JPH04177057A - Protection device for electric compressor in cooling system - Google Patents

Abstract

PURPOSE:To eliminate a repeated operation and stopping of an electric compressor for a long period of time and avoid a useless consumption of electrical power by a method wherein a counted value of a counter means is returned to its initial value when an intermittent operation is started again, and the restarting of operation of the electrical compressor with a temporary stopping means is prohibited when the counted value is higher than a predetermined value. CONSTITUTION:When an abnormal state in a cooling circuit is a temporary one and this abnormal state is eliminated, a normal intermittent operation of an electrical compressor 11 is restarted. The restarting of the normal intermittent operation is performed such that a temperature within a refrigerator reaches a cooling stopping temperature under an operation of the electrical compressor 11, the counted value is initialized to '0', resulting in that a judgment of abnormal state in the cooling circuit causes an increment of value of '1', the value is not increased so much and the abnormal state in the cooling circuit is removed, the cooling device is automatically returned to its normal operation. In turn, in case that the abnormal state in the cooling circuit is not a temporary one, the normal intermittent operation of the electrical compressor 11 is not restarted, and the temperature in the refrigerator does not reach the stopping of cooling operation. Due to this fact, the counted value is not initialized to '0', but the counted value is increased by '1' and the value exceeds a predetermined value. As a result, the electrical compressor keeps its stopped state.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a cooling device that maintains the internal temperature of refrigerators, freezers, etc. within a predetermined range by intermittently operating an electric compressor in a cooling circuit, and in particular, detects an abnormality in the operation of the cooling circuit and compresses the electric compressor. The present invention relates to a protection device for an electric compressor in a cooling system that is equipped with a temporary stop means for temporarily stopping the operation of the compressor and then restarting the operation of the compressor.

[Prior art]

Conventionally, this type of device includes an overload relay device made of bimetal in the power supply path to the electric compressor to form a cooling circuit, as shown in, for example, Japanese Utility Model Application Publication No. 59-7376. If the load on the electric compressor becomes abnormally large due to an abnormality in the operation of the cooling circuit, such as a clogged filter in the condenser or poor lubrication of the electric compressor, the power supply path will be turned off, and the system will automatically restart itself. In order to protect the electric compressor, the electric power supply line was turned on at the same time.

[Problem to be solved by the invention]

In the above-mentioned conventional equipment, if the abnormality in the operation of the cooling circuit is due to a temporary reason, the operation of the electric compressor is automatically restarted when the abnormality is no longer present. Restarting the compressor is preferred. However, unless the abnormality is caused by a temporary reason, the electric compressor will be repeatedly operated and stopped over a long period of time, resulting in a problem that the durability of the electric compressor will deteriorate. Further, there is also the problem that such repeated operation and stopping of the electric compressor results in extremely poor cooling efficiency and wasteful power consumption. The present invention was made to deal with the above-mentioned problem, and its purpose is to prevent the resumption of operation of the electric compressor unless the abnormality in the operation of the cooling circuit is caused by a temporary reason. An object of the present invention is to provide a protection device for an electric compressor in a cooling device, which improves the durability of the compressor and avoids wasteful consumption of electric power.

[Means to solve the problem]

In order to achieve the above object, the structural features of the present invention are as follows:
It is applied to a cooling system that maintains the temperature inside the refrigerator within a predetermined range by intermittently operating the electric compressor in the cooling circuit according to the output of a temperature sensor that detects the temperature inside the refrigerator, and detects abnormalities in the operation of the cooling circuit. In a protection device for an electric compressor in a cooling system equipped with a temporary stop means that temporarily stops the operation of the electric compressor and then resumes operation of the compressor, each time the operation of the electric compressor is stopped by the temporary stop means. a counter means for increasing the count value to add up the number of times of the same stop; an initialization means for returning the count value of the counter means to the initial value when intermittent operation of the electric compressor is resumed based on the temperature sensor output; A restart prohibiting means is provided which prohibits the temporary stopping means from restarting the operation of the electric compressor when the electric compressor becomes larger than the above value.

[Effect 1] In the present invention configured as described above, if the abnormality in the operation of the cooling circuit is due to a temporary reason, and the intermittent operation of the electric compressor based on the temperature sensor output is restarted, the count value will be reset to the initial value. Since the initial value is returned to the initial value when the intermittent operation of the electric compressor is restarted by the temperature sensor output by the counter means, even if the counter means increases the count value each time the electric compressor is stopped by the temporary stop means, the count value will not be large. It never becomes a value. As a result, in this case, the restart prohibition means does not prohibit the temporary stop means from restarting the electric compressor, so the electric compressor will continue to operate normally when the cooling circuit is no longer operating abnormally. controlled by. Further, unless the abnormality in the operation of the cooling circuit is due to a temporary reason, the intermittent operation of the electric compressor based on the temperature sensor output is not restarted, so the count value becomes a large value. As a result, in this case, the restart prohibition means prohibits the temporary stop means from restarting the operation of the electric compressor, so the operation of the same compressor that has been stopped by the temporary stop means will not be resumed, and the electric compressor will not start or stop. will not be repeated for a long time. [Effects of the Invention] As can be understood from the above description of the operation, according to the present invention, if the abnormality in the operation of the cooling circuit is due to a temporary reason, the operation of the electric compressor is not unnecessarily restricted. If there is no abnormality in the operation of the cooling circuit and the abnormality in the operation of the cooling circuit is not due to a temporary reason, the electric compressor will not have to start and stop repeatedly over a long period of time, improving the durability of the electric compressor. , it is also possible to avoid wasteful power consumption. [Embodiment] An embodiment of the present invention will be described below with reference to the drawings. Fig. 1 shows a block diagram of a cooling device for cooling the inside of a refrigerator or a freezer. This cooling device includes an electric compressor 11, a four-way valve 12, a condenser 13, a throttle 14, and an evaporator 15 that constitute a cooling circuit. The electric compressor 11, the four-way valve 12, the condenser 13, and the throttle 14 are provided outside the refrigerator or freezer, and the evaporator 15 is provided inside the refrigerator or freezer. An electromagnetic solenoid 12a is incorporated in the four-way valve 12,
When the solenoid 12a is not energized, the four-way valve 12 is set to the first state (the state shown in the figure), and the refrigerant pumped from the electric compressor 11 is circulated in the direction of the solid line arrow.
5 to cool the inside of the refrigerator. Further, when the electromagnetic solenoid 12a is energized, the four-way valve 12 is switched to the second state. The refrigerant pumped from the electric compressor 11 is circulated in the direction of the dashed arrow to defrost the evaporator 15. Electric power is supplied to the electric compressor 11 via power supply lines MLI to L3, and these power supply lines L
A main switch 21 that is turned on and off by a user's operation, and an electromagnetic contactor 22 that is turned on when the coil 22a is energized and turned off when the energization is removed are interposed in the l-L3. The coil 22a of the electromagnetic contactor 22 and the electromagnetic solenoid 12a of the four-way valve 12 are connected to the normally open contacts XI of the relay 23, 24,
It is connected between the power supply lines Ll and L3 via X2, and the inter-school point XI, x2 is connected to the coil
+, X2 is turned on and off by energization/de-energization. Relay 23.24 coil X +
, X2 is controlled by an electric control circuit 25, which is connected to a power supply line L2. An AC/DC converted DC voltage is supplied from a power supply circuit 27 connected to L3. The electric control circuit 25 is composed of a microcomputer with a built-in timer 25a, and the circuit 25 normally runs a "main program" corresponding to the flowchart shown in FIG.
When an interrupt signal is generated by the timer 25a, a "defrosting control program" corresponding to the flowchart in FIG. 3 is executed. Note that this timer 25a generates an interrupt signal several hours after being reset. The electric control circuit 25 includes an internal temperature sensor 31, an evaporator temperature switch 32, a case temperature switch 33, and a buzzer 34.
and a display 35 are connected. The internal temperature sensor 31 is provided inside the refrigerator or freezer, and detects the internal temperature T1 and outputs a detection signal representing the temperature TI. The evaporator temperature switch 32 is constituted by a temperature sensitive switch attached to the evaporator 15, and starts to turn on when the evaporator temperature T2 reaches the defrosting end temperature T2. Case temperature switch 33 is connected to electric compressor 1
Consists of a temperature sensitive switch attached to the case of 1.
It starts to turn on when the case temperature T3 reaches the operation stop temperature 73H, and turns off when the case temperature T3 reaches the operation restart temperature T3L (73H>T3L) while being turned on. The buzzer 34 and indicator 35 notify the user of an abnormality in the cooling circuit. Next, the operation of the embodiment configured as described above will be explained with reference to a flowchart. When the user turns on the main switch 21, the power supply circuit 2
7, DC voltage begins to be supplied to the electric control circuit 25,
The same circuit 25 executes the "main program" in step 4.
0, and initialization processing is executed in step 41. In this initial setting process, the temporary stop flag ST
P is initialized to "O" and count value N is initialized to "0". The temporary stop flag STP indicates whether or not an abnormality has been detected in the cooling circuit. It is set to "1" when an abnormality is detected, and is set to "O" when no abnormality is detected.
It is set to . The count value N represents the number of times the abnormality has been detected. Also, in this initial setting process, relays 23 and 24
The coils X + and X 2 are controlled to be de-energized, the buzzer 34 is set to a non-sounding state, and the timer 25a is reset. By de-energizing these coils X + , X 2 , normally open contacts X + , X of relays 23.24
2 is set to the off state, the coil 22a and the electromagnetic solenoid 12a are also not energized. As a result, the electromagnetic contactor 22 is set to the OFF state and no power is supplied to the electric compressor 11, so the compressor 11 is maintained in a stopped state. Further, the four-way valve 12 is maintained in the first state (the state shown). After this initial setting process, the program proceeds to step 42, and thereafter the electric control circuit 25 is operated in steps 42 to 48.
A circular process consisting of is repeatedly executed. In this circulation process, the electric control circuit 25 receives a detection signal from the internal temperature sensor 31 in step 42, and
The internal temperature T expressed by the detection signal in step 43
1 is equal to or higher than the cooling start temperature 718. In this case, if the internal temperature T is equal to or higher than the cooling start temperature T18 (time 3 t2.tj, l:s in Fig. 5A),
In step 43, it is determined that rYEsJ, and in step 44
Since the coil X of the relay 23 starts to pass through, the normally open contact X1 of the relay 23 turns on and the coil 22a
is energized and controlled. As a result, the electromagnetic contactor 22 is set to the ON state, so the electric compressor 11 starts operating and begins to force-feed the refrigerant to the four-way valve 12. Since the four-way valve 12 is now set to the first state, the refrigerant pumped from the electric compressor 11 circulates in the direction of the solid arrow, and
begins to cool down the inside of the refrigerator. After the process of step 44, step 45 “
After the abnormality check routine, the program returns to step 42, and after receiving the detection signal representing the internal temperature T1 in step 42, it is determined again in step 43 that the internal temperature T is equal to or higher than the cooling start temperature 718. Determine whether it exists or not. Now, with the start of cooling, the temperature inside the refrigerator T
1 begins to fall, so "N
Based on the determination that the internal temperature T1 is less than the cooling start temperature T11, it is determined in step 46 whether the internal temperature T1 is equal to or lower than the cooling stop temperature TIL. In this case, if the internal temperature T1 has not fallen sufficiently and is higher than the cooling stop temperature IL, the NO
'', the electric control circuit 25 performs step 42.
The circular process consisting of 43, 46, and 45 continues to be executed repeatedly. At this time, due to the cooling, the internal temperature T1 gradually decreases (from time 8 to t3 in FIG. 5A, from time t2 to t3).
tt～shi5. 6 to t7). During the circulation process, when the internal temperature T1 becomes lower than the cooling stop temperature TIL (time 1.+, ja in Fig. 5A,
t5), the electric control circuit 25 performs rY at step 46.
EsJ is determined, and the energization to the coil X of the relay 23 is canceled in step 47, so the normally open contact X1 of the relay 23 is turned off and the energization of the coil 22a is also canceled. As a result, the electromagnetic contactor 22 is set to the off state,
Since the electric compressor 11 stops operating and stops pumping the refrigerant, the cooling inside the refrigerator by the evaporator 15 stops. After the process of step 44, step 45 is performed as described above.
After the abnormality check routine j is processed, the program returns to step 42, and after receiving the detection signal representing the internal temperature T1 in step 42, the electric control circuit 25 again checks the internal temperature T1 in step 43. is equal to or higher than the cooling start temperature 718, and in step 46 it is determined whether or not the internal temperature T+ is equal to or lower than the cooling stop temperature Tit.In this case, due to the cooling stop, the internal temperature ■1 gradually increases from the cooling stop temperature T+t, so the rNO at steps 43, 46+, :
