JPH07111295B2 - Abnormality display device of constant temperature machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant temperature machine such as a refrigerator or a freezer in which a temperature inside a refrigerator is maintained between an upper limit temperature and a lower limit temperature by alternately operating and stopping a cooling device. The present invention relates to an anomaly display device of a thermostatic machine that displays the anomaly when an anomaly occurs.

[0002]

2. Description of the Related Art Conventionally, an apparatus of this kind has been disclosed in, for example, Shokai Sho 6
As disclosed in Japanese Unexamined Patent Publication No. 0-10387, an abnormality detecting sensor for detecting a plurality of abnormalities occurring in a thermostat and an abnormality and its type are determined based on each detection signal from the sensor. An abnormality determination device is provided, and each abnormality determination device determines an abnormality and displays various abnormalities on a display device according to the type of the abnormality determined.

[0003]

However, in the above-mentioned conventional apparatus, the abnormality determination device needs to input each detection signal from a plurality of abnormality detection sensors, and the input circuit of the determination device is complicated. However, there is a problem that the manufacturing cost becomes high. The present invention has been made to solve the above problem, and an object of the present invention is to provide an abnormality display device for a thermostatic machine capable of detecting a plurality of abnormalities at low cost.

[0004]

In order to achieve the above object, the structural features of the invention according to claim 1 are: a temperature sensor for detecting the temperature inside the refrigerator; a cooling device for cooling the inside of the refrigerator; Cooling control means for controlling the alternating operation of the operation and stop of the cooling device based on the temperature inside the cold storage detected by the temperature sensor to maintain the temperature inside the cold storage between a predetermined upper and lower limit temperature. The thermostat is provided with contacts connected in series between two different voltages, and the contacts are normally kept in the ON state respectively, and different abnormalities of the cooling device are detected, and the contacts are turned OFF at the same detection time. A plurality of abnormality detecting means, a current detecting means connected in series to each contact of the plurality of abnormality detecting means to detect the presence or absence of a passing current, and a current passing means detects no passing current. And abnormal kind determination means for determining a type of abnormality in accordance with the operating condition of the can the cooling device is to provided a display means for displaying the type of abnormality based on the determination result.

Further, the structural feature of the invention according to claim 2 is different in the thermostatic machine equipped with the temperature sensor, the cooling device and the cooling control means of the invention according to claim 1.
A plurality of abnormality detections, each of which is provided with a contact connected in parallel between the voltages, keeps the contact normally in an off state, detects different abnormalities of the cooling device, and turns on the contact at the same detection time Means, a current detecting means that is connected to each contact of the plurality of abnormality detecting means in common and in series to detect the presence or absence of a passing current, and the cooling device is in the operating state when the passing current is detected by the current detecting means. The abnormality type determining means for determining the type of abnormality in accordance therewith, and the display means for displaying the type of abnormality based on the determination result are provided.

[0006]

In the invention according to claim 1 configured as described above, if there is no abnormality in the thermostat, the contacts of all the abnormality detecting means are kept in the ON state, so that the current detecting means. A passing current flows through. On the other hand, when an abnormality occurs in the thermostat, the contact of the abnormality detecting means corresponding to this abnormality is turned off. Then, each contact of the abnormality detecting means is connected in series, and if even one of the contacts is turned off, no passing current flows through the current detecting means, so that no passing current is detected by the current detecting means. The abnormality type determination means determines the type of abnormality according to the operating state of the cooling device. In this case, since various abnormalities can be detected according to the operating state of the cooling device, for example, immediately after the power is turned on, it is possible to detect the application of the anti-phase voltage due to the incorrect wiring of the compressor constituting the cooling device, Also, if a predetermined time or more has not passed from the operation of the cooling device, it is not possible to detect abnormal gas pressure due to clogging of the condenser, evaporator, etc. that make up the cooling device.
Also, when the compressor that constitutes the cooling device is started, it is possible to detect overload operation due to an abnormality of the compressor, so even if multiple abnormalities of the thermostat are detected together, the operating status of the cooling device The type of abnormality can be determined by taking into consideration. Then, the type of this abnormality is displayed on the display means.

