JP2011018865A - Safety device for solar cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety device for solar cell systems capable of reliably protecting power conditioners of solar cell systems from lightning surge.SOLUTION: The safety device 150 for a solar cell system 110 protects a power conditioner of the solar cell system from lightning surge, when the solar cell system 110 is installed on a house 10 having a distribution panel 40, in which a solar cell array 80 is connected to the distribution panel 40 via the power conditioner 100. The system includes a commercial power supply side arrestor 120 connected to a wiring in the distribution panel or a wiring between the distribution panel and the power conditioner; and a solar cell side arrestor 130 connected to a wiring in a connection box 90 disposed between the solar cell array and the power conditioner or a wiring between the connection box and the power conditioner. The commercial power supply side arrestor and the solar cell side arrestor are grounded by a common earth cable 61.

Description

  The present invention relates to a solar cell system security device, and more particularly to a solar cell system security device for protecting a power conditioner of a solar cell system from a lightning surge.

  Conventionally, in order to protect various electrical devices in a house from lightning surges, a lightning surge protector called an arrester or SPD (Surge Protective Device) along with a breaker is installed on the panel of a residential distribution board. Is known (see, for example, Patent Document 1).

  By providing such a lightning surge protector, even if a lightning surge occurs from the commercial power supply side, it is possible to prevent the lightning surge from being transmitted to the electrical equipment connected to the distribution board.

  On the other hand, the distribution board where the lightning surge protector is installed is often installed at a position higher than the eye level of the resident, and it is difficult to see whether the SPD function is operating normally. There are many. Therefore, the SPD described in Patent Document 1 includes a light-emitting element that is turned on when the SPD function is normal, so that the status display of the SPD function can be reliably performed for the convenience of residents.

JP 2008-125259 A

  By the way, in recent years, from the viewpoint of environmental considerations and reduction of utility costs, the number of houses where solar cell systems are installed is increasing. A solar cell system is a solar cell array consisting of solar cell modules installed at a position with a large amount of sunlight, such as a roof of a house, and the output of positive and negative electrodes in units of solar cell modules or multiple solar cell modules. Wiring is provided. And the wiring from a some positive electrode and a negative electrode is put together in a connection box (relay terminal box), and is connected to a power conditioner. In the power conditioner, the DC voltage supplied from the junction box is converted into an appropriate voltage level, and the DC is converted into AC. And the electric power produced | generated with the power conditioner is supplied to a distribution board, and is distributed and supplied to each electric equipment from a distribution board.

  Here, the power conditioner is an electrical device that may itself be affected by lightning surges, and it is possible that lightning surges may enter from the solar cell side by providing a solar cell array. There was a problem.

  Then, an object of this invention is to provide the security device for solar cell systems which can protect the power conditioner of a solar cell system from a lightning surge reliably.

In order to achieve the above object, a safety device for a solar cell system according to a first aspect of the present invention is a housing having a distribution board for distributing commercial power, a solar cell array is connected to the distribution board via a power conditioner. A solar cell system safety device for protecting the power conditioner of the solar cell system from lightning surge when the solar cell system is installed by
A commercial power supply side arrester connected to the wiring in the distribution board or the wiring between the distribution board and the power conditioner;
A wiring in a junction box provided between the solar cell array and the power conditioner or a solar cell-side arrester connected to a wiring between the junction box and the power conditioner;
The commercial power supply side arrester and the solar cell side arrester are grounded by a common ground wire.

  Thereby, the arrester can be provided so as to be sandwiched from the distribution board side and the solar cell side having the wiring connected to the power conditioner, and the power conditioner can be reliably protected.

2nd invention is the security device for solar cell systems which concerns on 1st invention,
The commercial power supply side arrester and the solar cell side arrester are both provided in the junction box.

  Thereby, an arrester can be gathered in the junction box by the side of a solar cell system, can be provided by one point grounding, and even if it is a case where a solar cell system is retrofitted, an arrester can be provided in a space-saving manner.

3rd invention is the security device for solar cell systems which concerns on 2nd invention,
The connection point to the common ground wire of the commercial power supply side arrester and the solar cell side arrester is provided in the connection box,
The lengths of the wiring between the commercial power supply side arrester and the connection point and the wiring between the solar cell side arrester and the connection point are both within 50 cm.