J. Based on the determination of "NO", the electric control circuit 25 again executes the circulation process consisting of steps 42, 43, 46.
．． t3～shi4. C5~tJ. Then, when the internal temperature T1 becomes equal to or higher than the cooling start temperature T++ again (time ti++t2+t4+ta in FIG. 5A), the electric control circuit 25 starts operating the electric compressor 11, as described above, and the compressor 11, the internal temperature T1 is maintained between the cooling start temperature TIH and the cooling stop temperature TIL. During such intermittent operation of the electric compressor 11, the electric control circuit 25 checks for an abnormality in the operation of the cooling circuit through the above-described "abnormality check routine" in step 45. The details of this "abnormality check routine" are shown in FIG. Determine whether or not. in this case,
If there is no abnormality in the cooling circuit consisting of the electric compressor 11, four-way valve 12, condenser 13, throttle 14, and evaporator 15, the temperature of the case of the electric compressor 11 will not become that high, and the case temperature switch 33 will turn on. Since it is off, the electric control circuit 25 determines "NO" in step 61, and determines rNOJ in step 70 based on the temporary stop flag STP, which is initially set to "0". At step 75, the execution of the "abnormality check routine" is terminated and the execution of the "main program" is started. As a result, if there is no abnormality in the cooling circuit, no substantive processing is performed in the "abnormality check routine." On the other hand, if the return of lubricating oil to the electric compressor 11 is poor or if the filter in the condenser 13 is clogged, the load on the electric compressor 11 will increase and the amount of heat generated by the compressor 11 will increase. The case temperature T3 of the compressor 11 increases. Furthermore, if the refrigerant in the cooling circuit leaks from any part, the amount of refrigerant returned to the electric compressor 11 will decrease, and the cooling effect of the refrigerant circulating in the electric compressor 11 will be cut off.
Case temperature T3 of electric compressor 11 increases. Due to the abnormal operation of the cooling circuit as described above, the case temperature T3 increases during operation of the electric compressor 11 and reaches the operation stop temperature 73H, and when the case temperature switch 33 is turned on (time j71j9+Fi in FIG. 5A), Electric control circuit 2
5 is determined as "rYES" in step 61, and determined as "rYES based on the temporary stop flag STP set in OII" in step 62, and the coil De-energize. As a result, as described above, the electromagnetic contactor 22 is turned off, power is no longer supplied to the electric compressor 11, and the compressor 11 is temporarily stopped. After the processing in step 63, the electric control circuit 25 starts energizing the buzzer 34 in step 64, and outputs an error display control signal to the display 35 in step 65. As a result, the buzzer 34 starts sounding and the display 35 displays an error message indicating that an abnormality has occurred in the cooling circuit, so that the user can recognize the abnormality. Next, the electric control circuit 25 adds "1" to the count value N in step 66, sets the temporary stop flag STP to "1" in step 67, and confirms that the count 4ft N is a predetermined value in step 68. The value NIIax (for example, "
3" or "4") is determined. Now, this count value N is a predetermined value N1. If it is less than or equal to
The electric control circuit 25 determines NOJ in step 68 and returns the program to step 61. In this case,
If not much time has elapsed since the electric compressor 11 stopped and the case temperature switch 33 is still in the on state, the electric control circuit 25 goes to step 61 to turn on the r
It is judged as YESJ, but the temporary stop flag STP is “1”
Since rNOJ in step 62 is set to
Based on this determination, the cyclic process consisting of steps 61 and 62 is repeatedly executed. During this time, since the electric compressor 11 is stopped, the case temperature T3 of the compressor 11 is gradually lowered by being cooled by the outside air (times 7 to 8 and 9 to jt++ and tz in Figure 5A). 2). In this way, when the case temperature T3 naturally decreases and reaches the operation restart temperature T3L (time t8 in FIG. 5A, t+
s, t++), the case temperature switch 33 is turned off, so the electric control circuit 25 executing the circulation process determines "NO" in step 61, and the temperature is set to "1" in step 70. rYESJ is determined based on the temporary stop flag STP, the processing consisting of steps 71 to 74 is executed, and the execution of the "abnormality check routine" is terminated at step 75. In step 71, energization of the coil X of the relay 23 is started, the electromagnetic contactor 22 is turned on again, and the electric compressor 1 which has been temporarily stopped
1 resumes driving. In step 72, the buzzer 3
