JP3026879B2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner that operates while protecting a compressor.

[0002]

2. Description of the Related Art FIG.
682 is a circuit diagram showing an electric system of a conventional refrigerant compressor protection device disclosed in Japanese Patent Publication No. 682, 101a is a compressor motor, 106 is a crankcase heater, 107 is a thermostat, 107c is a contact point, and 108 is an electromagnetic contact. Container, 10
9 is an operation switch, and 110 is an auxiliary relay.

Next, the operation will be described. If the crankcase heater 106 is energized while the shield machine is stopped, the temperature of the compressor bottom becomes higher than the top temperature of the compressor due to the heating of the crankcase heater 106. When the voltage is applied to the auxiliary relay coil 110b, the auxiliary relay contact 110 is closed.
a is in a closed state. Therefore, if the operation switch 109 is turned on to operate the compressor, the coil 1
08b, the main circuit contact 108a closes and the compressor motor 101a is energized, and the compressor 101 operates.
During operation, the electromagnetic contactor auxiliary contact 108c is closed, the thermostat contact 107c is short-circuited, and the auxiliary relay contact 110a is always in the on state. Therefore, the compressor is not interrupted by the opening and closing of the thermostat contact 107c. Next, when the crankcase heater 106 is not energized while the compressor is stopped, the bottom of the compressor is not heated and there is no temperature difference between the bottom of the compressor and the top of the compressor. Therefore, the thermostat contact 107c is kept open. Since the auxiliary relay coil 110b is not energized, the auxiliary relay contact 11
0a is open, and even if the operation switch 109 is turned on, the electromagnetic contactor coil 108b is not energized and the compressor cannot operate. Further, even when the power supply circuit for the thermostat contact 107c is not energized, the auxiliary relay contact 110a is not attracted and the compressor cannot operate.

Another conventional example is disclosed in Japanese Patent Application Laid-Open No. 62-238.
937 and JP-A-61-175429.

[0005]

The conventional protection device for a refrigerant compressor, which is composed of a thermostat and an auxiliary relay, has a problem that it is difficult to mount and is expensive.

In a conventional air conditioner control apparatus disclosed in Japanese Patent Application Laid-Open No. 62-238937, a current detector for detecting a current value flowing through a compressor and a microcomputer for processing the current detected value by a microcomputer. Since a conversion circuit is required, there are problems such as a large number of components, a high cost of components, and poor component mounting and workability.

A conventional overload protection device for a compressor of an air conditioner disclosed in Japanese Patent Application Laid-Open No. 61-175429 is
If the overload protection set value is constant and the operation is performed with the receiving voltage shortage and the overload condition, the overload protection is activated continuously and the retry operation is continued. There has been a problem that the winding temperature rise becomes high and abnormal stoppage occurs due to protection of the winding temperature of the compressor.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an air-conditioning side protection device having a simple structure, excellent in mountability, and excellent in serviceability and reliability. Aim.

[0009]

An air conditioner according to the present invention includes a power supply for driving a compressor, a crankcase heater connected to the power supply and energized while the compressor is stopped. Current detection means for detecting the output current of the power supply device; determination means for determining whether or not the crankcase heater is abnormal based on the detection result of the current detection means; and the power supply device based on the determination result of the determination means. And shut-off means for shutting off the power supplied to the compressor from the compressor.

A power supply unit for driving the compressor, a winding temperature detecting means for detecting a winding temperature of the compressor, and a winding of the compressor based on a detection result of the winding temperature detecting means. Calculating an expected change temperature of the temperature, and when the calculation result exceeds a preset temperature value, shutoff supply means for supplying power after shutting off power supply from the power supply device to the compressor for a predetermined time, When the number of cut-offs of the cut-off supply means exceeds a preset number, a cut-off means for cutting off the power supplied from the power supply device to the compressor.

A power supply for driving the compressor, current detecting means for detecting an operating current of the compressor, and an operating current of the compressor are set in advance based on a detection result of the current detecting means. When the current value is exceeded, a power supply from the power supply device to the compressor for a predetermined period of time after the power supply to the compressor is supplied. Correction means for correcting the obtained current value, and interruption means for interrupting power supplied from the power supply device to the compressor when the interruption supply means is operated based on a correction result of the correction means. It is provided.