Further, in the invention according to claim 2 configured as described above, if there is no abnormality in the thermostat, the contacts of all the abnormality detecting means are kept in the OFF state. No passing current flows through the detection means. On the other hand, when an abnormality occurs in the thermostat, the contact of the abnormality detecting means corresponding to this abnormality is turned on. Then, each contact of the abnormality detecting means is connected in parallel, and if even one of the contacts is turned on, a passing current flows through the current detecting means, so that the passing current is detected by the current detecting means, and the abnormality type determining means is detected. Determines the type of abnormality according to the operating state of the cooling device. In this case as well, as in the case of the invention according to claim 1, since various abnormalities can be detected according to the operating state of the cooling device, a plurality of abnormalities of the thermostat are collectively detected. However, the type of abnormality can be determined by considering the operating state of the cooling device. Then, the type of this abnormality is displayed on the display means.

[0008]

As can be understood from the above description of the operation,
According to the inventions according to claims 1 and 2, a plurality of abnormalities occurring in the thermostatic chamber can be discriminated, and in order to control the display on the display, the respective outputs of the plurality of abnormality detecting means are individually judged for the abnormality type. It is not necessary to lead to the means, the input circuit for the means is simplified, and the manufacturing cost can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows an entire thermostatic machine such as a refrigerator and a freezer by a block diagram.

This thermostat is an electric compressor 1 provided outside the refrigerator.
1, a condenser 12, a throttle 13, and an evaporator 1 provided in the refrigerator
4 is provided, and the refrigerant sent under pressure from the electric compressor 11 is circulated in the above order to cool the inside of the refrigerator by the evaporator 14. In the electric compressor 11,
Three-phase electric power is supplied from the power supply 15 through the overload relays 16 and the normally open contacts x ₁₁ , x ₁₂ , X ₁₃ of the relay 17. The overload relay 16 is normally on>
When an abnormally large current flows, it is turned off and the circuit is cut off. Normally open contacts x ₁₁ , x ₁₂ and X ₁₃ are relays 17.
The coil X ₁ is turned on / off by energizing / de-energizing it.

An electromagnetic valve 18 is provided between the discharge port of the electric compressor 11 and the upstream of the evaporator 14, and hot gas from the electric compressor 11 is supplied to the evaporator 14 when the valve 18 is in conduction. It is supposed to be done. Solenoid valve 1
8 is a power source 15 via normally open contacts x ₂₁ and x ₂₂ of the relay 19.
Are connected to two of the three-phase power supply lines from, and are set to the conductive state when the power is supplied and to the non-conductive state when the power is not supplied. The normally open contacts x ₂₁ and x ₂₂ of the relay 19 are adapted to be turned on / off by energizing / de-energizing the coil X ₂ of the relay 19.

Further, this thermostat is equipped with a pressure switch 21 and a reverse phase detector 22 for detecting an abnormality.
The pressure switch 21 is provided on the discharge port side of the electric compressor 11, that is, on the high pressure side, and is a normally closed contact 21a that is normally on and is turned off when the pressure on the high pressure side is abnormally high.
Built in. The negative phase detector 22 is connected to the three-phase power supply line between the power source 15 and the overload relay 16,
It has a normally closed contact 22a that is normally on and is turned off when a three-phase voltage of opposite phase is supplied to the electric compressor 11 due to a wiring mistake. These normally closed contacts 21a,
22a is connected in series with the coil X ₃ of the relay 23, and both ends of this series circuit are connected to two of the three-phase power supply lines in the overload relay 16. Relay 2
The coil X 3 of No. ₃ turns on the normally open contact x ₃₁ of the relay 23 when energized, and turns off the normally open contact x ₃₁ when de-energized.

The coils X ₁ and X _{2 of the} relays 17 and 19 and the normally open contact X ₃₁ of the relay 23 are connected to the microcomputer 30. A DC voltage is supplied to the microcomputer 30 from a power supply circuit 32 connected to the power supply 15 via a transformer 31, and the computer 30 operates by the supply of the DC voltage. In addition,
This DC voltage is applied to the display control circuit 35 and the display 36 which will be described later.
It is also supplied to.

The microcomputer 30 has a bus 30a.
ROM30b, CPU30c, R respectively connected to
It is composed of an AM 30d, a first timer 30e, a second timer 30f and an I / O 30g. The ROM 30b stores a program corresponding to the flowcharts of FIGS. 2 to 5, the CPU 30c executes the program, and the RAM 30d temporarily stores variables necessary for executing the program. The first timer 30e determines the cycle of defrosting and counts up after a predetermined time (for example, 6 to 8 hours) from the start of operation. The second timer 30f is used for detecting abnormality of the electric compressor 11, and counts up after a predetermined time (for example, 1 minute) from the start of operation. The I / O 30f is for exchanging signals with the outside.
In addition to the coils X ₁ and X _{2 of the} relays 17 and 19 and the normally open contact X ₃₁ of the relay 33, an internal temperature sensor 33, a defrost thermoswitch 34, a display control circuit 35, and a display 36 are connected.

