Outdoor unit of an air conditioning system

Abstract

Outdoor unit (1) of an air conditioning system, comprising: a housing (2) made of a first metal, wherein the housing (2) has a box shape; a heat exchanger (6) arranged in the housing (2) and attached to the housing (2) via a non-conductive material (7), wherein at least a part of the heat exchanger (6) is made of a second metal, wherein the second metal is different from the first metal with respect to its intrinsic potential; and a conductive material (3) made of a non-metal, wherein the conductive material (3) is arranged in the housing (2), wherein the conductive material (3) is attached to the housing (2) and electrically connected to the housing (2) and electrically connected to the heat exchanger (6).

Description

Technical area

[0001] The present disclosure relates to an outdoor unit of an air conditioner, the outdoor unit comprising a housing and a heat exchanger. background

[0002] A conventional outdoor unit of an air conditioner is an outdoor unit comprising a box-shaped casing and a heat exchanger disposed within the casing. The heat exchanger and the casing are made of different metals. The metal types for the heat exchanger and the casing are selected according to the required properties. For example, aluminum is generally used for a heat exchanger requiring high thermal conductivity, and iron is generally used for a casing requiring strength.

[0003] In a case where moisture adheres to a contact part between a heat exchanger and a housing, which are dissimilar metals, and in a state where the heat exchanger and the housing are in direct contact with each other, bimetallic corrosion occurs on a metal with a lower self-potential. Hereinafter, bimetallic corrosion is simply referred to as corrosion. As a means of preventing corrosion, it is known to indirectly bond a heat exchanger and a housing using a non-conductive material such as resin.

[0004] However, when such a means is used, the heat exchanger and the case are electrically insulated by the non-conductive material. As a result, a parasitic capacitance is generated between the heat exchanger and the case. Furthermore, such a means has the problem that a voltage change in the parasitic capacitance is caused by electromagnetic noise generated from an electronic substrate, a compressor, and the like arranged in the case, and further electromagnetic noise is generated by the voltage change. Note that an air inlet for introducing outside air is formed in a rear surface of the case, and the heat exchanger is arranged so that the heat exchanger faces the air inlet to perform heat exchange with the outside air.The electromagnetic noise is emitted between the heat exchanger and the housing through the air inlet to the outside.

[0005] To simultaneously solve two problems, namely, preventing corrosion and reducing electromagnetic noise, Patent Literature 1 discloses a technique in which a conductive connecting material is disposed between a heat exchanger and a casing. The connecting material includes a first connecting portion and a second connecting portion. The first connecting portion is made of the same metal type as the metal used in the heat exchanger and is in direct contact with the heat exchanger. The second connecting portion is made of the same metal type as the metal used in the casing and is in direct contact with the casing. Furthermore, an insulating layer is provided between the first connecting portion and the second connecting portion, electrically insulating the first connecting portion from the second connecting portion.

[0006] In the technique disclosed in Patent Literature 1, part of the insulating layer is removed, and the first connecting portion and the second connecting portion, which are made of different metals, are partially brought into direct contact with each other to reduce electromagnetic noise by ensuring electrical conductivity. At the same time, a contact portion between the first and second connecting portions is covered with a covering material such as a waterproof tape to prevent moisture from entering the contact portion and thus prevent metal corrosion.

[0007] Patent Literature 2 discloses a heat exchanger in which an insulating means is provided, by which contact between the heat exchanger made of a first metal and a casing made of a second metal in which the heat exchanger is arranged can be prevented to suppress galvanic corrosion. Citation listPatent literature Patent literature 1: JP 6 583 489 B1; Patent literature 2: US 6,390,180 B1 Overview of the inventionThe problem to be solved by the invention

[0008] However, in the technique disclosed in Patent Literature 1, the use of multiple metals for the connecting material, the provision of the insulating layer, and the use of the waterproof covering material result in structural complexity. Therefore, the technique disclosed in Patent Literature 1 has problems such as an increase in the number of production steps and an increase in the number of parts.

[0009] The present disclosure has been made in view of the above-mentioned embodiment, and an object of the present disclosure is to obtain an outdoor unit of an air conditioner capable of achieving both corrosion prevention and electromagnetic noise reduction with a simple structure. Means of solving the problem

[0010] To solve the above-mentioned problems and achieve the object, an outdoor unit of an air conditioner according to the present disclosure includes: a casing made of a first metal, the casing having a box shape; a heat exchanger disposed in the casing and fixed to the casing via a non-conductive material, at least a part of the heat exchanger being made of a second metal different in self-potential from the first metal; and a conductive material made of a non-metal disposed in the casing. The conductive material is fixed to the casing and electrically connected to the casing, and is electrically connected to the heat exchanger. Effects of the invention

[0011] The outdoor unit of an air conditioner according to the present disclosure has an effect of achieving both corrosion prevention and electromagnetic noise reduction with a simple structure. Short description of the drawings Fig. 1 is an exploded perspective view of an outdoor unit of an air conditioner according to a first embodiment, schematically showing the outdoor unit. Fig. 2 is a front view of the outdoor unit of an air conditioner according to the first embodiment, showing the outdoor unit in a state where a case ceiling member of a case has been removed. Fig. 3 is an exploded perspective view of an electronic substrate box and an interface member in the first embodiment. Fig. Figure 4 is a perspective view of the box for electronic substrates and the interface element shown in Fig. 3, and shows a state in which the electronic substrate box and the interface element have been assembled. Fig. 5 is a right side view of the outdoor unit of an air conditioner in the first embodiment. Fig. 6 is a cross-sectional view of the outdoor unit along the Fig. Line VI-VI shown in Figure 2. Fig. 7 is a perspective view of a heat exchanger in the first embodiment, schematically showing the heat exchanger. Fig. 8 is a front view of the heat exchanger in the first embodiment. Fig. 9 is an enlarged view of a main part of the Fig. 8 shown heat exchanger. Fig. 10 is a plan view of a conductive material in the first embodiment, showing a first conductive material. Fig. 11 is a plan view of the conductive material in the first embodiment, showing a second conductive material. Fig. 12 is a plan view of the outdoor unit of an air conditioner according to the first embodiment, showing a state in which a case ceiling member of the case has been removed and the conductive materials have been attached to the case. Fig. 13 is a schematic diagram showing a transmission path of electromagnetic noise as an electric circuit in the outdoor unit of an air conditioner according to the first embodiment. Fig. 14 is a circuit diagram showing, as an equivalent circuit, a path through which current acting as electromagnetic noise is sent in a case where no conductive material is provided in the outdoor unit of an air conditioner according to the first embodiment. Fig. 15 is a rear view of the outdoor unit of an air conditioner according to the first embodiment, showing the locations where electromagnetic noise is generated when no conductive material is provided. Fig. 16 is a circuit diagram showing, as an equivalent circuit, a path through which current acting as electromagnetic noise is sent in a case where the heat exchanger and the casing in the outdoor unit of an air conditioner according to the first embodiment are brought into direct contact with each other without interposing any insulating material therebetween. Description of the embodiments

[0012] Hereinafter, an outdoor unit of an air conditioner according to an embodiment will be described in detail with reference to the drawings. First embodiment.

