JP2549981B2 - Operation checker for earth leakage circuit breaker with open-phase protection function for single-phase three-wire system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation checker for an earth leakage circuit breaker with an open-phase protection function for a single-phase 3-wire system (hereinafter abbreviated as ELB with open-phase protection), and more particularly to an ELB with open-phase protection.
The operation checker of the ELB with open phase protection used for checking the open phase protection operation of.

[0002]

2. Description of the Related Art Conventionally, a single-phase three-wire type power distribution system has been known. The single-phase three-wire system has two voltage lines L ₁ , L ₂ and 1
Using the neutral line N of the book, each voltage line L ₁ , L ₂ and the neutral line N
And distribution voltage of 100 (V) between the voltage line L _1, L ₂
It is a method of distributing a voltage of 200 (V) between them. Such a single-phase three-wire system is widely used in general houses because it can have a larger capacity than the two-wire system, and the service line 32 of the general house is widely used.
The single-phase three-wire conversion rate has reached 47.1% in Japan as a whole (1992) and 68.0% in the Kansai Electric Power area.

FIG. 5 is a wiring diagram of a single-phase three-wire system. The power distribution terminal 31a of the utility pole 31, which is a facility of the power company, and the power receiving terminal 33 of each home are connected by the service line 32.
3 is connected to the earth leakage breaker 37 of the distribution board 36 via the electricity meter 35 by the inlet wiring 34. The distribution board 36 is provided with a plurality of circuit breakers 38 for wiring, and an appropriate two of the three load side terminals of the earth leakage circuit breaker 37 are connected to the wiring 3.
9 is connected to an outlet in each room and various electric devices via a circuit breaker 38 for wiring. For example, FIG. 6 (a)
, The voltage lines L ₁ and L ₂ have a rated voltage of 200
(V), power consumption 2000 (W) connected to the air conditioner 40, the voltage line L ₁ and the neutral line N are 100 (V), 200
A fluorescent lamp 42 and 1 connected to a (W) television 41 and having a voltage line L ₂ and a neutral line N of 100 (V) and 40 (W).
It is connected to an incandescent light bulb 43 of 00 (V) and 40 (W).

However, in the single-phase three-wire system, when a disconnection or a contact failure occurs in the neutral wire N (such an accident is called a neutral wire open-phase accident), electric equipment for 100 (V) There was a case where an overvoltage was applied to the electric equipment and the electric equipment failed or burned. That is, when the neutral wire N has a missing phase in the wiring diagram shown in FIG. 6A, as shown in FIG.
Is distributed to the parallel body of the fluorescent lamp 42 and the incandescent lamp 43 and the television 41, and 143 (V) is added to the former and 57 (V) is added to the latter. Therefore, the fluorescent lamp 42 and the incandescent lamp 43 are burned out. Each voltage is expressed by the following equation (3)
It is calculated in (4).

200 (V) × 125 (Ω) / [50 (Ω) +125 (Ω)] = 143 (V) (3) 200 (V) × 50 (Ω) / [50 (Ω) +125 (Ω) )] = 57 (V) (4) Therefore, when a neutral wire open phase occurs, the ELB5 with open phase protection has a function of detecting it and shutting off the power supply side and the load side.
0 was developed. FIG. 7 is a block diagram showing the configuration of the ELB 50 with open phase protection. In the ELB 50 with phase loss protection, power source side voltage line terminals 51, 53, and
Power supply side neutral wire terminal 52, load side voltage wire terminal 54, 5
6, a load-side neutral wire terminal 55 and an overvoltage detection lead wire 69 are provided. Power supply side terminals 51, 52, 53
Is connected to the watt-hour meter 35 via the inlet port wiring 34 as shown in FIG. 5, and the load side terminals 54, 55, 56 are the wiring 3
9 is connected to the wiring breaker 38, and the overvoltage detection lead wire 69 is connected to a neutral wire bar (not shown) provided in the distribution board 36.

Further, the power supply side terminals 51, 52, 53 and the load side terminals 54, 55, 56 are connected inside the apparatus through a main switch 58 and an overcurrent preventing bimetal 61. The main switch 58 is manually turned on and off from outside the device (see FIG. 2) and is turned off by the electromagnetic force of the electromagnetic coil 59. An electronic circuit 6 including a leakage detection unit 65 and an overvoltage detection unit 66 in the device
4 is provided, and the electromagnetic coil 59 is driven by the electronic circuit 64. The leakage detecting unit 65 detects the balance between the current flowing to the load side and the current returning to the power source side by the zero current transformer (ZCT) 63, and determines the presence or absence of leakage. When the current balance is lost, it is determined that a leakage has occurred, and the electromagnetic coil 59 is supplied with power to turn off the main switch 58.