The inside temperature sensor 33 is provided in the inside of a refrigerator or a freezer, and detects the inside temperature T and outputs a detection signal indicating the same temperature T. Defrost Thermo Switch 3
Reference numeral 4 denotes a temperature-sensitive switch attached to the evaporator 14, which is normally ON (when the cooling device is repeatedly operated and stopped) and is at a temperature at which the evaporator 14 completes defrosting. It turns off for the first time when it rises, and outputs a signal indicating this on / off state. The display 36 is composed of a liquid crystal display or the like for displaying alphanumeric characters, and is controlled by the display control circuit 35 to display the internal temperature T and the error codes E1 to E4 indicating the type of abnormality. There is.

Next, the operation of the embodiment configured as described above will be described. When a power switch (not shown) is turned on, a DC voltage is supplied from the power circuit 32 to the CPU 30c, the CPU 30c starts executing the program in step 100 of FIG. 2, and the cooling flag CFLG in step 101.
The set various variables in RAM30d including be initialized to the initial value "0", at step 102 the normally open contact X ₃₁ of the relay 23 determines whether OFF.
This determination process detects whether or not there is an abnormality in the thermostat, and if there is no abnormality in the thermostat, the normally closed contact 2
1a, 22a and the overload relay 16 are in the ON state, and the current flows through the coil X ₃ of the relay 23, so that the normally open contact X ₃₁ of the relay 23 is in the ON state.

First, the case where no abnormality occurs in the thermostat will be described. The CPU 30c makes a "NO" determination at step 102, and steps 103-108.
The cyclic process consisting of is repeatedly executed. In the circulation process, the CPU 30c first starts the operation of the first timer 30e in step 102, and determines whether the first timer 30e is counting up in step 104 (6 to 8 hours from the start of the operation). Has passed)
To judge. In this case, since the first timer 30e has just started to operate, it is determined to be "NO" in step 104, and the CPU 30c causes the step 30 to proceed.
In step 5, it is determined to be "YES" based on the cooling flag CFLG initially set to "0", and in step 106, the process of "operation stop routine" is executed.

This "shutdown routine" is shown in detail in FIG. 3, and the CPU 30c starts its execution at step 120, and at step 121 the inside temperature sensor 33.
Or by entering a detection signal representative of the internal temperature T, is equal to or higher than the upper limit temperature T _H of the temperature T is determined in advance (e.g., in the refrigerator -2 ° C., -17 ° C. In the freezer) from Determine whether or not. In the incubator, immediately after the power switch is turned on and the internal temperature T is equal to or higher than the upper limit temperature T _H , the CPU 30c causes “YES” in step 121.
Then, in step 122, the coil X _{1 of the} relay 17 is determined.
Energize and set the cooling flag CFLG to "1" in step 123.
In step 124, the operation of the second timer 30f is started, and in step 125, the process of the “operation stop routine” ends. As a result, the normally open contacts x ₁₁ , x ₁₂ , X ₁₃ of the relay 17 are set to the ON state, the electric power from the power source 15 is supplied to the electric compressor 11, and the compressor 11 starts its operation. Cold refrigerant is supplied to the evaporator 14 and the inside of the refrigerator begins to be cooled.

Next, the CPU 30c returns the program to step 104 of FIG. 2, and after determining "NO" in step 104, "NO" based on the cooling flag COLF changed to "1" in step 105. , "And executes the processing of the" cooling operation routine "in step 107. The details of this "cooling operation routine" are shown in FIG. 4, and the CPU 30c starts its execution at step 130, and the inside temperature T detected by the temperature sensor 33 at step 131 is the lower limit temperature _TL. Less than (eg,
In a refrigerator, it is -4 ° C, and in a freezer, it is less than -19 ° C). In this case, since the inside of the refrigerator has just begun to be cooled and the inside temperature T is equal to or higher than the lower limit temperature T _L , the CPU 30c determines “NO” in step 131, and the relay 23 of the relay 23 in step 132. based on the normally open contact X ₃₁ is on a determination of "NO", and outputs the display data representative of the internal temperature T in step 133 to the display control circuit 35, this "cooling step 134 The processing of the "operation routine" is ended. The display control circuit 35 controls the display 36 based on the display data, and the display 36 numerically displays the internal temperature T (for example, "-1.5 ° C").

