A safety device for three-phase four-wire output short circuit protection for laboratories

Abstract

The utility model discloses a three -phase four -line output short -circuit protection's insurance equipment for laboratory, including PCBA circuit board, the top of PCBA circuit board is connected with the protection box, the both sides of protection box all are established with four groups of wire hole, be provided with three groups of short -circuit protection mechanism that are connected with the firewire LA, firewire LB and firewire LC on PCBA circuit board. The utility model discloses the firewire is directly cut off and connects short -circuit protection mechanism, and each group of short -circuit protection mechanism includes two groups of polarity opposite diode group, and each diode group includes four series connection diodes D, makes the current no matter by the input end or the output end of firewire enters and is not affected, and in diode group parallel LED pilot lamp is as indicating signal, and the voltage on LED pilot lamp is decided by four diodes D, and the voltage of PN junction on diode D is related with the size of current, therefore, the brighter LED pilot lamp represents the greater load.

Description

Technical Field

[0001] This utility model relates to the field of electrical equipment protection technology, specifically a fuse device for three-phase four-wire output short circuit protection in a laboratory. Background Technology

[0002] In three-phase power supply laboratory work, when product quality issues or short-circuit faults exist, the instantaneous fault current generated after these products are powered on may be tens to hundreds of times the rated current. When a short circuit occurs in the circuit, the current will increase instantaneously, potentially far exceeding the circuit's carrying capacity. At this time, the powerful electrodynamic force generated by the short-circuit current may damage electrical equipment or power distribution lines, generate electric arcs, or even cause a fire.

[0003] Some power supply equipment has internal protective measures such as fuses. The basic principle of a fuse is to add a metal wire or iron wire into the circuit, and set the protection current value according to the melting point of the metal wire. When an excessive current occurs in the circuit, the metal wire will melt, thereby cutting off the circuit and protecting the equipment. However, after a fault occurs, the internal fuse will also melt and need to be replaced. Moreover, fuses are also components provided with the equipment, and their quantity is limited. In addition, sometimes the equipment's response capability is insufficient, and the fuse may not melt in time, resulting in equipment damage. Sometimes it can even affect the tripping of indoor equipment rooms, causing significant losses. Therefore, we propose a fuse device for three-phase four-wire output short-circuit protection in laboratories. Utility Model Content

[0004] The purpose of this invention is to provide a fuse device for short-circuit protection of three-phase four-wire output in a laboratory, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a fuse device for short-circuit protection of three-phase four-wire output in a laboratory, including a PCBA circuit board, a protective box is snapped onto the top of the PCBA circuit board, and four sets of wire holes are provided on both sides of the protective box for the live wire LA, live wire LB, live wire LC and neutral wire LN to pass through and exit.

[0006] The PCBA circuit board is equipped with three sets of short-circuit protection mechanisms connected to the live wires LA, LB and LC.

[0007] The short-circuit protection mechanism is connected to the input and output terminals of live wires LA, LB, and LC. The short-circuit protection mechanism includes an LED indicator, a fuse, and a diode group. The diode group consists of four diodes D connected in series. The two groups of diodes have opposite polarities. An LED indicator is connected in parallel to the diode group. A fuse is connected in series to the input terminals of live wires LA, LB, and LC.

[0008] Furthermore, the LED indicator is connected in series with a resistor R.

[0009] Furthermore, the protective box is made of transparent acrylic material.

[0010] Furthermore, the fuse is a time-delay fuse, the rated current of the fuse is 2 amps, and the maximum rated voltage of the fuse is 250 volts.

[0011] Furthermore, the diode D is selected as a rectifier diode.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. This utility model directly cuts off the live wires LA, LB, and LC, and then inserts a short-circuit protection mechanism in the middle of the cut wires. This insertion method is convenient to install and does not affect the normal operation of the entire system.

[0014] 2. Furthermore, each short-circuit protection mechanism includes two groups of four diodes (D), with the two groups of diodes having opposite polarities. This ensures that the current entering from either the input or output terminals of the live wires LA, LB, or LC is unaffected. Additionally, an LED indicator is connected in parallel across the four diodes (D) as an indication signal. A resistor (R) is connected in series with the LED indicator to limit current, which can reduce the power consumption of the LED indicator to some extent. The voltage across the LED indicator is determined by the four diodes (D). The voltage across the PN junction of the diodes (D) is related to the current. Therefore, the brighter the LED indicator, the greater the load it can handle.

[0015] 3. Furthermore, each short-circuit protection mechanism is connected in series with a fuse as a fuse element, so that each of the three-phase power supply can be individually blown after a short circuit occurs at the output.

[0016] 4. The short-circuit protection mechanism is installed on the PCBA circuit board, and the PCBA circuit board is equipped with an acrylic protective box made of transparent material. This allows for timely observation of the operation of the short-circuit protection mechanism and also provides protection after the fuse blows. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural schematic diagram of the present invention;

[0018] Figure 2 This is a schematic diagram of the circuit principle of this utility model.

[0019] In the diagram: 1. PCBA circuit board, 2. Protection box, 3. Cable routing hole. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Please see Figures 1-2 This utility model provides a technical solution: a fuse device for short-circuit protection of three-phase four-wire output in a laboratory, including a PCBA circuit board 1, a protective box 2 snapped onto the top of the PCBA circuit board, the protective box 2 being made of transparent acrylic material, and four sets of wire holes 3 for the live wire LA, live wire LB, live wire LC and neutral wire LN to pass through and exit on both sides of the protective box 2; the PCBA circuit board 1 is provided with three sets of short-circuit protection mechanisms connected to the live wire LA, live wire LB and live wire LC.