The overvoltage detecting section 66 includes a voltage detecting terminal 66.
The voltage V between the terminals a and 66b is a predetermined threshold value V_thGreater than
It is judged that the neutral phase open phase has occurred when
Power is supplied to the coil 59 to turn off the main switch 58.
More specifically, the voltage detection terminal 66a is connected to the diode.
Diode connected to the cathode of
The anodes of 67 and 68 are load side voltage line terminals 54 and 56.
It is connected to the. On the other hand, the voltage detection terminal 66b is
It is connected to the voltage detection lead wire 69. Therefore,
Between the voltage detection terminals 66a and 66b, as shown in FIG.
To the voltage line L₁, L ₂AC voltage v₁, V₂Half-wave rectification
DC voltage V₁, V₂Appear alternately. When normal
DC voltage V₁And DC voltage V₂Are equal to each other, but neutral
When the open phase occurs, for example, the DC voltage V₁Is big
DC voltage V₂Becomes smaller. Overvoltage detector 6
6 is a DC voltage V₁Is the threshold V_thNeutral when crossed
Judge that the open phase has occurred.

The earth leakage display button 60 is interlocked with the main switch 58 of the electromagnetic relay 58, and the main switch 5
It projects when 8 is turned off. Also, the test button 62
Is for checking whether the leakage detection function is normal.

[0009]

According to the manufacturer, the useful life of such an ELB50 with open phase protection is about 10 years, but the conventional ELB50 with open phase protection is provided with a function for checking the open phase protection function. There was no measuring instrument for checking the open-phase protection function in the field.
Therefore, the leakage function can be checked during the periodic inspection, but the open-phase protection function cannot be checked. ELB5 with open-phase protection that exceeds its useful life
When 0 was opened and a power failure occurred, it was impossible to determine whether the neutral wire open phase actually occurred or the ELB 50 with open phase protection failed, and it took time to investigate the cause of the power failure.

Therefore, a main object of the present invention is to provide an operation checker for an ELB with open phase protection, which can easily check the open phase protection function of the ELB with open phase protection on site.

[0011]

According to the present invention, there are provided an overvoltage detection lead wire and a load side neutral wire terminal connected to a load side neutral wire, and two load sides each connected to a load side voltage wire. A single-phase 3 that includes a voltage line terminal and shuts off the power supply side and the load side when the voltage between any one of the load side voltage line terminals and the overvoltage detection lead wire exceeds a predetermined voltage. In an operation checker of an earth leakage circuit breaker with a wire-type open phase protection function, the operation checker includes two fixed terminals and a sliding terminal movably provided on a resistor between the fixed terminals, each of the fixed terminals including the load. Connected to the terminal for the side voltage line,
The sliding terminal includes a variable resistor connected to the overvoltage detection lead wire removed from the load-side neutral wire, and a current limiting resistor for limiting a current flowing through the variable resistor. Is characterized by.

Further, a voltmeter for measuring a voltage between any one of the two load side voltage line terminals and the overvoltage detection lead wire removed from the load side neutral line may be provided. Good.

A changeover switch may be provided for switching and connecting the voltage measuring terminal of the voltmeter to one of the two load side voltage line terminals.

A detection switch may be provided for connecting the sliding terminal of the variable resistor and the overvoltage detection lead wire removed from the load-side neutral wire.

Further, a timer may be provided for measuring the time from turning on of the detection switch to opening of the earth leakage circuit breaker with a single-phase three-wire type open-phase protection function.

[0016]

The operation checker of the ELB with phase loss protection according to the present invention is provided with the variable resistor including two fixed terminals and sliding terminals movably provided on the resistor between them. The fixed terminal of the variable resistor is connected to the load side voltage wire terminal of the ELB with open phase protection, and the sliding terminal is connected to the overvoltage detection lead wire removed from the load side neutral wire. If the sliding terminal of the variable resistor is placed in the middle of the two fixed terminals, it will be 100 between the sliding terminal and each fixed terminal.
A voltage of (V) is applied. Next, when the sliding terminal is brought closer to one of the fixed terminals, the voltage between the fixed terminal and the sliding terminal becomes less than 100 (V), and the voltage between the other fixed terminal and the sliding terminal becomes 100. It becomes larger than (V). Then, when the voltage between the other fixed terminal and the sliding terminal exceeds the predetermined voltage, the ELB with open phase protection is opened if the open phase protection function is normal. Therefore, E with open-phase protection
The open phase protection function of the LB can be easily checked on site.

