Lighting systems and plant factories

Abstract

Addressing electrical leakage in lighting systems applied to plant factories. [Solution] The lighting system applied to the plant factory comprises a lighting device including LED elements and a single-phase two-wire power supply circuit that supplies power to the lighting device from an external power source. The power supply circuit comprises a power transmission unit that constitutes a power supply path that sends power from the external power source to the lighting device, and a ground fault circuit breaker provided in the power supply path that cuts off the power supply to the lighting device when a ground fault is detected. The power transmission unit comprises a plurality of cables provided in the section between the ground fault circuit breaker and the lighting device in the power supply path, and a connector that connects the plurality of cables. The lighting system comprises a grounding unit that grounds the connector.

Description

Technical Field

[0001] The present invention relates to a lighting system and a plant factory.

Background Art

[0002] There are known a leakage detection device (Patent Document 1) that detects leakage due to a tracking phenomenon and a leakage fire alarm (Patent Document 2) installed in a fire prevention object defined by the Fire Prevention Law.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a plant factory, relatively large-scale lighting equipment is often provided, and it is desirable to deal with leakage when supplying power to the lighting equipment.

[0005] According to one aspect of the present invention, a technique for dealing with leakage in a lighting system applied to a plant factory is provided.

Means for Solving the Problems

[0006] The present invention may include the following aspects. [Aspect 1] A lighting system applied to a plant factory, a lighting device including an LED element, a single-phase two-wire power supply circuit that supplies power from an external power source to the lighting device, and the power supply circuit A power transmission unit that constitutes a power supply path for sending power from an external power source to the lighting device, A ground fault circuit breaker is provided in the power supply path and, when a ground fault is detected, shuts off the power supply to the lighting device. It consists of, The aforementioned power transmission unit is Multiple cables are provided in the section between the leakage circuit breaker and the lighting device in the power supply path, Includes a connector for connecting the aforementioned multiple cables, The lighting system includes a grounding section for grounding the connector. Lighting system. [Aspect 2] The lighting system described in Embodiment 1, The grounding portion includes a conductor that contacts the connector, and the connector is grounded by the conductor being electrically connected to the growing shelves in the plant factory. Lighting system. [Aspect 3] The lighting system described in Embodiment 2, The growing shelf which is in electrical contact with the conductor of the grounding portion, A plant factory equipped with these features. [Effects of the Invention]

[0007] According to the present invention, a technique for dealing with electrical leakage in a lighting system applied to a plant factory is provided. [Brief explanation of the drawing]

[0008] [Figure 1] Schematic diagram of the circuit configuration of a lighting system applied to a plant factory according to one embodiment. [Modes for carrying out the invention]

[0009] [Overview of plant factories] FIG. 1 shows the circuit configuration of the lighting system 1 applied to the plant factory P according to an embodiment. The plant factory P includes a growth chamber (not shown) and the lighting system 1. In this specification, the plant factory P refers to a system capable of artificially cultivating plants. For example, in the growth chamber of the plant factory P, in addition to the lighting system 1 described later, there are production shelves for plants (not shown) on which the cultivated plants are placed, an air conditioner for maintaining the temperature, humidity, etc. in the growth chamber suitable for the growth of the cultivated plants, and a device for supplying carbon dioxide to the cultivated plants in the growth chamber, etc.

[0010] [Lighting System] <Overview> The lighting system 1 is a system applied to the plant factory P, and includes a lighting device 11 and a power supply circuit 12. The lighting system 1 illuminates the plants in the plant factory with the power supplied from the external power source 2.

[0011] The lighting device 11 includes LED elements. For example, the LED elements of the lighting device 11 can emit light with wavelengths necessary for the photosynthesis of the cultivated plants and are used as an artificial light source in the plant factory P. A plurality of LED elements of the lighting device 11 can be provided in the growth chamber.

[0012] The power supply circuit 12 supplies power from the external power source 2 to the lighting device 11. In this embodiment, the power supply circuit 12 is a single-phase two-wire circuit. In the case of AC power supply, either a three-phase or single-phase system can be adopted, but the single-phase system is often used. Also, for single-phase, there are single-phase two-wire and single-phase three-wire, but the single-phase two-wire system is often used for cost reduction. The power supply circuit 12 includes a power transmission unit 121 and a leakage breaker 122.

[0013] The power transmission unit 121 constitutes a power supply path 121a for sending the power from the external power source 2 to the lighting device 11. The power transmission unit 121 includes cables 1211a to 1211c and a connector 1212.

[0014] Cable 1211a is provided between the external power supply 2 and the earth leakage circuit breaker 122. Cable 1211b is provided between the earth leakage circuit breaker 122 and the connector 1212. Cable 1211c is provided between the connector 1212 and the lighting device 11. That is, cables 1211b and 1211c are provided in the section between the earth leakage circuit breaker 122 and the lighting device 11 in the power supply path 121a. The connector 1212 connects the cable 1211b and the cable 1211c in the section between the earth leakage circuit breaker 122 and the lighting device 11 in the power supply path 121a. Since the lighting system 1 of this embodiment is used inside the plant factory P, there is a possibility that moisture such as nutrient solution supplied to plants adheres to the connector 1212. Therefore, the connector 1212 may be of a waterproof specification.