4 is controlled to be stopped, and in step 73, the error display on the display 35 is controlled to be stopped. Further, in step 74, the temporary stop flag STP is changed to "IIO". After executing such "abnormality check routine", the electric control circuit 25 returns to the "main program" (FIG. 2).
is executed to start the above-mentioned rigid line operation of the electric compressor 11. In this case, the abnormality in the cooling circuit is temporary, and when the abnormality disappears, normal new line operation of the electric compressor 11 is resumed. The resumption of normal intermittent operation means that the temperature T in the refrigerator reaches the cooling stop temperature ■knee due to the operation of the electric compressor 11, and the time chart in FIG.
3), in this case, the "main program" (second
Based on the determination of rYESJ in step 46 of FIG. Even if the count value N increases by "1" in the process of step 66 (FIG. 4), the same value N will not increase by that much, and it will not be determined as rYEsJ in step 68. As a result, in this case, it is assumed that the abnormality in the cooling circuit has been removed, and the cooling device automatically returns to normal operation. On the other hand, if the abnormality in the cooling circuit is not temporary, the normal intermittent operation of the electric compressor 11 is not resumed, and the internal temperature T1 does not reach the cooling stop temperature TIL. Therefore, the count value N is not initially set to "O" by the process of step 48 of the "main program" (Fig. 2), and the count value N is not initialized to "O" every time the cooling circuit is determined to be abnormal in the "abnormality check routine". As a result of the process in step 66 (FIG. 4), the count value N increases by 1, and the count value N exceeds the predetermined value N.As a result, rYESJ is determined in step 68, and step Since the execution of all programs is stopped at step 69, the electric compressor 11 is maintained in a stopped state, the buzzer 34 continues to sound, and the display 35 maintains an error display. person is main switch 2
1 is turned off and then turned on again, execution of the "main program" is not started and operation of the electric compressor 11 is not restarted. This prevents the electric compressor 11 from being repeatedly operated and stopped for a long period of time, improving the durability of the compressor 11 and avoiding wasteful power consumption. Further, the user can always recognize abnormalities in the cooling circuit by the buzzer 34 and display 35. When several hours have passed since the start of operation of the cooling device, the timer 25a generates an interrupt signal, and the electric control circuit 25, which is currently executing the "main program", starts executing the "defrosting control program" shown in FIG. Starting at step 50,
At step 51, each coil of relay 23, 24
, Start energizing X2. As a result, the same relay 2
3. Normally open contacts XI and X2 of 24 turn on and coil 22a
Since the electromagnetic solenoid 12a is energized, the electromagnetic contactor 22 is turned on and power is supplied to the electric compressor 11, and the four-way valve 12 is switched to the second state (
Time ○ in Figure 5B, t2). In this state, the refrigerant pumped from the electric compressor 11 circulates in the direction of the broken line arrow, and the evaporator 15 generates heat, so that frost adhering to the evaporator 15 begins to be removed. After the processing in step 51, the electric control circuit 25 determines in step 52 whether or not the evaporator temperature switch 32 is in the on state. If not much time has passed since the start of defrosting, the electric control circuit 25 performs step 52.
Based on the determination that rNOJ at step 52.5
Continue repeating the cyclic process in step 3. This step 5
- Process 3 is the above-mentioned "abnormality check routine", and as mentioned above, if there is no abnormality in the cooling circuit, no substantial processing is performed in this routine. During this circulation process, the evaporator 15 continues to generate heat, so the evaporator temperature T2 gradually increases, and the frost adhering to the evaporator 15 is removed. On the other hand, during the 'a ring process, when the evaporator temperature T2 reaches the defrosting end temperature T2H at which defrosting is completed (at time l in Fig. 5B).
, t9), the evaporator temperature switch 32 is turned on, so the electric control circuit 25 determines "YESJ" in step 52, and after processing steps 54 to 56, steps 57
At step 54, the execution of the "defrosting control program" is finished, and the interrupted "main program J (Fig. 2)" is started again. At step 54, the coil X2 of the relay 24 is de-energized. , the normally open contact X2 of the relay 24 is turned off, the electromagnetic solenoid 12a is de-energized, and the four-way valve 12 is returned to the first state.Thereby, from now on, the refrigerant pumped from the electric compressor 11 flows in the direction of the solid line arrow. The evaporator 15 begins to cool the inside of the refrigerator as described above. In step 55, the timer 25a is reset and the timer 25a starts measuring time from the beginning again. Then, Several hours after the start of the measurement, the timer 25a generates an interrupt signal again, and the electric control circuit 25 executes the defrosting control program J again.In step 56, the count value N