Further, since the current flowing through the variable resistor is limited by the current limiting resistor, even if the sliding terminal of the variable resistor is brought close to one of the fixed terminals, the overcurrent may cause the variable resistor to burn out. Absent.

[0018]

1 is an electric circuit diagram showing the configuration and usage of an operation checker 1 for an ELB with phase loss protection according to an embodiment of the present invention, and FIG. 2 is a front view showing its appearance and usage. In this operation checker 1, for example, an overvoltage lead wire terminal 2, voltage wire terminals 3 and 4, a detection switch 5, a power switch 6 are provided on one surface of a rectangular parallelepiped case 1a.
Display panel of voltmeter 11, voltmeter selector switch 10, dial 9a of variable resistor 9 and recorder terminals 12, 13
Is provided. Power switch 6 is two switches 6
The interlock switch includes a and 6b.

In the case 1a, the voltage line terminals 3 and 4 are the switches 6a and 6b of the power switch 6, the fuses 7 and 7, the connection nodes N1 and N2, the current limiting resistors 8 and 6, respectively.
8 is connected to the fixed terminals 9a and 9b of the variable resistor 9, and the overvoltage lead wire terminal 2 is connected to the sliding terminal 9c of the variable resistor 9 via the detection switch 5.
Further, the voltage measuring terminals 11a and 11b of the voltmeter 11 are connected to the recorder terminals 12 and 13, respectively, the terminal 11a is connected to the sliding terminal 9c of the variable resistor 9, and the terminal 11b is a voltmeter changeover switch. Connection node N by 10
1 or the connection node N2 is switched and connected.

The circuit breaker 38 for wiring shown in FIG.
Are all turned off, the main switch 58 of the ELB 50 with open phase protection is also turned off, and the overvoltage detection lead wire 69 is removed from the neutral wire bar. After confirming that the switches 5 and 6 of the operation checker 1 are off and the dial 9d of the variable resistor 9 is positioned in the middle, as shown in FIG. Lead wires 14, 15 and 16 for detecting the overvoltage of the ELB 50 with open phase protection 69,
It is connected to the load side voltage line terminals 54 and 56.

Next, the mains of the ELB50 with phase loss protection
Switch 58 is turned on and 2 is applied to terminals 3 and 4 of operation checker 1.
Apply a voltage of 00 (V) and turn on the power switch 6.
You. At this time, set the dial 9d of the variable resistor 9 to the middle position.
Since it is placed, the voltage v between terminals 3 and 2₃₂And terminal 4,
Voltage v between two₄₂Are both 100 (V). Sanawa
Then, as shown in FIG. 3A, the resistance value of the current limiting resistor 8
Is R [for example, 10 k (Ω). ], Variable resistor
The resistance value between the fixed terminal 9a of 9 and the sliding terminal 9c is R ₁,
The resistance value between the fixed terminal 9b and the sliding terminal 9c is R₂[However
Then R₁+ R₂= R _CIs constant, for example, 15k
(Ω). ], The voltage v₃₂, V₄₂Is
It is represented by (1) and (2).

V₃₂= 200 (R + R₁) / (2R + R_C)… (1) v₄₂= 200 (R + R₂) / (2R + R_C) (2) In the state of FIG. 3 (a), in the above equations (1) and (2)
R₁= R₂= 1 / 2R _CTherefore v₃₂= V₄₂= 100
(V). Alternating voltmeter changeover switch 10
Confirm that the indicated value of the voltmeter 11 does not change.
Ku.

Next, for example, the voltmeter changeover switch 10
To the connection node N1 side, and gradually turning the dial 9d of the variable resistor 9 as shown in FIG.
The resistance value R ₁ between the fixed terminal 9a and the sliding terminal 9c is increased. When the resistance value R ₁ is increased, the voltage v ₃₂ increases and the voltage v ₄₂ decreases as can be seen from the above equations (1) and (2). Then, when the voltage v ₃₂ is a predetermined threshold value v _th [(for example, 130 (V). R ₁ = 13 k (Ω), v ₃₂ = 1.
It becomes 31 (V). ], The ELB with open-phase protection
If 50 is normal, ELB50 with open phase protection is opened,
The indicated value of the voltmeter 11 becomes 0 (V). If other checks are also performed and it is determined that the ELB 50 with phase loss protection is normal, the lead wires 14, 15 and 16 are removed, the lead wire 69 for overvoltage detection is attached to the neutral wire bar, and the ELB with phase loss protection is attached.
The inspection is completed by returning B50 and the wiring breaker 38. On the other hand, if the open phase protection ELB50 does not open even when the voltage v ₃₂ exceeds the threshold value v _th , the open phase protection ELB5
0 is judged to be damaged and replaced with a good product. Even if the ELB 50 with open-phase protection is opened, the voltage v
_{When 32} greatly exceeds the threshold value v _th , it is determined that the ELB 50 with open phase protection is deteriorated, and the ELB 50 is replaced with a good product.