[0013] Fig. 1 is an exploded perspective view of an outdoor unit 1 of an air conditioner according to a first embodiment, schematically showing the outdoor unit 1. As shown in Fig. As shown in Figure 1, the outdoor unit 1 of an air conditioner includes a casing 2, a plurality of conductive materials 3, a separator 4, a fan 5, a heat exchanger 6, a plurality of insulating materials 7, a compressor 8, and an electronic substrate box 9. Hereinafter, the outdoor unit 1 of an air conditioner may be simply referred to as the outdoor unit 1.

[0014] In the following description of a direction of each constituent element of the outdoor unit 1, an X-axis direction is defined as the depth direction of the outdoor unit 1, a Y-axis direction as the height direction of the outdoor unit 1, and a Z-axis direction as the width direction of the outdoor unit 1. Furthermore, a positive X-axis direction is defined as the forward direction, and a negative X-axis direction is defined as the backward direction. The positive X-axis direction refers to a direction from the negative side to the positive side of the X-axis. The negative X-axis direction refers to a direction from the positive side to the negative side of the X-axis. Furthermore, a positive Y-axis direction is defined as the upward direction, and a negative Y-axis direction is defined as the downward direction. The positive Y-axis direction refers to a direction from the negative side to the positive side of the Y-axis.The negative Y-axis direction refers to a direction from the positive side to the negative side of the Y-axis. Furthermore, a positive Z-axis direction is defined as a rightward direction, and a negative Z-axis direction is defined as a leftward direction. The positive Z-axis direction refers to a direction from the negative side to the positive side of the Z-axis. The negative Z-axis direction refers to a direction from the positive side to the negative side of the Z-axis. In the first embodiment, the positive side of the X-axis direction to which an airflow generated by the fan 5 in the outdoor unit 1 is externally discharged is regarded as the front side, and the side opposite the front side is regarded as the rear side.

[0015] Fig. Fig. 2 is a front view of the outdoor unit 1 of an air conditioner according to the first embodiment, showing the outdoor unit 1 in a state in which a front case member 2e of the case 2 has been removed. In Fig. 2, the heat exchanger 6 is shaded by dots for better understanding. As shown in the Fig. 1 and Fig. As shown in Figure 2, the housing 2 is a box-shaped object that functions as the outer shell of the outdoor unit 1. The housing 2 is made of a first metal. The first metal is preferably a high-strength metal. The first metal is, for example, iron or an iron alloy.

[0016] As in Fig. 1, the housing 2 comprises a housing bottom element 2a, a housing top element 2b, a first coupling element 2c, and a second coupling element 2d. The housing bottom element 2a forms a bottom of the outer shell of the outdoor unit 1. The shape of the housing bottom element 2a is a rectangle with four rounded corners in plan view. The housing top element 2b is arranged above the housing bottom element 2a and away from the housing bottom element 2a. The housing top element 2b forms a ceiling surface of the outer shell of the outdoor unit 1. The shape of the housing top element 2b in plan view is the same as the shape of the housing bottom element 2a.

[0017] The first coupling element 2c and the second coupling element 2d couple the housing bottom element 2a to the housing top element 2b. The first coupling element 2c has an L-shape in plan view. The first coupling element 2c includes: the housing front element 2e, which extends along the Z-axis direction; and a housing side element 2f, which extends rearward from a left edge of the housing front element 2e. The left edge is one of the edges of the housing front element 2e in the Z-axis direction.

[0018] The housing front member 2e couples a front edge of the housing bottom member 2a to a front edge of the housing top member 2b. The housing front member 2e forms a front surface of the outer shell of the outdoor unit 1. An air outlet 2j is formed in the housing front member 2e. The air outlet 2j is an opening for discharging an airflow generated by the fan 5 to the outside of a blower chamber 10 described below. The housing side member 2f couples a left edge of the housing bottom member 2a to a left edge of the housing top member 2b. The housing side member 2f forms a left side surface of the outer shell of the outdoor unit 1. The housing front member 2e and the housing side member 2f are integrally formed in the first embodiment, but may be formed separately.

[0019] The second coupling element 2d has an L-shape in plan view. The second coupling element 2d includes: a housing side element 2g extending along the X-axis direction; and a housing rear element 2h extending to the left from a rear edge of the housing side element 2g. The rear edge is one of the edges of the housing side element 2g in the X-axis direction.

[0020] The housing side member 2g couples a right edge of the housing bottom member 2a to a right edge of the housing top member 2b. The housing side member 2g forms a right side surface of the outer shell of the outdoor unit 1. The housing back member 2h couples a part of a rear edge of the housing bottom member 2a to a part of a rear edge of the housing top member 2b. The housing back member 2h forms a part of a rear surface of the outer shell of the outdoor unit 1. The housing side member 2g and the housing back member 2h are integrally formed in the first embodiment, but may be formed separately.

[0021] In a state where the Fig. 1 are assembled, a left edge of the housing rear member 2h and a rear edge of the housing side member 2f are separated from each other. An air inlet 2i for admitting outside air is formed between the left edge of the housing rear member 2h and the rear edge of the housing side member 2f. The air inlet 2i is an opening through which air can flow from outside the housing 2 and into a blower chamber 10, which will be described below. The air inlet 2i is surrounded by the housing bottom member 2a, the housing ceiling member 2b, the housing rear member 2h, and the housing side member 2f.

[0022] The conductive materials 3 are materials to be arranged in the casing 2. The conductive materials 3 are made of non-metal with conductivity instead of a metal. The material of the conductive materials 3 is, for example, a composite material in which a conductor such as carbon fiber is kneaded into insulating plastic, or a composite material in which a thin film of a conductor is formed on the surface of insulating plastic. Examples of such a composite material are carbon graphite. The conductive materials 3 are attached to the casing 2 and electrically connected to the casing 2 and are electrically connected to the heat exchanger 6. The casing 2 and the heat exchanger 6 are electrically connected via the conductive materials 3.In this specification, the term "electrical connection" between a metal material and each conductive material 3 refers not only to a state where the metal material and each conductive material 3 are in direct contact with each other and electrically connected, but also to a state where the metal material and each conductive material 3 are electrically connected through a gap. In the first embodiment, the conductive materials 3 are in contact with the housing 2 and the heat exchanger 6.