[0012]

The air conditioner according to the present invention detects an output current of a power supply device connected to a compressor and a crankcase heater which is energized while the compressor is stopped, and detects the output current of the crankcase heater from the detection result. Determine the presence or absence of abnormality,
Since the power supplied from the power supply device to the compressor is cut off based on the result of this determination, the device detects the operating current of the compressor.
It is possible to determine whether or not there is an abnormality in the crankcase heater that prevents the forming phenomenon at the time of starting the compressor, and to start and stop the compressor.

A power supply unit for driving the compressor; a winding temperature detecting means for detecting a winding temperature of the compressor; and a winding of the compressor based on a detection result of the winding temperature detecting means. Calculating an expected change temperature of the temperature, and when the calculation result exceeds a preset temperature value, shutoff supply means for supplying power after shutting off power supply from the power supply device to the compressor for a predetermined time, When the number of cutoffs of the cutoff supply means exceeds a preset number, the cutoff means for cutting off the power supplied from the power supply device to the compressor,
With a simple configuration, it is possible to reliably determine whether or not there is an abnormality in the compressor and to start and stop the compressor.

A power supply unit for driving the compressor, current detecting means for detecting an operating current of the compressor, and an operating current of the compressor are set in advance based on a detection result of the current detecting means. When the current value is exceeded, a power supply from the power supply device to the compressor for a predetermined period of time after the power supply to the compressor is supplied. Correction means for correcting the obtained current value, and interruption means for interrupting power supplied from the power supply device to the compressor when the interruption supply means is operated based on a correction result of the correction means. With this configuration, it is possible to start and stop the compressor with a simple configuration by reliably determining whether there is an abnormality in the compressor or an abnormality in the power supply unit.

[0015]

[Embodiment 1] Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. Figure 1
Shows a control configuration diagram. In the figure, 1 is a power supply, 2 is an input current detector used for overload control of the compressor 3, 5 is an electromagnetic contactor for turning the compressor 3 on / off, 7 is a crankcase heater 4 energized. A relay for turning on / off, 10 is a current detection signal waveform shaping circuit that shapes the input current detected by the current detector 2 and converts it into an analog amount, and 11 is an analog of the input current by the current detection signal waveform shaping circuit 10. A microcomputer that converts the converted value into a digital value and further has a function of abnormality determination processing software;
Reference numeral 12 denotes a control power supply circuit, and reference numeral 13 denotes a display lamp for reporting an abnormality. FIG. 2 is a time chart of the output of each lateral function block until the abnormality detection of the crankcase heater circuit. In the figure, symbol I1 is a signal obtained by converting the input current when the crankcase heater circuit is normal, and I2 is a signal obtained by converting the input current when the compressor 3 is operated. FIG. 3 shows a flowchart of the crankcase heater circuit abnormality detection. In the figure, a symbol I _(IN) indicates a value obtained by detecting an input current from the current detector 2, further converting the analog current into a digital value by the microcomputer 11, and an ICH in the microcomputer 11 by software processing. 5 shows comparison data of crankcase heater circuit abnormality determination.

While the crankcase heater is energized, an input current is detected by a current detector 2 used for overload control of the compressor 3, and the detection signal is converted into an analog signal and taken into a microcomputer 11.
In step 1, the analog input is converted into a digital signal, and the converted digital value is compared with a comparison data value of the crankcase heater circuit abnormality determination on software. If the detected digital amount is smaller than the comparison data value, it is determined that an abnormality has occurred.
At the same time, the stop state is maintained even if there is a command to start the compressor 3 to protect the compressor 3.

Embodiment 2 FIG. Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG.
FIG. 4 shows a control configuration diagram of an air conditioner according to Embodiment 2 of the present invention. In the figure, reference numeral 32 denotes a temperature detector of a winding incorporated in the compressor 3; 34, a detection circuit for converting the detected signal into a level detectable by the microcomputer 11;
Is a microcomputer having an A / D converter function for converting an analog temperature detection value into a digital value, 6 is an auxiliary relay for operating a coil power supply of the electrolytic contactor 5 for operating / stopping the compressor 3, and 13 is an auxiliary relay. An abnormal display at the time of lock failure, 12 is a control circuit power supply. FIG. 6 is a diagram showing changes in the current and winding temperature of the compressor in normal (normal) operation, overload, and locked state. FIG. 6 is a flowchart showing a process up to compressor lock detection.