[0015] Cable 1211a includes a conductor 1211a1 which is a power supply line and 1211a2 which is a return line. Cable 1211b includes a conductor 1211b1 which is a power supply line and 1211b2 which is a return line. Cable 1211c includes a conductor 1211c1 which is a power supply line and 1211c2 which is a return line.

[0016] The earth leakage circuit breaker 122 is a device that cuts off the power supply to the load when detecting an earth leakage. As the earth leakage circuit breaker 122, a known one can be appropriately used. In this embodiment, the earth leakage circuit breaker 122 includes a zero-phase current transformer 1221, an electronic circuit 1222, and an electromagnetic switch 1223.

[0017] The zero-phase current transformer 1221 detects the earth leakage of the circuit. The zero-phase current transformer 1221 is provided with an opening through which the power supply line and the return line pass inside. When an earth leakage occurs, a current difference occurs in the power supply line and the return line passing inside this opening. When the zero-phase current transformer 1221 detects this current difference, it transmits a voltage signal corresponding to the current difference to the electronic circuit 1222.

[0018] The electronic circuit 1222 controls the opening and closing of the electromagnetic switch 1223 based on the signal from the zero-phase current transformer 1221. For example, based on the voltage signal from the zero-phase current transformer 1221, the electronic circuit 1222 outputs an operation command for the electromagnetic switch 1223 when the leakage current exceeds a set value.

[0019] The electromagnetic switch 1223 interrupts the flow of current within the earth leakage circuit breaker 122. The electromagnetic switch 1223 operates upon receiving an operation command from the electronic circuit 1222, physically opening the circuit and interrupting the flow of current.

[0020] <Grounding of the connector> In this embodiment, the lighting system 1 further includes a grounding section 13 that grounds the connector 1212 of the power transmission section 121. In this embodiment, the grounding section 13 includes a conductor 131 that contacts the connector 1212, and the connector 1212 is grounded by the conductor 131 making electrical contact with the growing shelves in the plant factory P. For example, the conductor 131 may be made of aluminum. Alternatively, the grounding section 13 may be constructed by attaching the connector 1212 to the growing shelves with aluminum tape. The configuration of the grounding section 13 can be changed as appropriate, as long as the connector 1212 is grounded.

[0021] As described above, since the lighting system 1 of this embodiment is used in a plant factory P, moisture such as nutrient solution supplied to plants may adhere to the connector 1212. Nutrient solution may contain salt, and if this salt precipitates, tracking may occur at the connector 1212. If the grounding section 13 is not provided, in a single-phase two-wire circuit configuration, even if tracking occurs at the connector 1212 between the earth leakage breaker 122 and the lighting device 11, the earth leakage breaker 122 may not be able to detect the earth leakage. This is because, since there is no current difference between the power supply line and the return line, even if tracking occurs, it is not possible to determine whether the flowing current is a fault current or a normal load current, and the current continues to flow. If the current continues to flow, it may lead to overheating and ignition.

[0022] In contrast, in this embodiment, the lighting system 1 is equipped with a grounding section 13 that grounds the connector 1212. This allows the lighting system 1 to intentionally ground the connector 1212 when tracking occurs, thereby creating a current difference between the power supply line and the return line, and enabling the leakage circuit breaker 122 to detect the leakage and shut off the circuit. Thus, it is possible to deal with leakage appropriately. The grounding resistance of the grounding section 13 can be appropriately set according to the power supply voltage and the set sensitivity of the leakage circuit breaker 122, but for example, 150Ω or less, and more preferably 10Ω or less, is desirable (in accordance with the Technical Standards for Electrical Installations). [Explanation of Symbols]

[0023] 1 Plant factory, 1 lighting system, 11 lighting device, 12 power supply circuit, 1212 connector, 13 grounding section

Claims

1. A lighting system applicable to plant factories, A lighting device including LED elements, A single-phase two-wire power supply circuit that supplies power to the lighting device from an external power source, Equipped with, The aforementioned power supply circuit is A power transmission unit that constitutes a power supply path for sending power from an external power source to the lighting device, A ground fault circuit breaker is provided in the power supply path and, when a ground fault is detected, shuts off the power supply to the lighting device. It consists of, The aforementioned power transmission unit is Multiple cables are provided in the section between the leakage circuit breaker and the lighting device in the power supply path, Includes a connector for connecting the aforementioned multiple cables, The lighting system includes a grounding section for grounding the connector. Lighting system.

2. A lighting system according to claim 1, The grounding portion includes a conductor that contacts the connector, and the connector is grounded by the conductor being electrically connected to the growing shelves in the plant factory. Lighting system.

3. The lighting system according to claim 2, The growing shelf which is in electrical contact with the conductor of the grounding portion, A plant factory equipped with these features.

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