After completion of the "cooling operation routine", the CP
U30c returns the program to step 104 of FIG.
After that, the circulation process including steps 104, 105, and 107 is repeatedly executed. During this circulation process, the relay 17
Since the coil X ₁ of the
The temperature T in the cold storage gradually decreases due to continuous cooling.
Further, the internal temperature T continues to be displayed on the display 36.

When the internal temperature T drops and falls below the lower limit temperature T _{L in} this way, the CPU 30c makes a "YES" determination at step 131 in FIG. 4 and the coil X _{1 of the} relay 17 at step 135. De-energize, step 1
At 36, the cooling flag CFLG is changed to "0", and at step 134, the process of this "cooling operation routine" ends. As a result, the normally open contacts x ₁₁ , x ₁₂ , X ₁₃ of the relay 17
Is set to the off state, the power supply from the power supply 15 to the electric compressor 11 is stopped, and the compressor 11 is stopped. Therefore, the cooling of the inside of the refrigerator by the evaporator 14 is stopped, and the inside temperature T
Begins to rise.

Next, the program is step 104 in FIG.
After the determination in step 104 is “NO”, the determination in step 105 is “YES” based on the cooling flag CFLG changed to “0”. Therefore, the circulation process including steps 104 to 106 is performed. Will be executed repeatedly. In this case, in the "outage routine" in step 106 (FIG. 3), until the internal temperature T is equal to or larger than the upper limit temperature T _H, CPU 30c Step 121
It is determined to be "NO" at step 126, and at step 126, the internal temperature T
Is output to the display control circuit 35. As a result, in this case, the operation of the cooling device is stopped and the inside temperature T gradually rises, and the inside temperature T continues to be displayed numerically on the display 36.

When the internal temperature T becomes equal to or higher than the upper limit temperature T _H , the CPU 30c causes the "operation stop routine" (FIG. 3).
It is determined to be “YES” in Step 121 of No. 121, and the inside of the refrigerator is started to be cooled by the processing of Step 122 described above. The circulation process made of these steps 104 to 107 (Fig. 2), operating and stopping are repeatedly controlled cooling apparatus, the internal temperature T is maintained between the lower limit temperature T _L and the upper limit temperature T _H.

On the other hand, during the circulation process consisting of the steps 104 to 107, 6 to 8 hours have passed and the first timer 30e
Is counted up, the CPU 30c executes step 10
It is determined to be “YES” in Step 4, and the processing of the “defrosting routine” is executed in Step 108. The details of this "defrosting routine" are shown in FIG.
The execution is started at 50, the operation of the second timer 30f is started at step 151, and the coil X _{1 of the} relay 17 is energized at step 152. As a result, even if the constant temperature machine is at rest and the electric compressor 11 is stopped,
The compressor 11 starts operating.

Next, CPU 30c based on the normally open contact X ₃₁ of the relay 23 in the ON state at step 153 determines as "NO", the display for indicating that a defrosting step 154 The data is output to the display control circuit 35, and the coil X _{2 of the} relay 19 is energized in step 155. As a result, the display control circuit 35 controls the display device 36 based on the display data, and the display device 36 displays the fact that defrosting is in progress (for example, "dF"). Also,
Since the normally open contact x _21, x ₂₂ of the relay 19 is set in the ON state, the valve 18 is turned on power is supplied from the power source 15 to the electromagnetic valve 18, hot gas from the compressor 11 is an electromagnetic valve It is supplied upstream of the evaporator 14 via 17. As a result, the temperature of the evaporator 14 starts to rise, and the frost attached to the evaporator 14 is removed.

After the processing of step 155, the CPU 30
In step 156, c determines whether or not the defrost thermoswitch 34 is in the off state. In this case, immediately after the defrosting is started, the temperature of the evaporator 14 is low and the defrosting thermo-switch 34 is in the ON state.
Is determined to be "NO", the temperature is increased to such an extent that defrosting is completed, and the circulation process including steps 153 to 156 is repeatedly executed until the defrosting thermoswitch 34 is turned off. During the circulation process, the display 36 displays the fact that defrosting is being performed, as described above.