The winding temperature of the compressor 3 is detected for each unit time (tB time) (steps 120 and 121), and a temperature change value is calculated at the time tB (ΔTn ← Tn-Tn-1) (step 122). The temperature change value ΔTn is compared with a reference temperature increase value ΔTF (winding temperature increase value when the compressor is locked × 0.9), which is a data table value of the microcomputer (step 123), and the temperature change value ΔTn> ΔTF If so, the compressor is stopped (step 124), and restarted three minutes after the stop (step 128). After starting, the above operation is performed. When ΔTn> ΔTF three times in a row (step 127), it is determined that the compressor lock is abnormal (step 1).
29) The power supply to the compressor 3 is kept stopped, and an abnormality is displayed.

Embodiment 3 FIG. Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. FIG.
Shows a control configuration diagram. 2 is a current detector used to protect the compressor 3, 10 is a current detection signal waveform shaping circuit for shaping the compressor current detected by the current detector 2 and mainly converting it to analog, and 555 is a shortage of power supply voltage A voltage detection circuit 11 converts the analog conversion value of the compressor current into a digital value by the current detection signal waveform shaping circuit 10, further determines whether or not undervoltage is detected, and sets an overload protection set value (IL or ILD). And a software function for performing overload protection control processing. FIG.
FIG. 3 shows a time chart of overload control in a case where the receiving voltage is an undervoltage and the overload operation state is set. Symbol IL
Is an overload protection set value when the receiving voltage is normal. ILD is an overload protection set value at the time of undervoltage.

Next, the operation will be described with reference to the flowchart of FIG. Detects undervoltage of received voltage during compressor operation, and when undervoltage, overload protection operation value is ILD
(Steps 521 to 523). When the outside air temperature becomes high and the overload operation state occurs, the compressor current ICM> I
When it becomes LD, start / stop electromagnetic contactor 5 for compressor 3
2c is turned off (steps 524 to 526), restarted after stopping for 3 minutes (steps 541 to 542). If the receiving voltage after restart is undervoltage,
The above protection operation is repeated. During this operation, the winding temperature of the compressor 3 does not rise to the protection operation value Tc. Next, when the receiving voltage is normal, the overload protection operation value is set to I
L is set (steps 522 and 531). When the overload operation state is reached and the compressor ICM> IL, the electric contactor 52c is turned off (steps 532 to 534), restarted after stopping for 3 minutes (steps 541 and 542). After the restart, the above-mentioned protection operation is repeated, and the overload protection operation is performed again. The overload protection operation is performed within the protection operation grace time, and abnormal stop is performed when the number of continuous NS operations is reached (steps 535 to 539).

[0021]

The air conditioner according to the present invention detects an output current of a power supply device connected to a compressor and a crankcase heater that is energized while the compressor is stopped, and detects a crank current from the detection result. Since the case heater abnormality is determined and the power supplied from the power supply device to the compressor is cut off based on the result of the determination, the crank which prevents the forming phenomenon at the time of starting the compressor by detecting the operating current of the compressor. Since the compressor can be started and stopped by judging the presence or absence of the abnormality of the case heater, an economical and highly reliable air conditioner that operates with the compressor protected by a small number of components can be obtained.

Also, a power supply device for driving the compressor, winding temperature detecting means for detecting a winding temperature of the compressor, and a winding of the compressor based on a detection result of the winding temperature detecting means. Calculating an expected change temperature of the temperature, and when the calculation result exceeds a preset temperature value, shutoff supply means for supplying power after shutting off power supply from the power supply device to the compressor for a predetermined time, When the number of cutoffs of the cutoff supply means exceeds a preset number, the cutoff means for cutting off the power supplied from the power supply device to the compressor,
Since it is possible to start and stop the compressor with a simple configuration by reliably determining whether or not the compressor is abnormal, a highly reliable air conditioner that operates while protecting the compressor can be obtained.

