JPH0350464Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an open phase display device that displays an open phase in a three-phase power supply.

[Prior Art] Conventionally, devices for detecting a phase failure in a three-phase power supply and protecting control equipment have had a complicated configuration. Additionally, overload relays and the like are used to protect control equipment. In the conventional open-phase display device, a single neon lamp 30 is connected between two phases R and T among the three phases R, S, and T to indicate the interruption of the power supply, as shown in Fig. 3. ing.

[Problems to be solved by the invention] However, in the conventional open-phase display device, for example, when the S phase is open, the neon lamp 3
Even though 0 is on, the overload relay is activated, so the customer does not realize that the S phase is open, and it takes time to find another cause and take time to repair it. In addition, when a transformer is connected between the S phase and the T phase to supply power to an operating circuit, etc., there is a problem in that the user does not realize that there is an open phase and it takes time to repair it. Ta.

The present invention has been made to solve the above problems, and provides an open-phase display device that easily displays three-phase open-phase states, including open-phase states of the power supply to operating circuits, etc., with a simple configuration. The purpose is to provide.

[Means for Solving the Problems] In order to achieve the above object, the present invention connects a transformer between two phases of a three-phase power supply, connects an indicator light to the transformer, and connects a transformer to the transformer. A high resistance indicator lamp is connected between one of the two phases connected to the transformer and the phase not connected to the transformer.

[Operation] According to the present invention, a transformer is connected between two phases of a three-phase power source, and an indicator light is connected to the transformer. Also, since a high-resistance indicator light is connected between one phase connected to the transformer and a phase not connected to the transformer, the phase that supplies power to the operating circuit, etc. should also be considered. The open phase status of three phases can be accurately indicated on the indicator light and high resistance indicator light.

[Example] Hereinafter, an example of an open phase display device according to the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a circuit diagram of a first embodiment of an open phase display device according to the present invention.

A neon lamp 10, which is a high resistance indicator light, is connected between the R phase and the S phase. In addition, between the S phase and the T phase, there is a
Secondary coil 12A, secondary coil 12B and iron core 1
The primary coil 12A of the transformer 12 with 2C is connected. The primary coil 12 of this transformer 12
A conducting wire 14 connected to an operation circuit (not shown) is connected in the middle of A, and this conducting wire 14 and T
A neon lamp 16, which is an indicator light, is connected between the phase and the phase. Note that the indicator light may be a low-resistance lamp instead of a high-resistance lamp such as a neon lamp. In addition, a conductor 18 connected to the operating circuit is connected to the T phase.
is connected. The three phases R, S, and T are connected to a power circuit for driving a motor or the like.

The operation of the first embodiment configured as above will be explained. If the R phase is open, no voltage is applied to the R phase, so the neon lamp 10
The voltage applied to the neon lamp 10 becomes lower than the discharge voltage and the neon lamp 10 goes out. Then, the S-phase voltage is applied to the conducting wire 14 via the primary coil 12A of the transformer 12. Further, since voltage is applied to the T phase, the neon lamp 16 is lit.

In addition, when the S phase is open, the voltage of the R phase is transferred to the conductor 1 via the neon lamp 10 and the transformer 12.
4. Also, since voltage is applied to the T phase, neon lamps 10 and 16
Both are dimly lit. In addition, in this case, transformer 1
If the impedance of 2 is increased, the voltage applied to the neon lamps 10 and 16 becomes lower than the discharge voltage, and both neon lamps 16 are turned off, making it possible to clearly indicate an open phase.

Further, when the T phase is open, no voltage is applied to the T phase, so the voltage applied to the neon lamp 10 becomes equal to or less than the discharge voltage, and the neon lamp 16 is turned off. Since voltage is applied to the R phase and the S phase, the neon lamp 10 lights up.

Next, a second embodiment of the open phase display device according to the present invention will be described using FIG. 2.

A neon lamp 20, which is a high resistance indicator light, is connected between the R phase and the S phase. A primary coil 22A of a transformer 22 for supplying power to the operating circuit is connected between the S phase and the T phase. Conductive wires 24 and 26 are connected from the secondary coil 22B of the transformer 22 to an operation circuit (not shown), and a neon lamp 28 as an indicator light is connected between the conductive wire 24 and the conductive wire 26. ing. Note that the indicator light may be a low-resistance lamp instead of a high-resistance lamp such as a neon lamp. In addition, three-phase R, S,
T is connected to a power circuit for driving a motor or the like.

The operation of the second embodiment configured as above will be explained. When the R phase is open, no voltage is applied to the R phase, so the voltage applied to the neon lamp 20 becomes equal to or lower than the discharge voltage, and the neon lamp 20 turns off. The voltage of the S phase and the voltage of the T phase are transmitted through a transformer 22 to a conductor 24 and a conductor 26.
is applied to Therefore, the neon lamp 28 is lit.

Further, when the S phase is open, no voltage is applied to the S phase, so the voltage applied to the neon lamp 20 becomes equal to or lower than the discharge voltage, and the neon lamp 20 goes out. The T-phase voltage is applied to the conducting wire 24 and the conducting wire 26 via the transformer 22. Therefore, the neon lamp 28 is dimly lit. In this case, if the impedance of the transformer 22 is increased, the voltage applied to the neon lamp 28 becomes lower than the discharge voltage, the neon lamp 28 is turned off, and the open phase can be clearly displayed.

In addition, when the T phase is open, the R phase and S
Since voltage is applied to the phase, the neon lamp 20
lights up. Furthermore, although the S-phase voltage is applied to the transformer 22, it is not applied to the conducting wires 24 and 26 because the impedance of the transformer 22 is large. Therefore, the neon lamp 28 is turned off.

As described above, when an open phase occurs in consideration of the power supply for the operating circuit, an indication of the open phase can be displayed on the neon lamp, making it easy to discover the cause of the failure and repair it.

[Effect of the invention] As explained above, according to the invention, the indicator light and high resistance indicator light are turned on when there is no open phase in all three phases, and the indicator light is turned on when even one phase is open. Alternatively, one or both of the high-resistance indicator lights are turned off, making it possible to accurately indicate an open phase state. Furthermore, since the phase that supplies power to the operating circuit, etc., is also taken into account, the cause of the failure can be easily discovered and repaired. This effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a first embodiment of an open-phase display device according to the present invention, FIG. 2 is a circuit diagram showing a second embodiment of an open-phase display device according to the present invention, and FIG. 3 is a circuit diagram showing a conventional open-phase display device. FIG. 10, 16...Neon lamp, 12...Transformer.

Claims (1)

[Scope of utility model registration request] A transformer is connected between two phases of the three-phase power supply, an indicator light is connected to the transformer, and one phase of the two phases connected to the transformer is connected to the transformer. An open-phase display device characterized by connecting a high-resistance indicator light between the open phase and the open phase.