is initialized to rOJ. On the other hand, if an abnormality occurs in the cooling circuit during this defrosting control, the electric control circuit 25 executes the same "abnormality check routine" processing as described above, as in the case during the cooling control described above. The operation of the electric compressor 11 is temporarily stopped, and then the operation of the compressor 11 is automatically restarted in cooperation with the case temperature switch 33 (time 2 to t8 in FIG. 5B). In this case as well, if the abnormality is temporary and the cooling circuit returns to normal, the evaporator temperature T2 reaches the defrosting end temperature 72H and the evaporator temperature switch 33 is turned on at the time shown in FIG. 5B. 9), the count value N is initialized to "O" by the process of step 56, so the same value N does not become too large, and the cooling device automatically returns to normal operation. Further, if the abnormality in the cooling circuit is not temporary, the count value N is not initially set to "O" as described above, but the same value N becomes large, and the rYEsJ in step 68 (FIG. 4) In other words, the count value N is the predetermined value N
It is determined that the value is larger than Mρ×, and the execution of all programs is stopped in step 69. As a result, as described above, the electric compressor 11 is maintained in a stopped state, improving the durability of the compressor 11 and also avoiding wasteful power consumption. In the above embodiment, an abnormality in the cooling circuit is detected based on the temperature of the case of the electric compressor 11.
As shown by the broken line in FIG. The overload of the compressor 11 may be directly detected by intervening in L3. In this case too,
When the load on the electric compressor 11 becomes large due to clogging of the filter in the condenser 13 or poor lubrication of the electric compressor 11, and an overcurrent flows through the compressor 11, the overload relay 37 is activated due to the temperature rise of the bimetal. Turn off the electric compressor 11
The power supply to the compressor 11 is cut off, and the operation of the compressor 11 is temporarily stopped. Further, after that, when the temperature of the bimetal decreases due to the interruption of the power supply, the overload relay 37 is turned on, the power supply is restarted, and the electric compressor 11 resumes operation. In this case as well, the number of activations of the overload relay 37 is counted as in step 66 (FIG. 4) of the above embodiment. In addition, as shown by the broken line in FIG. 1, a pressure sensor 38 is provided in the path of the refrigerant fed under pressure from the electric compressor 11, and by detecting the pressure in the path, refrigerant leakage can be detected from the condenser 13.
It may also be possible to detect an abnormality in the cooling circuit due to clogging of a filter in the cooling circuit. In this case, when the pressure detected by the pressure sensor 38 is abnormally low or abnormally high in step 61 (FIG. 4) of the above embodiment, it is determined that the cooling circuit is abnormal, and steps 62 to 6
After executing the process of 8 and detecting the abnormality once, the processes of steps 70 to 74 may be executed after a predetermined period of time.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a cooling device according to an embodiment of the present invention, FIGS. 2 to 4 are flowcharts of a program executed by the electric control circuit of FIG. 1, and FIGS. 5A and 5B.
The figure is a time chart showing the operation of the cooling device. Explanation of symbols 11...Electric compressor, 12...Four-way valve, 13...
・Condenser, 14... Throttle, 15... Evaporator, 22.
...Magnetic contactor, 23.24...Relay, 25...
Electrical control circuit, 31...Inner temperature sensor, 32...
Evaporator temperature switch, 33... Case temperature switch,
37... Overload relay, 38... Pressure sensor. Figure 2 Figure 3

Claims (1)

[Scope of Claims] Applied to a cooling device that maintains the temperature inside the refrigerator within a predetermined range by intermittently operating an electric compressor in a cooling circuit according to the output of a temperature sensor that detects the temperature inside the refrigerator, the cooling circuit In a protection device for an electric compressor in a cooling device, the protection device for an electric compressor in a cooling device is equipped with a temporary stop means that detects an abnormality in the operation of the electric compressor, temporarily stops the operation of the electric compressor, and then restarts the operation of the compressor. a counter means that increases a count value each time the electric compressor stops operating and adds up the number of times the electric compressor stops; and an initialization unit that returns the count value of the counter means to the initial value when the electric compressor resumes intermittent operation based on the output of the temperature sensor. and restart inhibiting means for prohibiting the temporary stopping means from restarting the operation of the electric compressor when the count value by the counter means becomes larger than a predetermined value. Protective device.