Further, a power supply device for driving the compressor, current detecting means for detecting an operating current of the compressor, and an operating current of the compressor are set in advance based on a detection result of the current detecting means. When the current value is exceeded, a power supply from the power supply device to the compressor for a predetermined period of time after the power supply to the compressor is supplied. Correction means for correcting the obtained current value, and interruption means for interrupting power supplied from the power supply device to the compressor when the interruption supply means is operated based on a correction result of the correction means. With this configuration, it is possible to start and stop the compressor with a simple configuration and reliably determine whether there is an abnormality in the compressor or whether there is an abnormality in the power supply unit. High air conditioner Obtained.

[Brief description of the drawings]

FIG. 1 is a control diagram of an air conditioner according to a first embodiment of the present invention.

FIG. 2 is a time chart of the air conditioner according to the first embodiment of the present invention.

FIG. 3 is a flowchart of the air conditioner according to the first embodiment of the present invention.

FIG. 4 is a configuration diagram of an air conditioner according to a second embodiment of the present invention.

FIG. 5 is a diagram showing current and winding temperature characteristics of a compressor of an air conditioner according to Embodiment 2 of the present invention.

FIG. 6 is a flowchart of a compressor abnormality detection of the air conditioner according to the second embodiment of the present invention.

FIG. 7 is a configuration diagram of an air conditioner according to Embodiment 3 of the present invention.

FIG. 8 is a time chart according to a third embodiment of the present invention.

FIG. 9 is a flowchart in Embodiment 3 of the present invention.

FIG. 10 is a control circuit diagram of a protection device for a refrigerant compressor in a conventional air conditioner.

[Explanation of symbols]

 2 Input Current Detector 3 Compressor 4 Crankcase Heater 5 Electromagnetic Switch 10 Current Detection Signal Waveform Shaping Circuit 11 Microcomputer 13 Error Indicator Lamp (Error Notification Means) 14 Fan Motor 32 Temperature Detector 34 Temperature Detector 55c Electromagnetic Switch 65 Power supply voltage undervoltage detection circuit 61 Compressor winding temperature abnormality detection circuit 62 Compressor winding temperature abnormality detector (contact) VL Undervoltage detection value IL Overload protection set value when receiving voltage is normal voltage ILD Power receiving Overload protection set value when voltage is undervoltage TC Set value of winding temperature protection of compressor

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yujiro Takano 3-18-1, Oka, Shizuoka-shi Mitsubishi Electric Corporation Shizuoka Works (72) Inventor Katsuhiko Saito 3-181-1, Oka, Shizuoka-shi Mitsubishi Electric (56) References JP-A-61-252464 (JP, A) JP-A-3-271649 (JP, A) JP-A-1-95255 (JP, A) Jpn. (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24F 11/02 102 E F25B 1/00 341 J F25B 1/00 341 K F25B 49/02 570 A

Claims (3)

(57) [Claims] 1. A power supply device for driving a compressor, a crankcase heater connected to the power supply device and energized while the compressor is stopped, and current detection means for detecting an output current of the power supply device. Determining means for determining the presence or absence of an abnormality in the crankcase heater based on the detection result of the current detecting means; and shutting off power supplied to the compressor from the power supply device based on the determination result of the determining means. And an air conditioner. 2. A power supply device for driving the compressor, a winding temperature detecting means for detecting a winding temperature of the compressor, and a winding of the compressor based on a detection result of the winding temperature detecting means. Calculating an expected change temperature of the temperature, and when the calculation result exceeds a preset temperature value, shutoff supply means for supplying power after shutting off power supply from the power supply device to the compressor for a predetermined time, An air conditioner comprising: shutoff means for interrupting power supplied from the power supply device to the compressor when the number of cutoffs of the cutoff supply means exceeds a preset number. 3. A power supply device for driving the compressor, current detection means for detecting an operation current of the compressor, and an operation current of the compressor set in advance based on a detection result of the current detection means. When the current value is exceeded, a power supply from the power supply device to the compressor for a predetermined period of time after the power supply to the compressor is supplied. Correction means for correcting the obtained current value, and interruption means for interrupting power supplied from the power supply device to the compressor when the interruption supply means is operated based on a correction result of the correction means. An air conditioner, comprising: