JPH05256543A - Operational failure detector for air conditioner - Google Patents

Abstract

PURPOSE:To obtain a low cost mechanism capable of preventing an abnormal rise in high voltage with simple structure. CONSTITUTION:In an air conditioner which drives a compressor 1 with an induction motor 10 driven at a commercial frequency, there are installed an input current detection means 12 which detects an input current to the induction motor 10 and a control means 13 which decides the pressure on the discharge side of the compressor 1 as an abnormal rise when the detected current exceeds a reference value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abnormality detecting device for an air conditioner.

[0002]

2. Description of the Related Art In a heat pump system for condensing and evaporating the refrigerant discharged from a compressor, if the fan on the condenser side is damaged or locked, the refrigerant discharged from the compressor is 1.5 times the design pressure. An abnormal increase in pressure occurs to a certain degree. Therefore, in the past, for example, actual exploitation 63
A pressure switch HPS was used, as also described in US Pat. This is a structure that detects the pressure in the discharge pipe of the compressor, turns off the contact when the detected pressure exceeds the set pressure, and turns on the contact when the pressure drops below the set pressure. The compressor, outdoor fan, indoor fan, etc. are stopped by this to ensure the safety of the device.

[0003]

By the way, in the conventional structure using the pressure switch as described above, since it is necessary to mount the switch on the discharge pipe, the structure of the refrigerant circuit becomes complicated, and for that reason, a large amount of it is required. There is the problem of cost.

The present invention has been made to solve the above-mentioned conventional drawbacks, and an object thereof is to provide an abnormality detecting device for an air conditioner capable of simplifying the refrigerant circuit configuration and reducing the cost. To provide.

[0005]

Therefore, the abnormality detecting device for an air conditioner according to claim 1 is an air conditioner in which the compressor 1 is operated by the induction motor 10 driven at a commercial frequency. Input current detecting means 12 for detecting an input current to the compressor, and control means for determining that the pressure on the discharge side of the compressor 1 has abnormally increased when the detected current is a reference value or more and outputting an abnormal signal. It is characterized by having 13.

[0006]

There is a close correlation between the pressure on the discharge side of the compressor 1 and the input current to the induction motor 10. Therefore, if the input current is detected as in the first aspect, the pressure on the discharge side of the compressor 1 can be grasped, and thereby the abnormal pressure rise can be detected.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, specific embodiments of an abnormality detecting device for an air conditioner according to the present invention will be described in detail with reference to the drawings.

In FIG. 1, reference numeral 1 is a compressor, the discharge pipe and suction pipe of which are connected to the primary port of a four-way switching valve 2. A refrigerant circulation path 6 in which an outdoor heat exchanger 3, a capillary tube 4, and an indoor heat exchanger 5 are interposed is connected to the secondary port of the four-way switching valve 2, and the refrigerant discharged from the compressor 1 is discharged. While performing the cooling operation by condensing in the outdoor heat exchanger 3 and evaporating in the indoor heat exchanger 5, heating operation is performed by condensing in the indoor heat exchanger 5 and evaporating in the outdoor heat exchanger 3. There is. Reference numeral 7 indicates an outdoor fan, and 8 indicates an indoor fan.

The compressor 1 is of a non-inverter type, that is, driven by an induction motor 10 driven by a commercial frequency. A power input circuit 11 to the induction motor 10 has a current transformer serving as a current detecting means. 12 is arranged so that the input current to the induction motor 10 can be detected. 13 is CP
U, a control unit (control means) including a memory,
It is for controlling the operations of the induction motor 10, the outdoor fan 7, and the indoor fan 8 based on the detected current.

The control contents of the control unit 13 will be described with reference to FIG. First, the input current value is detected by the current lance 12 (step S1), and this is compared with the reference value (step S2). If the input current value is smaller than the reference value, the operating state is continued as it is, and if the input current value is the reference value or more, an abnormal signal is output,
The induction motor 10, that is, the compressor 1 is stopped, and the indoor fan 8 and the outdoor fan 7 are stopped (step S).
3). As shown in FIG. 3, there is a certain correlation between the input current (operating current) to the induction motor 10 and the pressure (high pressure) on the discharge side of the compressor 1, and the input current value Is higher than the reference value, it can be determined that the high pressure is abnormally increased.

Since the abnormal increase in the high pressure can be detected by detecting the input current value as described above, it is not necessary to attach the pressure switch to the discharge pipe while securing the safety of the device as in the conventional case. Therefore, the refrigerant circuit can be simplified and the cost can be reduced.

[0012]

As described above, according to the abnormality detecting device for the air conditioner of the first aspect, it is determined whether or not the discharge side pressure of the compressor has abnormally increased based on the input current to the induction motor. Therefore, it is not necessary to mount the pressure switch on the discharge pipe while securing the safety of the device as in the conventional case, so that the refrigerant circuit can be simplified and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of an abnormality detection device for an air conditioner according to the present invention.

FIG. 2 is a flowchart of a control procedure in the above embodiment.

FIG. 3 is a graph showing the relationship between input current and high pressure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 10 Induction motor 12 Current transformer (current detection means) 13 Control unit (control means)

Claims (1)

[Claims] 1. An air conditioner for operating a compressor (1) with an induction motor (10) driven at a commercial frequency, wherein an input current detecting means for detecting an input current to the induction motor (10). 12) and a control means (13) for determining that the pressure on the discharge side of the compressor (1) has risen abnormally and outputting an abnormal signal when the detected current is a reference value or more. An air conditioner abnormality detection device.