[0027] Then, in the circulation process made of the step 153-156, the defrosting thermoswitch 34 is turned off, CPU 30c determines a "YES" in step 156, power supply to coil X ₂ of the relay 19 at step 157 Is canceled, and the processing of this "defrosting routine" is ended in step 158. As a result, the normally open contacts X ₂₁ , X ₂₂ of the relay 19 are turned off and the electromagnetic valve 18 is turned off, so that the supply of hot gas upstream of the evaporator 14 is stopped.

After completion of this "defrosting routine", the CPU 3
0c returns the program to step 103 of FIG. 2, starts the operation of the first timer 30e for the next defrosting in step 103, and operates and stops the cooling device by the circulation process including steps 104 to 107 described above. The alternate operation of is started again and the operation as described above is continuously controlled.

Next, a case where an abnormality occurs in the thermostat will be described. First, a case will be described in which a reverse phase voltage is applied to the electric compressor 11 due to a wiring error or the like when the thermostat is installed. In this case, when the power switch is turned on and the voltage of the reverse phase is supplied to the power supply line to the electric compressor 11, the normally open contact 22a of the reverse phase detector 22 is turned off. Thus, immediately after the power switch is turned on, the coil X _{3 of the} relay 23 is not energized and the normally open contact X
₃₁ turns off. As a result, the CPU 30c that started executing the program in step 100 of FIG. 2 immediately after turning on the power switch is “YES” in step 102 after the initialization processing of step 101, that is, the normally open contact X ₃₁ is off. It is determined that there is, and the display data representing “E4” is output to the display control circuit 35 in step 109, and step 1
At 10, the energization of the coils X ₁ and X ₂ of the relays 17 and 19 is prohibited, and at step 111, the execution of the program is stopped. As a result, the display control circuit 35 controls the display device 36 based on the display data, and the display device 36 displays the character "E4" indicating the application of the reverse phase voltage. Further, by prohibiting the energization of the coils X ₁ and X ₂ , the operation of the cooling device is prohibited.

Further, when a mechanical abnormality occurs in the electric compressor 11 and a large current flows into the electric compressor 11 when the electric compressor 11 is started, the overload relay 16 shuts off the power supply path. The electric power supply to the electric compressor 11 is stopped. At the same time, the overload relay 16, the normally closed contact 21a, 22a and so opens the ends of the closed path of the coil X ₃ are connected in series of the relay 23, the coil X ₃ is not energized, the normally open contact X ₃₁ Turn off. In this case, since the overload relay 16 reacts immediately after the electric current flows into the electric compressor 11, during the alternating operation of the operation and stop of the cooling device, that is, during the circulation processing of steps 104 to 107 of FIG. The abnormality is detected in the "cooling operation routine" of FIG. 4 immediately after the coil X _{1 of the} relay 17 is energized in step 122 of the "operation stop routine" of FIG. To be done. That is, after the determination of "NO" in step 131 of FIG. 4, the "YES" or normally open contact X ₃₁ is determined to be off at step 132, step 13
It is determined in 7 that "NO", that is, the second timer 30f has not counted up yet, the CPU 30c outputs the display data representing "E1" to the display control circuit 35 in step 132, and the relay in step 140. The energization of the coil X ₁ of 17 is stopped. As a result, the display control circuit 3
Reference numeral 5 controls the display device 36 based on the display data, and the display device 36 displays the character "E1" indicating the abnormality of the electric compressor. Also, by stopping the energization of the coil X ₁ ,
The cooling system stops operating.

On the other hand, in the defrosting operation of the cooling device, the abnormality of the electric compressor 11 is detected immediately after the second timer 30f is started in step 151 and the coil X _{1 of the} relay 17 is energized in step 152. To be detected. That is, in step 153, “YES”, that is, it is determined that the normally open contact X ₃₁ is off, and step 15
It is determined in 9 that "NO", that is, the second timer 30f has not yet counted up, the CPU 30c outputs the display data representing "E1" to the display control circuit 35 in step 160, and the relay in step 162. The energization of the coil X ₁ of 17 is stopped. As a result, the display control circuit 3
Reference numeral 5 controls the display device 36 based on the display data, and the display device 36 displays the character "E1" indicating the abnormality of the electric compressor. Also, by stopping the energization of the coil X ₁ ,
The cooling system stops operating.

Further, the condenser 12, the throttle 13, the evaporator 14
And, when a trapping abnormality occurs in these piping systems, that is, the refrigerant piping system, and the gas pressure on the high-pressure side rises to a predetermined pressure or more, the normally closed contact 21a of the pressure switch 21 is turned off,
The coil X _{3 of the} relay 23 is de-energized and the normally open contact X ₃₁ is turned off. In this case, even if the electric compressor 11 operates, the gas pressure does not suddenly increase. Therefore, during alternate operation of operation and stop of the cooling device, that is, during the circulation processing of steps 104 to 107 in FIG. , The coil X _{1 of the} relay 17 in step 122 of the "operation stop routine" of FIG.
Power to the second timer 30 in step 124.
The above-mentioned abnormality is detected in the "cooling operation routine" of Fig. 4 in which some time has elapsed since the start of operation of f. That is, after the determination of "NO" in step 131 of FIG. 4, "YES" in step 132, that is, the normally open contact X
₃₁ is determined to be off, and step 137
Is determined to be "YES", that is, the second timer 30f is counting up (about 1 minute has elapsed from the start of operation of the second timer 30f), and the CPU 30c determines that the step 1
The display control circuit 35 displays the display data representing “E2” at 39.
Output to the coil X _{1 of the} relay 17 in step 140.
Stop energizing. As a result, the display control circuit 35 controls the display 36 based on the display data, and the display 3
The letter "E2" indicating an abnormality in the refrigerant piping system is displayed at 6. Further, the operation of the cooling device is stopped by stopping the energization of the coil X ₁ .

Further, even if an abnormality such as a trapping abnormality occurs in the electromagnetic valve 18, the evaporator 14 and the piping system thereof, that is, the piping system of the hot gas, the gas pressure on the high pressure side rises to a predetermined pressure or more, The normally closed contact 21a of the switch 21 is turned off, the coil X _{3 of the} relay 23 is de-energized, and the normally open contact X ₃₁ is turned off. Also in this case, the electric compressor 11
The gas pressure does not suddenly increase even when is activated, so during the defrosting operation of the cooling device, that is, step 15 in FIG.
During the circulation process of 3 to 156 and 159 to 162, the second timer 30f is started in step 151 before the circulation process, and a little after the coil X _{1 of the} relay 17 is energized in step 152. After a lapse of time, the abnormality is detected. That is, in step 153, “YES”, that is, it is determined that the normally open contact X ₃₁ is off, and in step 159, “YES”, that is, it is determined that the second timer 30f is counting up, the CPU 30c determines that In step 161, display data representing “E3” is output to the display control circuit 35, and step 1
At 62, the energization of the coil X ₁ of the relay 17 is stopped. As a result, the display control circuit 35 controls the display device 36 based on the display data, and the display device 36 displays the character "E3" indicating an abnormality in the hot gas piping system. Also,
The defrosting operation is stopped by stopping the energization of the coil X ₁ .

As can be understood from the above description, according to the above embodiment, the overload relay 16 and the normally closed contact 21a of the pressure switch 21 for detecting various abnormalities of the constant temperature machine.
And the normally closed contact 22a of the reverse-phase detector 22 as well as connected in series, the coils X ₃ of the relay 23 interposed in the series circuit, the relay 23 energized and non-energization to the coil X ₃
Since it is detected by turning on / off the normally open contact X ₃₁ of the above, it is guided to the I / O 30g of the microcomputer 30,
I / O 30g input lines can be reduced
O30g itself can be easily configured. Moreover, since the timing of occurrence of the various abnormalities varies depending on the operating state of the cooling device as described above, the type of abnormality can be determined by considering the operating state, and this type indicates the error code E1.
Since they are displayed as ~ E4, even if an abnormality occurs in the thermostat, the user and the repairer can take appropriate measures.

Next, another embodiment of the present invention in which a part of the above embodiment is modified will be described. In this embodiment, as shown in FIG. 6, the pressure switch 21, the reverse phase detector 22 and the overload relay 37, which operate in the same manner as in the above embodiment, have normally open contacts 21b, 22b, 37a. The contacts 21b, 22b, 37a are normally off and are turned on only when there is an abnormality in each part. These normally open contacts 21b, 22
b and 37a are connected in parallel between the two power supply lines connected to the power supply 15. Also, each of these normally open contacts 2
Between the 1b, 22b, 37a and one power supply line, the relay 3 is commonly and serially connected to the same contacts 21b, 22b, 37a.
Eight coils X ₄ are connected. This coil X ₄
The energization turns on the normally open contact x ₄₁ of the relay 23 connected to the I / O 30g, and the deenergization turns off the normally open contact x ₄₁ .

With such a configuration, all the normally closed contacts 21 can be provided if no abnormality has occurred in the thermostat.
Since b, 22b and 37a are off, the coil X _{4 of the} relay 38 is kept in a non-energized state and the normally open contact X ₄₁ is kept in an off state. On the other hand, the gas pressure abnormality on the high-pressure side, the power supply abnormality due to the reverse phase, and the electric compressor 11 as in the above-described embodiment
If any one of the overload abnormalities occurs, one of the normally closed contacts 21b, 22b, 37a corresponding to the generated abnormality is turned on, the coil X ₄ is energized, and the normally open contact X ₄₁ is turned on. Therefore, in the case of this embodiment, the CPU 30c of the microcomputer 30 executes the step 10 of FIG.
2, instead of the determination process of step 132 of FIG. 4 and step 153 of FIG. 5, the steps 102, 132, 1
A program obtained by modifying the program of the above-described embodiment so as to determine whether or not the normally open contact X ₄₁ is turned on at 53 may be executed. According to this, the same effect as that of the above-described embodiment can be expected in the other embodiments.

[Brief description of drawings]

FIG. 1 is an overall schematic block diagram of a thermostatic machine showing an embodiment of the present invention.

2 is a flowchart of a program executed by the microcomputer of FIG.

FIG. 3 is a detailed flowchart of an operation stop routine of FIG.

FIG. 4 is a detailed flowchart of the cooling operation routine of FIG.

5 is a detailed flowchart of a defrosting routine of FIG.

FIG. 6 is an overall schematic block diagram of a thermostatic machine showing another embodiment of the present invention.

[Explanation of symbols]

11 ... Electric compressor, 12 ... Condenser, 13 ... Throttle, 14 ...
Evaporator, 16, 37 ... Overload relay, 17, 19, 2
3, 38 ... Relay, 18 ... Electromagnetic valve, 21 ... Pressure switch, 22 ... Reverse phase detector, 30 ... Microcomputer, 33 ... Chamber temperature sensor, 34 ... Defrosting thermoswitch, 36 ... Indicator, 21a, 22a … Normally closed contact, 21
b, 22b, 37a ... Normally open contact.

Claims (2)

[Claims] 1. A temperature sensor for detecting a temperature inside the refrigerator, a cooling device for cooling the inside of the refrigerator, and an alternating operation of operating and stopping the cooling device is controlled based on the temperature inside the refrigerator detected by the temperature sensor. In a thermostatic machine equipped with a cooling control means for maintaining the internal cold storage temperature between a predetermined upper limit temperature and a lower limit temperature, the constant temperature machine is provided with contacts connected in series between two different voltages. A plurality of abnormality detecting means for respectively keeping the on-state and detecting different abnormalities of the cooling device and turning off the respective contacts at the same time, and connected in series to each contact of the plurality of abnormality detecting means Current detection means for detecting the presence or absence of a passing current, and an abnormality type judgment for determining the type of abnormality according to the operating state of the cooling device when the absence of a passing current is detected by the current detection means. An abnormality display device for a thermostatic machine, comprising: determining means and display means for displaying the type of abnormality based on the determination result. 2. A temperature sensor for detecting a temperature inside the refrigerator, a cooling device for cooling the inside of the refrigerator, and an alternating operation of operating and stopping the cooling device is controlled based on the temperature inside the refrigerator detected by the temperature sensor. In a thermostatic machine having cooling control means for maintaining the internal cold storage temperature between a predetermined upper limit temperature and a lower limit temperature, a constant temperature machine is provided with contacts connected in parallel between two different voltages. A plurality of abnormality detecting means for respectively keeping different states of the cooling device while keeping the respective states in an off state, and for making the contacts respectively in an on state at the same detection time, and commonly and serially connected to respective contacts of the plurality of abnormality detecting means A current detecting means for detecting the presence or absence of a passing current, and a difference for judging the type of abnormality according to the operating state of the cooling device when the passing current is detected by the current detecting means. An abnormality display device for a thermostatic machine, comprising: a constant type determination means and a display means for displaying a type of abnormality based on the determination result.