  As a result, the distance between the arrester and the common ground line can be shortened, and a potential difference can be prevented from occurring between each arrester line and the common ground line.

4th invention is the security device for solar cell systems which concerns on 1st invention,
The commercial power supply side arrester is provided in the distribution board,
The solar cell side arrester is provided in the junction box.

  As a result, when an arrester for normal electrical equipment is already installed in the distribution board, the existing arrester can be used to provide a wiring configuration that prevents destruction of the power conditioner of the solar cell system. it can.

5th invention is the security device for solar cell systems which concerns on 1st invention,
The common ground wire of the commercial power supply ares and the solar cell side arrester are both provided in the distribution board.

  As a result, when an arrester is already provided on the distribution board side, it is possible to provide an arrester on the solar cell side in the distribution board using not only the arrester but also the ground wire, The combined power conditioner can be protected from lightning surges.

A sixth invention is a solar cell system security device according to the fifth invention,
The connection point to the common ground wire of the commercial power supply side arrester and the solar cell side arrester is provided in the distribution board,
The lengths of the wiring between the commercial power supply side arrester and the connection point and the wiring between the solar cell side arrester and the connection point are both within 50 cm.

  As a result, the wiring distance between the arrester and the common ground wire can be shortened, and the occurrence of a potential difference between the wirings can be prevented.

7th invention is the security device for solar cell systems which concerns on any 1st-6th invention,
The common ground wire is grounded by D-type grounding.

  Thereby, the grounding suitable for a house can be performed.

  ADVANTAGE OF THE INVENTION According to this invention, the power conditioner of a solar cell system can be reliably protected from a lightning surge.

It is the figure which showed an example of the power supply system of the house 10 before solar cell system installation. It is the figure which showed an example of the whole structure of the solar cell system security device 150 which concerns on Example 1. FIG. It is the figure which showed an example of the power supply system of the house 10 before solar cell system installation. It is the figure which showed an example of the whole structure of the security apparatus 151 for solar cell systems which concerns on Example 2. FIG. It is the figure which showed an example of the whole structure of the safety device 152 for solar cell systems which concerns on the modification of Example 2. FIG. It is the figure which showed an example of the whole structure of the solar cell system security device 153 which concerns on Example 3. FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating an example of a power supply system of a house 10 in which no solar cell system is installed. In FIG. 1, commercial power is supplied from a distribution line 21 on a utility pole 20 to a residential area. From the distribution line 21, it is converted to 100 V by the pole transformer 22, and commercial power is supplied to each house 10 through the lead-in wire 23. The lead-in wire 23 is connected to the distribution board 40 in the house 10. And the electrical appliances 50 and 51 are connected to the distribution board 40 via an outlet, and electric power is distributed and supplied from the distribution board 40 to the electrical appliances 50 and 51. Further, a watt-hour meter 30 for demand power is connected between the lead-in wire 23 and the distribution board 40 so that the demand power amount can be measured. The distribution board 40 is grounded by a ground wire 60. In FIG. 1, a lightning surge protector called arrester or SPD for lightning surge countermeasures is not installed. Hereinafter, the lightning surge protector will be collectively referred to as an arrester, but the arrester according to the present embodiment includes various lightning surge protectors.

  As shown in FIG. 1, the arrester is arbitrarily installed in each house 10 for lightning surge countermeasures, and is not necessarily installed in all houses 10. In Example 1, a solar cell system security device suitable for the house 10 when an arrester is not installed will be described before the installation of the solar cell system.

  FIG. 2 is a diagram illustrating an example of the overall configuration of the solar cell system security device 150 according to the first embodiment of the present invention. In FIG. 2, a solar cell system 110 is newly installed in the house 10.

  The solar cell system 110 includes a solar cell array 80, a solar cell array wiring 81, a connection box 90, and a power conditioner 100. The solar cell array 80 includes a plurality of solar cell modules 70. Moreover, with the introduction of the solar cell system 110, a surplus power watt-hour meter 31 for selling surplus power to an electric power company is provided.

  On the other hand, the solar cell system security device 150 according to this embodiment includes a commercial power supply side arrester 120, a solar cell side arrester 130, and a common ground wire 61.