[0022] Among them, after the three sets of connecting wires of the three-phase four-wire circuit, the live wire LA, live wire LB and live wire LC are cut off, the input and output terminals can pass through multiple sets of wire holes on the left and right sides and connect with the short circuit protection mechanism on the PCBA circuit board 1. The neutral wire LN passes directly through the wire hole 3. The acrylic protection box 2 made of transparent material can observe the working status of the short circuit protection mechanism in time, and can also protect the operator after the fuse blows.

[0023] The short-circuit protection mechanism is connected to the input and output terminals of live wires LA, LB, and LC. The short-circuit protection mechanism includes an LED indicator, a fuse, and a diode group. The diode group consists of four diodes D connected in series. The two groups of diodes have opposite polarities. An LED indicator is connected in parallel to the diode group. A fuse is connected in series to the input terminals of live wires LA, LB, and LC.

[0024] Each short-circuit protection mechanism includes two diode groups, each consisting of four diodes D connected in series. The two groups of diodes have opposite polarities, ensuring that the current is unaffected regardless of whether it enters from the input or output terminals of the live wires LA, LB, or LC. Furthermore, an LED indicator is connected in parallel with each of the four diodes D as an indication signal. The voltage on the LED indicator is determined by the four diodes D. The voltage across the PN junction of the diodes D is related to the current magnitude; therefore, the brighter the LED indicator, the greater the load it can handle.

[0025] Please see Figure 2The LED indicator is connected in series with a resistor R. The resistor R connected in series with the LED indicator can be used as a current-limiting resistor, which can reduce the power consumption of the LED indicator to a certain extent.

[0026] Please see Figure 1 and Figure 2 The fuse is a time-delay fuse with a rated current of 2 amps and a maximum rated voltage of 250 volts. Each short-circuit protection mechanism has a fuse connected in series as a fusing element, so that each of the three-phase power supplies can be individually blown after a short circuit occurs at the output.

[0027] Please see Figure 1 and Figure 2 The diode D is a rectifier diode. The maximum average forward rectified current of the rectifier diode is 1A and the maximum reverse peak voltage is 1000V. The three-phase four-wire output short-circuit protection mechanism in the laboratory does not need to process very high frequency signals. Therefore, the slow recovery diode such as the rectifier diode is more applicable and relatively inexpensive, which helps to reduce the overall cost.

[0028] In use, firstly, after the three sets of connecting wires of the three-phase four-wire system—live wire LA, live wire LB, and live wire LC—are cut off, the input and output terminals can pass through multiple sets of wire holes on the left and right sides and connect to the short-circuit protection mechanism on PCBA circuit board 1. The neutral wire LN passes directly through wire hole 3. The acrylic protection box 2, made of transparent material, allows for timely observation of the short-circuit protection mechanism's operation and also protects the operator after the fuse blows. Each short-circuit protection mechanism includes two sets of diode groups, each consisting of four diodes D connected in series. The diode groups have opposite polarities, ensuring that the current flows from live wire LA, live wire LN, and live wire LC through the short-circuit protection mechanism. B. The input or output of the live wire LC is unaffected. Furthermore, an LED indicator is connected in parallel with the four diodes D as an indication signal. The voltage on the LED indicator is determined by the four diodes D. The voltage of the PN junction on the diode D is related to the current. Therefore, the brighter the LED indicator, the greater the load. The resistor R connected in series with the LED indicator can be used as a current-limiting resistor, which can reduce the consumption of the LED indicator to a certain extent. Each short-circuit protection mechanism is connected in series with a fuse as a fuse element. After a short circuit occurs at the output, each of the three-phase power supplies can be individually blown.

[0029] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A fuse device for short-circuit protection of a three-phase four-wire output in a laboratory, comprising a PCBA circuit board (1), characterized in that: The top of the PCBA circuit board (1) is fitted with a protective box (2), and the protective box (2) has four sets of wire holes (3) on both sides for the live wire LA, live wire LB, live wire LC and neutral wire LN to pass through and out. The PCBA circuit board (1) is provided with three sets of short-circuit protection mechanisms connected to the live wire LA, live wire LB and live wire LC; The short-circuit protection mechanism is connected to the input and output terminals of live wires LA, LB, and LC. The short-circuit protection mechanism includes an LED indicator, a fuse, and a diode group. The diode group consists of four diodes D connected in series. The two groups of diodes have opposite polarities. An LED indicator is connected in parallel to the diode group. A fuse is connected in series to the input terminals of live wires LA, LB, and LC.

2. The fuse device for three-phase four-wire output short-circuit protection in a laboratory according to claim 1, characterized in that: The LED indicator is connected in series with a resistor R.

3. A fuse device for three-phase four-wire output short-circuit protection in a laboratory according to claim 2, characterized in that: The protective box (2) is made of transparent acrylic material.

4. A fuse device for three-phase four-wire output short-circuit protection in a laboratory according to claim 3, characterized in that: The fuse is a time-delay fuse, the rated current of the fuse is 2 amps, and the maximum rated voltage of the fuse is 250 volts.

5. A fuse device for three-phase four-wire output short-circuit protection in a laboratory according to claim 4, characterized in that: The diode D is selected as a rectifier diode.

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