timer.

Claims (1)

[Claims] 1 A first switch that operates and stops the first compressor, a second switch that operates and stops the second compressor, and a switch that detects the magnitude of the load and responds accordingly to the magnitude of the load. and a load state detector that opens and closes the energizing circuits of the first and second switches by the first and second contacts that operate, and when a load reduction is detected by the load state detector. In the compressor control circuit that performs capacity control operation by opening the energizing circuit of one switch and stopping one compressor, the first
energization in which a series circuit of the closing contact of the first switch and the opening contact of the second switch is connected in parallel to a series circuit of the opening contact of the switch and the closing contact of the second switch. energized through a circuit and connecting the first and second contacts and the first
and a second switch, the switching contacts are switched when the energizing circuit detects that the energizing circuit is energized for a preset period of time. 1. A compressor control circuit for a refrigeration system, comprising a timer for mutually switching connections between two contacts and the first and second switches.