[0023] The casing 2 and each conductive material 3 are connected at a contact portion between the casing 2 and the conductive material 3 by welding, a screw, or the like. In a case where the surface of each element of the casing 2 is coated, for example, and the electrical resistance of the surface of each element is high, the electrical resistance of the surface of each element only needs to be reduced, for example, by partially or completely covering the connection portion in advance or peeling off the coating when screwing each conductive material 3 to the casing 2 using a locking screw. The outdoor unit 1 may include a single conductive material 3 or a plurality of conductive materials 3. In the first embodiment, the outdoor unit 1 includes two conductive materials 3.Hereinafter, in a case where the two conductive materials 3 are different from each other, one of the conductive materials 3 is referred to as the first conductive material 3a and the other conductive material 3 is referred to as the second conductive material 3b.

[0024] As in Fig. As shown in Figure 2, the partition member 4 is a metal material that divides the interior of the housing 2 into the blower chamber 10 and an electrical chamber 11. The partition member 4 functions as a part of the housing 2. The blower chamber 10 and the electrical chamber 11 are formed adjacent to each other in the Z-axis direction. The partition member 4 extends in the Y-axis direction from the housing bottom member 2a to the electronic substrate box 9. The partition member 4 extends in the X-axis direction from the housing front member 2e to the housing rear member 2h, as shown in Figure 2. Fig. 1 shown.

[0025] The housing 2 and the separating element 4, which are Fig. 1 are made of the same first metal. The housing 2 and the separator 4 are connected at a contact portion between the housing 2 and the separator 4 by welding, a screw, or the like. For example, when the surface of each member of the housing 2 is coated and the electrical resistance of the surface of each member is high, the electrical resistance of the surface of each member only needs to be reduced, for example, by partially or completely covering the connection portion in advance or peeling off the coating at the time of screwing the separator 4 to the housing 2 using a locking screw.

[0026] As in Fig. 2, the fan 5 is a device that is arranged in the fan chamber 10 and generates an airflow. The fan 5 includes: a bracket 5a that rises from the housing bottom member 2a; a fan motor 5b attached to the bracket 5a; and a propeller fan 5c that is attached to a rotating shaft of the fan motor 5b and rotates when the fan motor 5b rotates. An upper end portion of the bracket 5a is fixed to the housing ceiling member 2b. A lower end portion of the bracket 5a is fixed to the housing bottom member 2a. The fan motor 5b is electrically connected to an electronic substrate 9c via a fan drive wire 12, which will be described below. The fan motor 5b rotates when it receives a drive signal from the electronic substrate 9c via the fan drive wire 12. When the blower motor 5b rotates to drive the propeller fan 5c, a negative pressure is generated in the blower chamber 10.As a result, air flows from outside the outdoor unit 1 through the air inlet 2i into the blower chamber 10. The air flowing into the blower chamber 10 passes through the heat exchanger 6, is converted into an air stream by the fan 5, and is discharged from the in . Fig. 1 shown air outlet 2j from the blower chamber 10 to the outside.

[0027] The heat exchanger 6 is an object arranged in the blower chamber 10 that performs heat exchange between a refrigerant and outside air. The outside air, which is introduced into the blower 5, flows through the heat exchanger 6. The heat exchanger 6 is, for example, a parallel-flow heat exchanger. The heat exchanger 6 is arranged in the housing 2 and fixed to the housing 2 via the insulating materials 7, which are non-conductive materials. At least a part of the heat exchanger 6 is made of a second metal that differs from the first metal in terms of its self-potential. The second metal is preferably a metal with high thermal conductivity. The second metal is, for example, aluminum or an aluminum alloy. The self-potential of the first metal is higher than the self-potential of the second metal.

[0028] As in Fig. 1, the heat exchanger 6 has an L-shape in plan view. The heat exchanger 6 includes: a first heat exchange unit 6a extending along the Z-axis direction; and a second heat exchange unit 6b extending along the X-axis direction. The second heat exchange unit 6b extends forward from a left edge of the first heat exchange unit 6a. The left edge is one of the edges of the first heat exchange unit 6a in the Z-axis direction. The first heat exchange unit 6a is arranged behind the fan 5. The second heat exchange unit 6b is arranged on the left side of the fan 5 as viewed from the front of the outdoor unit 1. The heat exchanger 6 and the fan 5 are arranged at a distance from each other and are electrically insulated or arranged via an insulating material (not shown) to be electrically insulated.

[0029] The heat exchanger 6 is arranged at a distance from the first coupling element 2c and the second coupling element 2d and is electrically insulated therefrom or arranged via an insulating material (not shown) to be electrically insulated. As shown in Fig. As shown in Figure 2, an upper end portion of the heat exchanger 6 is fixed to the housing ceiling member 2b via the insulating material 7. A lower end portion of the heat exchanger 6 is fixed to the housing bottom member 2a via the insulating material 7. The heat exchanger 6 is electrically insulated from the housing ceiling member 2b and the housing bottom member 2a. The heat exchanger 6 is arranged so that the heat exchanger 6 does not come into direct contact with metal objects such as the housing 2 and the fan 5, which are arranged around the heat exchanger 6.

[0030] As material for the two in Fig. 1, a material having electrical insulating properties, such as resin, is used. Hereinafter, when the two insulating materials 7 are different from each other, the insulating material 7 provided at the lower end portion of the heat exchanger 6 is referred to as the first insulating material 7a, and the insulating material 7 provided at the upper end portion of the heat exchanger 6 is referred to as the second insulating material 7b. In the first embodiment, the first insulating material 7a and the second insulating material 7b, which have the same shape and size as the heat exchanger 6 in plan view, are used to cover the entire lower and upper surfaces of the heat exchanger 6 to electrically insulate the heat exchanger 6 from the case 2. However, this configuration is not intended to limit the means for electrically insulating the two materials.For example, a plurality of blocks made of a material with electrical insulating properties can be provided at the bottom of the heat exchanger 6 such that the plurality of blocks are arranged between the heat exchanger 6 and the housing bottom member 2a. With such a configuration, the heat exchanger 6 and the housing bottom member 2a are separated from each other in the Y-axis direction. Thus, the heat exchanger 6 and the housing bottom member 2a can be electrically insulated from each other.

[0031] As in Fig. As shown in Figure 2, the compressor 8 is a device disposed in the electrical chamber 11 and compresses the refrigerant flowing in the heat exchanger 6. The compressor 8 is disposed on the housing bottom member 2a in a lower space in the electrical chamber 11. The compressor 8 is fixed to the housing bottom member 2a with a screw or the like.

[0032] The electronic substrate box 9 is an object that houses the electronic substrate 9c, such as a control board, required for the operation of the outdoor unit 1. The electronic substrate box 9 has the shape of a hollow rectangular parallelepiped. The electronic substrate box 9 is fixed to an upper end portion of the partition member 4 and disposed above the blower chamber 10 and the electrical chamber 11. A downwardly extending heat sink 9d is fixed to a part of the electronic substrate box 9 disposed in the blower chamber 10. The heat sink 9d is exposed in the blower chamber 10. The heat sink 9d is cooled by an airflow generated by the fan 5.

[0033] A portion of the electronic substrate box 9, located in the electrical chamber 11, is arranged above the compressor 8. The compressor drive wires 13 are connected to a portion of the electronic substrate 9c located in the electrical chamber 11. The compressor 8 is electrically connected to the electronic substrate 9c via the compressor drive wires 13. The compressor 8 is driven when it receives a drive signal output from the electronic substrate 9c via the compressor drive wires 13.

[0034] The electrical chamber 11 is surrounded by the housing bottom member 2a, the separating member 4, the housing side member 2g, the box 9 for electronic substrates and the housing front member 2e and the housing rear member 2h, as shown in Fig. 1. The electrical compartment 11 has a waterproof structure capable of preventing the intrusion of moisture such as rainwater from outside the casing 2. A shut-off valve 17 is provided on a lower part of an outer surface of the casing side member 2g. The shut-off valve 17 functions as a connection port for refrigerant piping connected to an indoor unit (not shown).

[0035] The compressor 8 and the shut-off valve 17 are connected to each other via a plurality of refrigerant lines 18. The compressor 8 and the heat exchanger 6 are connected to each other via a plurality of refrigerant lines 18. Connecting portions 19 for connecting the heat exchanger 6 and the refrigerant lines 18 are arranged in the electrical chamber 11 having the waterproof structure. When the connecting portions 19 are arranged in the electrical chamber 11 as described above, contact between the connecting portions 19 and moisture can be prevented. Thus, corrosion of the connecting portions 19 can be prevented. Note that to further improve the waterproofing effect for the connecting portions 19, waterproof tape or the like may be wound around the connecting portions 19 to achieve waterproofing.Although not specifically shown, valve devices such as a four-way valve and an expansion valve are connected to the refrigerant lines 18. The four-way valve switches the refrigerant flow directions. The expansion valve expands the refrigerant to a predetermined pressure. The connection shape of the refrigerant lines 18 is not limited to that shown in the drawing.

[0036] An interface element 20 is installed in an upper space in the electrical chamber 11. The interface element 20 is fixed to an inner surface of the case side member 2g and a lower surface of the electronic substrate box 9. A terminal block 21 is installed on the interface element 20. External AC power lines 14 and internal power lines 15 are connected to the terminal block 21. The external AC power lines 14 are electrically connected to the internal power lines 15 via the terminal block 21. The internal power lines 15 are electrically connected to the electronic substrate 9c. The electronic substrate 9c is supplied with electrical power via the external AC power lines 14, the terminal block 21, and the internal power lines 15.The voltage of the electric power to be applied to the electronic substrate 9c is, for example, a single-phase voltage of 200 V, but is not limited to this voltage.

[0037] The interface element 20 is made of the same metal as the housing side element 2g. Therefore, the interface element 20 is connected to the housing side element 2g with low electrical resistance. The interface element 20 is connected to a signal ground of the electronic substrate 9c. The interface element 20 has a ground connection point 20e to which a ground wire 16 is connected. The interface element 20 is grounded via the ground connection point 20e and the ground wire 16. The housing 2 connected to the interface element 20 and the separator 4 connected to the housing 2 are grounded via the ground connection point 20e and the ground wire 16.

[0038] Next, the configuration of the outdoor unit 1 will be described in more detail. First, the configurations of the electronic substrate box 9 and the interface element 20 will be described with reference to Fig. 3 and Fig. 4 described. Fig. 3 is an exploded perspective view of the electronic substrate box 9 and the interface member 20 in the first embodiment. Fig. Figure 4 is a perspective view of the box 9 for electronic substrates and the interface element 20 shown in Fig. 3, which shows a state in which the electronic substrate box 9 and the interface element 20 have been assembled.

[0039] As in Fig. 3, the electronic substrate box 9 includes: a lower box 9a, which is box-shaped and opens upward; an upper cover 9b, which covers an upper opening of the lower box 9a; and the heat sink 9d. The electronic substrate 9c is arranged in the lower box 9a and fixed to the lower box 9a. The electronic substrate 9c includes: the internal power lines 15 connected to the terminal block 21; and the compressor drive wires 13 connected to the compressor 8. Although not shown, the electronic substrate 9c includes various power lines and the like for driving a heater, the fan motor 5b, and other driving devices.

[0040] The heat sink 9d is attached to the electronic substrate 9c in such a way that it is in close contact with the electronic substrate 9c. The heat sink 9d serves to cool the heating element of the electronic substrate 9c. The heating element is, for example, a power semiconductor characterized by an insulated gate bipolar transistor (IGBT). The electronic substrate 9c, to which the heat sink 9d is attached, is inserted into the lower box 9a from the upper opening of the lower box 9a. As shown in the Fig. 3 and Fig. 4, the heat sink 9d is partially or completely exposed to the outside of the lower box 9a through a hole 9e formed in a bottom wall of the lower box 9a.

[0041] The Fig. The lower box 9a and the upper cover 9b shown in FIG. 3 are made of, for example, rubber, resin, metal such as iron, or a combination thereof. For example, when the lower box 9a and the upper cover 9b are made of metal, the electronic substrate box 9 has a structure such that the periphery of the electronic substrate 9c is covered with metal. This makes it possible to suppress the emission of electromagnetic noise generated by the electronic substrate 9c outside the electronic substrate box 9. There is a possibility that moisture such as rainwater splashing into the blower chamber 10 penetrates into the electronic substrate box 9c and the electrical chamber 11 through the hole 9e in the bottom wall of the lower box 9a.Therefore, in practice, measures such as developing better shapes of the hole 9e and the lower box 9a so that moisture cannot easily penetrate, or adding a new sealing structure are taken to ensure the waterproofness of the inside of the electronic substrate box 9 and the electrical chamber 11.

[0042] The interface element 20 includes a vertical interface wall 20a, an upper connecting flange portion 20b, a transverse interface wall 20c, and a lower connecting flange portion 20d. The vertical interface wall 20a is a vertical wall extending along the Y-axis direction. The upper connecting flange portion 20b extends horizontally in the Z-axis direction from an upper edge of the vertical interface wall 20a. The upper connecting flange portion 20b is connected to the lower surface of the bottom wall of the lower box 9a. The transverse interface wall 20c extends horizontally in the Z-axis direction from a lower edge of the vertical interface wall 20a. The lower connecting flange portion 20d extends downward in the Y-axis direction from a front edge of the transverse interface wall 20c.The lower connecting flange portion 20d is connected to the inner surface of the housing side member 2g shown in . Fig. 2. The lower connecting flange portion 20d of the interface element 20 is fixed to the housing side element 2g and electrically connected to the housing side element 2g. The interface element 20 is fixed to each housing side element 2g and the lower box 9a.

[0043] Next, the configuration of a right side surface of the outdoor unit 1 will be described with reference to Fig. 5 described. Fig. 5 is a right side view of the outdoor unit 1 of an air conditioner in the first embodiment.

[0044] An opening 2k is formed in the housing side member 2g. Through the opening 2k, the inside and outside of the housing 2 can communicate directly with each other. An interface cover 22 is detachably attached to the housing side member 2g. The interface cover 22 opens and covers the opening 2k by detaching and attaching. When attached, the interface cover 22 covers the opening 2k; and when detached, the interface cover 22 opens the opening 2k. The interface element 20 and the terminal block 21 installed in the electrical chamber 11 can be visually recognized and handled through the opening 2k. It is possible to perform the work of connecting various power lines through the opening 2k by detaching the interface cover 22 from the housing side member 2g.

[0045] The interface cover 22 serves to prevent moisture such as rainwater from entering the electrical chamber 11 while ensuring air permeability between the electrical chamber 11 and the outside of the housing 2. The interface cover 22 is made of resin, metal such as iron, or a combination thereof. In a case where the interface cover 22 is made of metal such as iron and is bonded to the housing side member 2g with low electrical resistance, it is possible to suppress the emission of electromagnetic noise from the opening 2k to the outside of the housing 2 by covering the opening 2k with the interface cover 22.

[0046] Although not shown, a hole is formed in the interface cover 22 to ensure ventilation between the electrical chamber 11 and the outside of the casing 2, and to insert and remove a power line from the outside of the casing 2 into and from the electrical chamber 11. Waterproofing measures are taken for the hole to prevent moisture such as rainwater from entering the electrical chamber 11. Examples of waterproofing measures include inserting a sponge into a gap between the power line and the inner surface of the hole or forming the hole with a louvered structure.

[0047] Next, the configuration of the separating element 4 will be described with reference to Fig. 6 described. Fig. 6 is a cross-sectional view of the outdoor unit 1 along the Fig. 2 shown line VI-VI. In Fig. 6 only the housing 2 is hatched for better understanding.

[0048] The separator 4 includes a first partition 4a and a second partition 4b extending from a rear edge of the first partition 4a. An insertion hole 4c is formed in the second partition 4b for inserting one end of the heat exchanger 6 in the Z-axis direction into the electrical chamber 11. The heat exchanger 6 and the second partition 4b are made of different metals. For example, a resin material is preferably interposed between the heat exchanger 6 and the second partition 4b to prevent contact between different metals.

[0049] Next, the configuration of the heat exchanger 6 is described with reference to the Fig. 7 to 9 are described in more detail. Fig. 7 is a perspective view of the heat exchanger 6 in the first embodiment, schematically showing the heat exchanger 6. Fig. Fig. 8 is a front view of the heat exchanger 6 in the first embodiment. Fig. 9 is an enlarged view of a main part of the Fig. 8 shown heat exchanger 6.

[0050] As in Fig. 7, the heat exchanger 6 in the first embodiment is a parallel flow heat exchanger. As shown in Fig. 8, the heat exchanger 6 comprises two pipe manifolds 6c and 6d, a plurality of refrigerant pipes 6e and a plurality of fins 6f.

[0051] The two line distributors 6c and 6d are both hollow metal objects. Each of the line distributors 6c and 6d extends along the Y-axis direction. As shown in Fig. As shown in Figure 7, the two manifolds 6c and 6d are spaced apart from each other in the Z-axis direction and arranged so as to be offset from each other in the X-axis direction. The manifold 6c is provided at a front edge of the second heat exchanger unit 6b. The manifold 6d is provided at a right edge of the first heat exchanger unit 6a. The refrigerant lines 18 are connected to the manifold 6d.

[0052] Each of the Fig. The refrigerant pipes 6e shown in Figure 8 are hollow metal objects. Each refrigerant pipe 6e is, for example, a flat pipe with a flat shape. The plurality of refrigerant pipes 6e are arranged at a distance from each other in the Y-axis direction. Each of the refrigerant pipes 6e extends from one of the pipe manifolds 6c to the other pipe manifold 6d. The direction in which each refrigerant pipe 6e extends is orthogonal to the Y-axis direction. One end of each refrigerant pipe 6e in the extending direction is connected to one of the pipe manifolds 6c, and the other end of each refrigerant pipe 6e in the extending direction is connected to the other pipe manifold 6d. Each refrigerant pipe 6e enables communication between one of the pipe manifolds 6c and the other pipe manifold 6d.

[0053] The fins 6f are plate-like objects made of metal. Each fin 6f is arranged between adjacent refrigerant lines 6e. The shape of each fin 6f is not particularly limited, but in the first embodiment, it is wave-shaped and protrudes alternately upward and downward. That is, the fins 6f are corrugated fins in the first embodiment. As shown in Fig. 9, each fin 6f is in contact with each of the adjacent refrigerant pipes 6e and is connected thereto by welding or the like.

[0054] The refrigerant flows into the Fig. 8 and in the refrigerant lines 6e. One of the two line distributors 6c and 6d serves to distribute the refrigerant to each of the plurality of refrigerant lines 6e. The other of the two line distributors 6c and 6d serves to converge the refrigerant flowing out of each of the plurality of refrigerant lines 6e. The refrigerant lines 6e serve to perform heat exchange between the refrigerant and the outside air. That is, the heat exchange occurs between the refrigerant flowing in the refrigerant lines 6e and the outside air flowing around the refrigerant lines 6e. The fins 6f serve to promote heat exchange between the refrigerant and the outside air.

[0055] Next, the configurations of the conductive materials 3 are described with reference to the Fig. 10 and Fig. 11 described in more detail. Fig. 10 is a plan view of the conductive material 3 in the first embodiment, showing the first conductive material 3a. Fig. 11 is a plan view of the conductive material 3 in the first embodiment, showing the second conductive material 3b. Fig. 12 is a plan view of the outdoor unit 1 of an air conditioner according to the first embodiment, showing a state in which the case ceiling member 2b of the case 2 has been removed and the conductive materials 3 have been attached to the case 2. Fig. 12 shows the heat exchanger 6 in direct contact with the separating member 4, the casing side member 2f and the like of the casing 2. In fact, however, the heat exchanger 6 is arranged so that the heat exchanger 6 does not come into direct contact with a metal object such as the casing 2. In Fig. 12, the heat exchanger 6 is shaded by dots for better understanding.

[0056] As in Fig. As shown in Figure 10, the shape of the first conductive material 3a is not particularly limited, but in the first embodiment, it is an L-shape. The first conductive material 3a includes a first plate portion 3c and a second plate portion 3d. Fig. The first conductive material 3a shown in Figure 12 electrically connects the separator 4 and the first heat exchanger unit 6a. The first conductive material 3a is arranged in the blower chamber 10. The first conductive material 3a is arranged at an inner corner formed by the separator 4 and the first heat exchanger unit 6a. The first conductive material 3a is arranged on the left side of the separator 4. The first conductive material 3a is arranged in front of the first heat exchanger unit 6a. The first conductive material 3a is attached to the separator 4, which is part of the housing 2, and electrically connected to the separator 4 and electrically connected to the first heat exchanger unit 6a.

[0057] The first plate part 3c extends along the X-axis direction. The first plate part 3c is in contact with a side surface 4d of the partition member 4 facing the blower chamber 10. The side surface 4d is a plane extending in the X-axis direction and the Y-axis direction. The first plate part 3c is fixed to the partition member 4. The second plate part 3d extends along the Z-axis direction. The second plate part 3d extends from a rear edge of the first plate part 3c to the left. The rear edge is one of the edges of the first plate part 3c in the Z-axis direction. The second plate part 3d is in contact with a front surface 6g of the first heat exchanger unit 6a facing the blower chamber 10. The front surface 6g is a plane extending in the Z-axis direction and the Y-axis direction.

[0058] As in Fig. As shown in Figure 11, the shape of the second conductive material 3b is not particularly limited, but in the first embodiment, it is a crank shape. The second conductive material 3b includes a fixed part 3e, a plate part 3f, and a coupling part 3g that couples the fixed part 3e to the plate part 3f. Fig. The second conductive material 3b shown in Figure 12 electrically connects the casing side panel 2f and the second heat exchanger unit 6b. The second conductive material 3b is disposed in the blower chamber 10. The second conductive material 3b is disposed at an inner corner formed by the casing side panel 2f and the second heat exchanger unit 6b. The second conductive material 3b is disposed on the right side of the casing side panel 2f. The second conductive material 3b is disposed in front of the second heat exchanger unit 6b and extends to the left. The second conductive material 3b is fixed to the casing side panel 2f and electrically connected to the casing side panel 2f and is electrically connected to the second heat exchanger unit 6b.

[0059] The fixed part 3e extends along the X-axis direction. The fixed part 3e is in contact with an inner surface 2m of the casing side member 2f, which faces the blower chamber 10. The inner surface 2m is a plane extending in the X-axis direction and the Y-axis direction. The fixed part 3e is fixed to the casing side member 2f. The coupling part 3g extends from a rear edge of the fixed part 3e to the right. The rear edge is one of the edges of the fixed part 3e in the X-axis direction. The coupling part 3g extends along the Z-axis direction. The coupling part 3g is in contact with a front surface 6h of the second heat exchanger unit 6b, which faces the blower chamber 10. The front surface 6h is a plane extending in the Z-axis and Y-axis directions. The plate portion 3f extends rearward from a right edge of the coupling portion 3g.The right edge is one of the edges of the coupling part 3g in the Z-axis direction. The plate part 3f extends in the X-axis direction. The plate part 3f is in contact with a side surface 6i of the second heat exchanger unit 6b facing the blower chamber 10. The side surface 6i is a plane extending in the X-axis direction and the Y-axis direction. The side surface 6i extends from a right edge of the front surface 6h rearward to the front surface 6g. The right edge is one of the edges of the front surface 6h in the Z-axis direction.

[0060] In the first embodiment, the conductive materials 3 are attached to the case side member 2f or the partition member 4 to be electrically connected to the case 2. However, the conductive materials 3 only need to be attached to the case bottom member 2a, case top member 2b, case front member 2e, case rear member 2h, case side members 2f and 2g, and / or partition member 4 to establish electrical connection with the case 2. The size of each conductive material 3 is preferably determined so that the electrical connection between the case 2 and the heat exchanger 6 can be maintained without being affected even by vibrations or the like while the outdoor unit 1 is in operation.

[0061] Next, operation and effects of the outdoor unit 1 according to the first embodiment will be described.

[0062] As in Fig. 2, the electronic substrate 9c enters a standby state when power is supplied from the external AC power lines 14 to the electronic substrate 9c via the internal power lines 15. When the electronic substrate 9c receives an operation start command signal from the indoor unit (not shown) via a communication signal line between the indoor unit and the outdoor unit 1, the electronic substrate 9c causes the outdoor unit 1 to start operation. Specifically, the electronic substrate 9c outputs a drive signal to the fan motor 5b via the fan drive wire 12 to drive the fan motor 5b. Further, the electronic substrate 9c outputs another drive signal to the compressor 8 via the compressor drive wires 13 to drive the compressor 8.At this time, rectangular pulses generated by switching a power semiconductor are generally used as drive signals output from the electronic substrate 9c. Therefore, the drive signals include high-frequency components not originally required for driving AC motors of the compressor 8 and the fan motor 5b, such as switching noise of the power semiconductor and harmonic components of the rectangular pulses. Such high-frequency components become sources of electromagnetic noise and a cause of electromagnetic noise being emitted from the housing 2 to the outside via a transmission path described below.

[0063] Fig. Fig. 13 is a schematic diagram showing the transmission path of electromagnetic noise as an electrical circuit in the outdoor unit 1 of an air conditioner according to the first embodiment. Fig. 13, the heat exchanger 6 is shaded by dots for clarity. For example, when a three-phase motor is used as the AC motor of the compressor 8, the electromagnetic noise generated in the electronic substrate 9c is transmitted to a casing of the compressor 8 via a neutral point 8d of the three-phase motor winding through a parasitic capacitance 8b existing between a motor winding 8a and the casing of the compressor 8. Part of the electromagnetic noise transmitted to the casing of the compressor 8 is transmitted to the casing bottom member 2a and then returned to the electronic substrate 9c. However, since there are impedance components such as a contact resistance 8c between the casing of the compressor 8 and the casing bottom member 2a, part of the electromagnetic noise transmitted to the casing of the compressor 8 is transmitted to the heat exchanger 6 via the refrigerant lines 18.

[0064] The characteristics of the parasitic impedance components of the heat exchanger 6 vary depending on the structure of the heat exchanger 6. Here, it is assumed that the heat exchanger 6 is a parallel flow heat exchanger comprising the fins 6f and the refrigerant pipes 6e having a flat shape as shown in Fig. 8, and an equivalent circuit is shown in which parasitic inductances 23 included in the heat exchanger 6 are arranged as shown in Fig. 13, as an example. The parasitic impedance components, such as the parasitic inductances 23 included in the heat exchanger 6, are complicated as a distributed constant circuit, as shown in Fig. 13. Since the heat exchanger 6 and the housing 2 are electrically insulated by the first insulating material 7a and the second insulating material 7b, parasitic capacitances 22a and 22b are generated between the heat exchanger 6 and the housing 2. That is, the parasitic capacitance 22a is generated between the heat exchanger 6 and the housing bottom member 2a, and the parasitic capacitance 22b is generated between the heat exchanger 6 and the housing top member 2b. The parasitic capacitances 22a and 22b are generated on the transmission path of the electromagnetic noise.

[0065] Fig. 14 is a circuit diagram showing, as an equivalent circuit, a path through which current acting as electromagnetic noise is transmitted in a case where no conductive material 3 is provided in the outdoor unit 1 of an air conditioner according to the first embodiment. Electromagnetic noise transmitted from the electronic substrate 9c to the heat exchanger 6 and the housing 2 as shown in Fig. 13, transmitted through the compressor 8, generates: resonance with the parasitic inductances 23 included in the heat exchanger 6; resonance with the parasitic capacitances 22a and 22b; and resonance with a parasitic impedance component such as a parasitic inductance 24 of each element of the housing 2. At this time, a voltage change occurs in the parasitic capacitances 22a and 22b due to the resonance.

[0066] In Fig. 15 is a rear view of the outdoor unit 1 of an air conditioner according to the first embodiment, showing locations where electromagnetic noise is generated when no conductive material 3 is present. In Fig. 15, the heat exchanger 6 is shaded by dots for clarity. Gaps G1, G2, G3, and G4 are formed between the heat exchanger 6 and the elements of the housing 2 to ensure electrical insulation. Fig. 15, the positions of columns G1, G2, G3 and G4 are surrounded by dashed lines. In Fig. 15 is shown as if the gaps G1, G2, G3, and G4 were not present in a part of a space between the heat exchanger 6 and the casing 2, but in fact, the gaps G1, G2, G3, and G4 are present, which are elongated and extend so as to surround four sides of the heat exchanger 6. The gaps G1, G2, G3, and G4 correspond to the locations where electromagnetic noise is generated when the outdoor unit 1 does not include a conductive material 3. Voltage changes occur between the heat exchanger 6 and the casing bottom member 2a and between the heat exchanger 6 and the casing top member 2b due to the parasitic capacitances 22a and 22b, respectively, which are in Fig. 13. As a result, the gaps G1, G2, G3, and G4 function as slot antennas and further generate electromagnetic noise according to the changes in the voltages applied to both ends of the gaps G1, G2, G3, and G4. The electromagnetic noise generated in the gaps G1, G2, G3, and G4 is emitted to the outside of the casing 2 through the air inlet 2i when the outdoor unit 1 does not have a conductive material 3.

[0067] Fig. 16 is a circuit diagram showing, as an equivalent circuit, a path through which current acting as electromagnetic noise is transmitted in a case where the heat exchanger 6 and the casing 2 are brought into direct contact with each other without interposing the insulating material 7 in the outdoor unit 1 of an air conditioner according to the first embodiment. Due to the removal of the first insulating material 7a and the second insulating material 7b, as shown in Fig. As shown in Figure 15, the heat exchanger 6 and each element of the housing 2 are electrically connected. That is, the heat exchanger 6 and each element of the housing 2 are electrically short-circuited. Therefore, as shown in Figure 16, the parasitic capacitances 22a and 22b generated between the heat exchanger 6 and the elements of the housing 2 are short-circuited. Consequently, no voltage change occurs between the heat exchanger 6 and the housing bottom element 2a and between the heat exchanger 6 and the housing top element 2b, as shown in Figure 16. Fig. 15, by the parasitic capacitances 22a and 22b, as shown in Fig. 16, and no electromagnetic noise is generated in the columns G1, G2, G3 and G4.

[0068] In a case where the heat exchanger 6 and the housing 2, as in Fig. 15, are made of different metals, and no insulating material 7 is provided between the heat exchanger 6 and the casing 2, the generation of electromagnetic noise in the gaps G1, G2, G3, and G4 can be prevented to reduce the emission of electromagnetic noise to the outside of the casing 2, but corrosion occurs in the heat exchanger 6 having a low self-potential at a contact portion between the heat exchanger 6 and the casing 2. However, when insulating materials 7 are provided between the heat exchanger 6 and the casing 2, the corrosion of the heat exchanger 6 having a low self-potential at the contact portion between the heat exchanger 6 and the casing can be prevented, but electromagnetic noise is generated in the gaps G1, G2, G3, and G4, so that an amount of electromagnetic noise emitted to the outside of the casing 2 increases.

[0069] As in Fig. 12, the outdoor unit 1 of the first embodiment includes: the casing 2, which has a box shape and is made of the first metal; the heat exchanger 6, which is made of the second metal, having a self-potential different from that of the first metal, arranged in the casing 2 and fixed to the casing 2 via the insulating materials 7; and the conductive materials 3 made of non-metal arranged in the casing 2. The conductive materials 3 are fixed to the casing 2 and electrically connected to the casing 2 and are electrically connected to the heat exchanger 6. In these configurations, the heat exchanger 6 and the casing 2 are electrically connected via the conductive materials 3. Therefore, the parasitic capacitances 22a and 22b existing between the heat exchanger 6 and the Fig. 13 shown elements of the housing 2 are short-circuited. As a result, voltage changes to be generated by the parasitic capacitances 22a and 22b between the heat exchanger 6 and the housing 2 are suppressed so that electromagnetic noise generated by the elements shown in Fig. 15 shown columns G1, G2, G3 and G4 is suppressed.

[0070] In the first embodiment, the heat exchanger 6 and the housing 2 are not in direct contact with each other, as in Fig. 12. This makes it possible to prevent corrosion due to contact between the heat exchanger 6 and the casing 2. Furthermore, since the conductive materials 3 in the first embodiment are made of a non-metal, it is possible to prevent the occurrence of corrosion due to contact between the casing 2 and the conductive materials 3, as well as the occurrence of corrosion due to contact between the heat exchanger 6 and the conductive materials 3. That is, it is possible to both prevent corrosion and reduce electromagnetic noise with a simple structure in which the outdoor unit 1 includes the conductive materials 3.

[0071] In the first embodiment, the conductive materials 3 are attached to and electrically connected to the case side member 2f and the separator 4, as shown in Fig. 12. Meanwhile, the conductive materials 3 can be applied to all the housing base elements 2a, the housing cover elements 2b, the housing front elements 2e, the housing rear elements 2h, the housing side elements 2f and 2g and the Fig. 1. In a case where the conductive materials 3 are configured in this way, the electrical connection between the plates is strengthened. This allows the contact resistance and the parasitic inductances 23 of the Fig. 13 can be reduced. Therefore, it is possible to reduce the electromagnetic noise transmitted to the electronic substrate 9c, the compressor 8, and each element of the package 2. That is, it is possible to reduce the noise terminal voltage, the noise power intensity, and the like.

[0072] In the first embodiment, the self-potential of the first metal is higher than the self-potential of the second metal. Therefore, corrosion occurs in the heat exchanger 6 made of the second metal when the heat exchanger 6 and the housing 2 are brought into direct contact with each other. In this regard, the heat exchanger 6 and the housing 2 are not in direct contact with each other in the first embodiment, as described above. Therefore, corrosion of the heat exchanger 6 can be prevented.

[0073] In the first embodiment, since the first metal is iron or an iron alloy, the strength of the housing 2 made of the first metal can be increased. Furthermore, since the second metal in the first embodiment is aluminum or an aluminum alloy, the thermal conductivity of the heat exchanger 6 made of the second metal can be improved.

[0074] Conventional heat exchangers include a serpentine heat exchanger and a parallel-flow heat exchanger made of aluminum. Both the serpentine heat exchanger and the parallel-flow heat exchanger comprise a fin and a refrigerant line. In the serpentine heat exchanger, aluminum is generally used as the material for a fin, and copper is generally used as the material for a refrigerant line. When iron is used as the material for the shell 2, the order of magnitude between the respective standard electrode potentials of the metals is as follows: Aluminum <Eisen<Kupfer. Das heißt, die Größenordnung zwischen den jeweiligen Standardelektrodenpotentialen der Metallmaterialien ist wie folgt: Rippe < Gehäuse 2 < Kältemittelleitung.When the fin and the refrigerant pipe of the serpentine heat exchanger are brought into direct contact with the shell 2 and moisture is present at a part of the contact between the fin and the shell 2 and a part of the contact between the refrigerant pipe and the shell 2, corrosion may occur in the fin which has a standard electrode potential lower than that of the shell 2, but corrosion does not occur in the refrigerant pipe which has a standard electrode potential higher than that of the shell 2.

[0075] Meanwhile, aluminum is used as the material for the fin and refrigerant pipe in the aluminum-made parallel-flow heat exchanger. Therefore, if iron is used as the material for the casing 2, corrosion may occur in both the fin and the refrigerant pipe. If corrosion occurs in the refrigerant pipe and a hole is formed, refrigerant in the refrigerant pipe will leak into the atmosphere. The leakage of refrigerant into the atmosphere will impair the cooling and heating function of an air conditioner. As described above, the negative effects of corrosion are great in an aluminum parallel-flow heat exchanger. Therefore, it is extremely important to take measures to prevent corrosion, and it is also necessary to take measures to reduce electromagnetic noise generated due to the corrosion prevention measures.Therefore, it is particularly useful to both prevent corrosion and reduce electromagnetic interference by using the non-metallic conductive materials 3 as in the first embodiment in . Fig. 12, can be used when using a heat exchanger with a large negative corrosion effect, such as the parallel-flow aluminum heat exchanger. In other words, the use of the non-metallic conductive materials 3 as in the first embodiment, which achieves both corrosion protection and electromagnetic noise reduction, is particularly useful when using a heat exchanger in which the self-potential of the refrigerant line is lower than the self-potential of a peripheral material such as the casing 2.

[0076] Note that the installation location and shape of each conductive material 3 are not limited to those shown in the drawing. For example, the conductive materials 3 can be attached to the housing bottom member 2a, the housing ceiling member 2b, or the like, or electrically connected to any surface of the heat exchanger 6. The shape of each conductive material 3 can be changed accordingly so that the conductive material 3 can be electrically connected to the housing 2 and the heat exchanger 6.

[0077] The entire heat exchanger 6 does not always have to be made of the second metal, and at least a portion of the heat exchanger 6 must be made only of the second metal. For example, the fins or the refrigerant lines of the heat exchanger 6 must be made only of the second metal.

[0078] The configurations described in the above-mentioned embodiment show examples, and it is possible to combine the configurations with another known technique, and it is also possible to partially omit or change the configurations without departing from the scope of the present disclosure. List of reference symbols 1 outdoor unit of an air conditioning system; 2 housings; 2a Housing base element; 2b Housing ceiling element; 2c first coupling element; 2d second coupling element; 2e front housing element; 2f, 2g housing side element; 2h case back element; 2i air intake; 2j air outlet; 2k opening; 2m interior area; 3 conductive material; 3a first conductive material; 3b second conductive material; 3c first part of the plate; 3d second plate part; 3e fixed part; 3f plate part; 3g coupling part; 4 separating element; 4a first separation; 4b second separation; 4c insertion hole; 4d, 6i side surface; 5 fans; 5a bracket; 5b blower motor; 5c Propeller fan; 6 heat exchangers; 6a first heat exchanger unit; 6b second heat exchanger unit; 6c 6d: line distributor; 6e refrigerant line; 6f rib; 6g , 6h front surface; 7 Insulating material; 7a first insulating material; 7b second insulating material; 8 compressor; 8a Motor winding; 8b, 22a, 22b parasitic capacitance; 8c contact resistance; 8d Neutral point of the three-phase motor winding; 9 boxes for electronic substrates; 9a lower box; 9b upper cover; 9c electronic substrate; 9d heat sink; 9th hole; 10 blower chamber; 11 electrical chamber; 12 Blower drive wire; 13 compressor drive wires; 14 external AC lines; 15 internal power lines; 16 ground wire; 17 shut-off valve; 18 refrigerant line; 19 connecting section; 20 interface element; 20a vertical interface element; 20b upper connecting flange section; 20c transverse interface element; 20d lower connecting flange section; 20e Earth connection point; 21 terminal block; 22 interface cover; 23, 24 parasitic inductance.

Claims

[1] Outdoor unit (1) of an air conditioning system, comprising: a housing (2) made of a first metal, wherein the housing (2) has a box shape; a heat exchanger (6) arranged in the housing (2) and attached to the housing (2) via a non-conductive material (7), wherein at least a part of the heat exchanger (6) is made of a second metal, wherein the second metal is different from the first metal with respect to its intrinsic potential; and a conductive material (3) made of a non-metal, wherein the conductive material (3) is arranged in the housing (2), wherein the conductive material (3) is attached to the housing (2) and electrically connected to the housing (2) and electrically connected to the heat exchanger (6). [2] Outdoor unit (1) of an air conditioning system according to claim 1, wherein the housing (2) comprises: a housing base element (2a); a housing cover element (2b) arranged above the housing base element (2a); a housing front element (2e) configured to couple the housing bottom element (2a) to the housing top element (2b); a housing back element (2h); and Housing side elements (2f, 2g), wherein the conductive material (3) is attached to the housing base element (2a), the housing cover element (2b), the housing front element (2e), the housing rear element (2h) and / or to the housing side elements (2f, 2g). [3] The outdoor unit (1) of an air conditioner according to claim 1 or 2, wherein a self-potential of the first metal is higher than a self-potential of the second metal. [4] Outdoor unit (1) of an air conditioning system according to one of claims 1 to 3, wherein the first metal is iron or an iron alloy, and wherein the second metal is aluminum or an aluminum alloy. [5] Outdoor unit (1) of an air conditioning system according to one of claims 1 to 4, wherein the heat exchanger (6) is a parallel flow heat exchanger.

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