  The solar cell system 110 is a power generation system that receives sunlight from the sun 160 and converts it into electric power. The solar cell module 70 is an aggregate of several hundred solar cells having a size of about 10 cm for receiving sunlight and converting it into DC power. For example, one side has a size of 1 to 2 m. . Further, the solar cell array 80 is formed by connecting several tens of solar cell modules 70, and constitutes a solar cell panel as a whole.

  The DC power generated in the solar cell array 80 is sent to the connection box 90 via the solar cell array wiring 81. The connection box 90 is means for collecting DC power composed of a plurality of circuits from the solar cell array 80 into one circuit. The connection box 90 may be called a relay terminal box. The DC power collected in one circuit in the connection box 90 is sent to the power conditioner 100.

  The power conditioner 100 is means for converting DC power sent from the connection box 90 into AC 100V used in the house 10. Therefore, the power conditioner 100 has a function as a transformer and a function as an inverter. The power conditioner 100 is connected to the distribution board 40 by the wiring 101 and supplies AC power to the distribution board 40.

  Further, the surplus power remaining after the power is supplied from the distribution board 40 to the electric appliances 50 and 51 is measured by the surplus power watt-hour meter 31 and sold to the power company.

  Here, when the solar cell system 110 is installed in the house 10, the solar cell array wiring 81 is added as a lightning surge entry path. Lightning surge can be thought of in various ways, such as commercial power distribution line 21 and lead-in line 23, communication antenna, communication wiring, and ground wire connected to the ground. There are many electrical wires drawn into the house 10. Since the battery array wiring 81 is also drawn into the house 10 through the roof, it can be a factor inducing a lightning surge. And the lightning surge from the solar cell array wiring 81 may destroy the power conditioner 100.

  Therefore, in the solar cell system security device 150 according to the present embodiment, the commercial power supply side arrester 120 and the solar cell side arrester 130 are respectively connected to the wirings 101 and 102 that are electrical connection paths of the power conditioner 100. is doing. Thereby, all the arresters 120 and 130 for a lightning surge countermeasure are provided in the connection path | route of the power conditioner 100, and the power conditioner 100 can be protected reliably. That is, the commercial power supply-side arrester 120 protects the power conditioner 100 by causing a lightning surge induced from the distribution line 21 and the lead-in wire 23 that are wiring on the commercial power supply side to flow to the ground using the ground wire 61. be able to. Similarly, the solar cell side arrester 130 can protect the power conditioner 100 by flowing a lightning surge induced from the solar cell array wiring 81 to the ground using the ground wire 61.

  Further, the commercial power supply-side arrester 120 and the solar cell-side arrester 130 are connected to the ground wire 61 in common at the connection point 65. For a lightning surge, it is preferable to install a plurality of arresters 120 and 130 and to coordinate them. In particular, common grounding (bonding) is important. By making the ground potential equal, it is possible to prevent a situation in which a potential difference occurs between the plurality of arresters 120 and 130. The common ground wire 61 may be grounded according to, for example, a D-type grounding standard. For the house 10, it is possible to perform a level of construction suitable for the application.

  The commercial power supply side arrester 120 and the solar cell side arrester 130 are both provided in the junction box 90. Accordingly, since the commercial power supply side arrester 120 and the solar cell side arrester 130 newly provided with the installation of the solar cell system 110 are also provided in the newly provided connection box 90, the commercial power supply side arrester 120 and the solar cell side arrester are also provided. There is no need to externally attach 130, and space can be saved. As described with reference to FIG. 1, when the distribution board 40 has not been provided with an arrester from the beginning, there is often no space in the distribution board 40 where a new arrester is newly provided. Even in such a case, according to the solar cell system security device 150 according to the present embodiment, since the commercial power supply side arrester 120 is also installed in the newly provided connection box 90, the existing distribution board 40 The commercial power supply-side arrester 120 for the power conditioner 100 can be installed without making an unreasonable change.

  In the solar cell system security device 150 according to the present embodiment, the connection point 65 to the common ground wire 61 is also provided in the connection box 90. By bonding within the junction box 90, the length of the wiring between the commercial power supply-side arrester 120 and the common connection point 65 to the common ground wire 61, and the connection point 65 to the common ground wire 61 of the solar cell side arrester 130 are obtained. The length of the wiring can be shortened. The shorter the length of the wiring between the arresters 120, 130 and the common ground wire 61, the less potential difference is generated. For example, the wiring between the commercial power supply side arrester 120 and the solar cell side arrester 130 and the connection point 65 is preferably 50 cm or less. The connection point 65 is also provided in the connection box 90 in the same manner as the commercial power source side arrester 120 and the solar cell side arrester 130, so that the length of the connection wiring to the common ground wire 61 of the arresters 120 and 130 can be easily within 50 cm. It can be set as a preferable structure also as a lightning surge countermeasure.

  As described above, according to the solar cell system security device 150 according to the first embodiment, since both the commercial power supply side arrester 120 and the solar cell side arrester 130 are provided in the newly provided connection box 90, installation work can be easily performed. can do. Moreover, since the distance of the connection wiring of the commercial power supply side arrester 120 and the solar cell side arrester 130 and the common ground wire 61 can be shortened to 50 cm or less, it is possible to effectively take a lightning surge countermeasure.

  FIG. 3 is a diagram illustrating an example of a power supply system of the house 10 before the solar cell system is installed. 3 is different from FIG. 1 in that a commercial power supply side arrester 121 is provided in the distribution board 40. Other components are the same as those shown in FIG. 1 and are therefore denoted by the same reference numerals and the description thereof is omitted.

  As shown in FIG. 3, a commercial power supply side arrester 121 for lightning surge countermeasures may be provided in the distribution board 40 before the installation of the solar cell system 110. Further, the commercial power supply side arrester 121 is grounded by a ground wire 60. The ground wire 60 may be grounded, for example, by D-type grounding work. In such a case, with respect to the electrical appliances 50 and 51 connected to the distribution board 40, protection measures have already been taken for the lightning surge induced from the commercial power source side, that is, the distribution line 21 and the lead-in line 23. become.

  FIG. 4 is a diagram illustrating an example of the overall configuration of the solar cell system security device 151 according to the second embodiment. In FIG. 4, the solar cell system 110 is installed in the house 10, but the solar cell system 110 itself is the same as the solar cell system 110 described in the first embodiment. The description is omitted.

  The solar cell system security device 151 according to the second embodiment includes the solar power system arrester 121, the solar battery side arrester 131, and the common ground wire 62 as constituent elements. Common with battery system security device 150.

  However, in the solar cell system safety device 151 according to the second embodiment, the commercial power supply side arrester 121 and the solar battery side arrester 130 are both provided in that the commercial power supply side arrester 121 is provided in the distribution board 40. This is different from the safety device for the solar cell stopping system according to the first embodiment provided in the connection box 90.

  In the solar cell system security device 151 according to the second embodiment, the commercial power supply side arrester 121 is provided in the distribution board 40 in the same manner as before the solar cell system 110 is installed, and the power conditioner 100 is connected via a wiring 101. That is, the solar cell system 151 according to the second embodiment uses the commercial power supply side arrester 121 provided in the distribution board 40 before the solar cell system 110 is installed as it is. Thereby, even if the power conditioner 100 used as the protection object of a new lightning surge is added by the installation in the house 10 of the solar cell system 110, it will be lightning surge induced from the distribution line 21 and the lead-in line 23 on the commercial power source side. On the other hand, the power conditioner 100 can be protected as it is by using the existing commercial power supply side arrester 121.

  On the other hand, the solar cell side arrester 131 is installed in the terminal box 90 of the solar cell system 110 and is connected to the power conditioner 100 by the wiring 102. Since the solar cell side arrester 131 is newly installed with the introduction of the solar cell system 110, it is installed in the connection box 90 in the solar cell system 110 to save space. With the introduction of the solar cell system 110, by providing the solar cell side arrester 131, the power conditioner 100 can be protected from a lightning surge that enters from the solar cell array wiring 81.

  The solar cell side arrester 131 and the commercial power source side arrester 121 are both connected to a common ground wire 62 at a connection point 66. The solar cell side arrester 131 is directly connected to the common ground wire 62, and the commercial power source side arrester 121 is connected to the common ground wire 62 via the power conditioner 100. Since the solar cell side arrester 131 and the commercial power source side arrester 121 are connected to a common ground wire 62 and are grounded at one point, the solar cell side arrester 131 and the commercial power source side arrester 121 can be kept at the same potential. , Lightning surge can surely flow to the ground.

  Thus, when the commercial power supply side arrester 121 for protecting the electric appliances 50 and 51 is provided in the distribution board 40 before the installation of the solar cell system 110, this is used for the commercial use of the power conditioner 100. The power supply side arrester 121 may be used as it is, and the solar cell side arrester 131 may be newly provided in the connection box 90 only on the solar cell side. Thereby, the labor and cost of the construction can be reduced, and the power conditioner 100 can be appropriately protected from lightning surge.

  FIG. 5 is a diagram illustrating an example of the overall configuration of a solar cell system security device 152 according to a modification of the second embodiment. In FIG. 4, the common ground wire 62 is provided on the side of the junction box 90 installed with the introduction of the solar cell system 110. However, in the solar cell system security device 152 according to the modification of the second embodiment of FIG. 5, the common ground wire 63 is provided on the distribution board 40 side. Then, the commercial power supply side arrester 121 is directly connected to the common ground line 63 at the connection point 67, and the solar cell side arrester 131 is connected to the connection point 67 via the power conditioner 100 to share the ground. Is planned.

  In the solar cell system security device 152 according to the modification of the second embodiment, the ground wire 60 shown in FIG. 3 is used as it is as the common ground wire 63 before the solar cell system 110 is installed. . Thereby, also about the common ground wire 63, the ground wire 60 before installation of the solar cell system 110 can be effectively used, and further simplification of construction labor and reduction of construction cost can be achieved.

  Thus, according to the solar cell system security device 151 according to the second embodiment, the existing commercial power supply side arrester 121 in the distribution board 40 can be directly used from the lightning surge on the commercial power supply side for the power conditioner 100. As a countermeasure against lightning surge on the solar cell side, the solar cell side arrester 131 is installed in the junction box 90, so that the power conditioner 100 can be properly protected with a minimum of construction. it can.

  FIG. 6 is a diagram illustrating an example of the overall configuration of the solar cell system security device 153 according to the third embodiment of the present invention. In FIG. 6, since the configuration of the solar cell system 110 is the same as that described so far, the same components are denoted by the same reference numerals and the description thereof is omitted.

  The solar cell system security device 153 according to the third embodiment includes the commercial power supply-side arrester 122, the solar cell-side arrester 132, and the common ground wire 64 as constituent elements. Similar to the second embodiment.

  In the solar cell system security device 153 according to the third embodiment, both the commercial power supply-side arrester 122 and the solar cell-side arrester 132 are provided in the distribution board 40, and a common ground wire 64 in the distribution board 40 is provided. It differs from Example 1 and Example 2 by the point connected to.

  Thus, the solar cell system security device 153 may be configured by installing the commercial power supply side arrester 122 and the solar cell side arrester 132 together in the distribution board 40. For example, if the commercial power arrester 121 is installed in the distribution board 40 as shown in FIG. 3 before the installation of the solar cell system 110, it is left in the distribution board 40 as it is. If the wiring 101 is provided and connected to the power conditioner 100, it can also be used as a commercial power supply side arrester 122 for protecting the power conditioner 100. The commercial power supply side arrester 122 protects the power conditioner 100 together with the appliances 50 and 51 by flowing a lightning surge that enters from the distribution line 21 or the lead-in wire 23 on the commercial power supply side through the common ground wire 64.

  On the other hand, the solar cell side arrester 132 is provided in the distribution board 40, one end is connected to the power conditioner 100 by the wiring 102, and the other end is connected to the common ground wire 64. Therefore, the connection relationship is the same as in Example 1 and Example 2, and the lightning surge that has entered from the solar cell array wiring 81 is caused to flow from the lightning surge on the solar cell side by flowing to the ground through the common ground wire 64. The conditioner 100 can be protected. If there is a space in the distribution board 40 where the solar cell side arrester 132 is newly provided, the solar cell side arrester 132 may be additionally provided in the distribution board 40 as described above.

  In the solar cell system security device 153 according to the third embodiment, the commercial power supply side arrester 122 and the solar cell side arrester 132 are connected to the common ground wire 64 at the connection point 68 in the distribution board 40. ing. Thereby, the length of the wiring from the commercial power source side arrester 122 to the common ground line 64 and the length of the wiring from the solar cell side arrester 132 to the common ground line 64 can be shortened. For example, both wirings can be within 50 cm, which can reduce the potential difference between the commercial power supply-side arrester 122 and the solar cell-side arrester 132 even if a large lightning surge enters the power supply. It is possible to prevent the current from flowing to the conditioner 100 side, and to surely flow from the common ground wire 64 to the ground side.

  As the common ground wire 64, the ground wire 60 shown in FIG. 3 can be used as the common ground wire 64 as it is. This makes it possible to further simplify the construction and reduce the cost.

  Thus, according to the solar cell system security device 153 according to the third embodiment, the commercial power supply-side arrester 121 and the ground wire 60 provided in the distribution board 40 from before the solar cell system 110 is installed, Installation work can be easily performed, and the wiring length between the common ground wire 64, the commercial arrester 122, and the solar cell side arrester 132 can be shortened, and the power conditioner 100 can be reliably protected.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  In particular, in the first to third embodiments, the example in which the solar cell system security devices 150 to 153 are provided is described in consideration of the state before the solar cell system 110 is installed. Regardless of the state, appropriate solar cell system security devices 150 to 153 may be provided according to the application. For example, when the commercial power supply side arrester 121 is not installed before the solar cell system 110 is installed, all the configurations of the first to third embodiments can be easily adopted, and conversely, the commercial power supply arrester 121. May be installed in advance, the construction having the configuration as in the first embodiment may be performed using a higher performance commercial power arrester 120.

  The present invention can be used for a safety device for lightning surge protection for a solar cell system.

DESCRIPTION OF SYMBOLS 10 Housing 20 Electric pole 21 Distribution line 22 Pole transformer 23 Lead-in line 30 Electricity meter for demand electric power 31 Electricity meter for surplus electric power 40 Distribution board 50, 51 Electrical appliance 60 Ground wire 61, 62, 63, 64 Common ground Line 65, 66, 67, 68 Connection point 70 Solar cell module 80 Solar cell array 81 Solar cell array wiring 90 Connection box 100 Power conditioner 101, 102 Wiring 110 Solar cell system 120, 121, 122, 123 Commercial power supply side arrester 130 , 131, 132, 133 Solar cell side arrester 150, 151, 152, 153 Safety device for solar cell system

Claims (7)

When a solar cell system is installed in a house having a distribution board for distributing commercial power by connecting a solar cell array to the distribution board via a power conditioner, the solar cell system A solar cell system safety device for protecting the inverter from lightning surge,
A commercial power supply side arrester connected to the wiring in the distribution board or the wiring between the distribution board and the power conditioner;
A wiring in a junction box provided between the solar cell array and the power conditioner or a solar cell-side arrester connected to a wiring between the junction box and the power conditioner;
The commercial power supply side arrester and the solar cell side arrester are grounded by a common ground wire, and the solar cell system security device.   2. The solar cell system security device according to claim 1, wherein the commercial power supply side arrester and the solar cell side arrester are both provided in the junction box. The connection point to the common ground wire of the commercial power supply side arrester and the solar cell side arrester is provided in the connection box,
The length of the wiring between the commercial power source side arrester and the connection point and the wiring length between the solar cell side arrester and the connection point are both within 50 cm. Security equipment. The commercial power supply side arrester is provided in the distribution board,
The solar cell system security device according to claim 1, wherein the solar cell side arrester is provided in the junction box.   2. The solar cell system security device according to claim 1, wherein both the commercial power supply ares and the common ground wire of the solar cell side arrester are provided in the distribution board. The connection point to the common ground wire of the commercial power supply side arrester and the solar cell side arrester is provided in the distribution board,
The length of the wiring between the commercial power source side arrester and the connection point and the wiring between the solar cell side arrester and the connection point are both within 50 cm, for the solar cell system according to claim 5. Security equipment.   The solar cell system security device according to any one of claims 1 to 6, wherein the common ground wire is grounded by D-type grounding.

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