As the voltmeter 11, the measured voltage is 0.
The threshold value V _th can be easily read by using a device having a function of holding the maximum value of the measured voltage even after the voltage reaches (V) (for example, a device in which the pointer is stopped while indicating the maximum voltage). You can

FIG. 4 is an electric circuit diagram showing the configuration and usage of an operation checker 20 of an ELB with open phase protection according to another embodiment of the present invention. In addition to the configuration of the operation checker 1 shown in FIG. 1, the operation checker 20 has a voltage V
A timer 17 is provided for measuring the reaction time T _th from when ₃₂ reaches the threshold value v _th until the ELB 50 with open phase protection is opened. Further, an interlocking switch including two switches 5a and 5b is used as the detection switch 5, one switch 5b is connected between the overvoltage lead wire terminal 2 and the sliding terminal 9c, and the other switch 5a.
Is connected between the start terminals 17a, 17a of the timer 17. Also, an electromagnetic relay 18 is provided,
The N. C. (Normally closed) Switch 18a uses timer 17
And the electromagnetic coil 18b is connected to the connection nodes N1 and N2.

However, when the voltage v ₃₂ exceeds the threshold value v _th by the same procedure as in the above embodiment, the ELB with open phase protection is provided.
Make sure 50 is open. Next, timer 17
Reset, turn off the detection switch 5, E
The main switch 58 of the LB 50 is turned on. As a result, power is supplied to the electromagnetic coil 18b of the electromagnetic relay 18, and the N.V.
C. The switch 18a turns off. Next, when the detection switch 5 is turned on, the start terminal 17a of the timer 17,
17a is short-circuited and the timer 17 starts. After that, when the ELB 50 with open phase protection is opened, the power supply to the electromagnetic coil 18b of the electromagnetic relay 18 is stopped and the N.P. C. The switch 18a turns on, and the stop terminal 1 of the timer 17
7b and 17b are short-circuited and the timer 17 stops. If the instruction value of the timer 17, that is, the reaction time T _th, is within the standard, the inspection is ended, and if it is out of the standard, the phase loss protection E
LB50 is judged to have deteriorated and replaced with a good product.

[0027]

As described above, according to the present invention, the sliding terminal and the fixed terminal of the variable resistor are connected to the overvoltage detection lead wire and the load side voltage wire terminal of the ELB with open-phase protection, and the variable resistance is changed. E with phase loss protection by simply changing the resistance value of the resistor
It is possible to check the open phase protection function of the LB. Therefore, the open phase protection function of the ELB with open phase protection can be easily checked on site. For example, it is convenient because the open-phase protection function can be easily checked during periodic inspections. In addition, when the ELB with open-phase protection that has exceeded its service life is opened and a power failure occurs, it is possible to easily check whether a neutral wire open-phase accident has occurred or the ELB with open-phase protection has broken down. The cause of can be investigated promptly.

Further, since the current limiting resistor is provided, the variable resistor is not burned by the overcurrent.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram showing a configuration and a usage state of an operation checker of an ELB with open phase protection according to an embodiment of the present invention.

FIG. 2 is a front view showing an appearance and a usage state of an operation checker of the ELB with open phase protection shown in FIG.

3 is an electric circuit diagram for explaining an operation of an operation checker of the ELB with open phase protection shown in FIG.

FIG. 4 is an ELB with open-phase protection according to another embodiment of the present invention.
3 is an electric circuit diagram showing the configuration and usage state of the operation checker of FIG.

FIG. 5 is a wiring diagram of a single-phase three-wire system in a general house.

FIG. 6 is a wiring diagram for explaining the defects of the single-phase three-wire system.

FIG. 7 is a block diagram showing a configuration of an ELB with phase loss protection.

FIG. 8 is a waveform diagram for explaining the operation of the ELB with open phase protection shown in FIG. 7.

[Explanation of symbols]

1 Operation checker 8 Current limiting resistor 9 Variable resistor 9a, 9b Fixed terminal 9c Sliding terminal 50 ELB with open phase protection 54, 56 Load side voltage wire terminal 55 Load side neutral wire terminal 69 Overvoltage detection lead wire L ₁ , L ₂ voltage line N neutral line

Claims (5)

(57) [Claims] 1. An overvoltage detection lead wire and a load-side neutral wire terminal connected to the load-side neutral wire, and two load-side voltage wire terminals each connected to the load-side voltage wire. , A single-phase three-wire open-phase protection function that shuts off the power supply side and the load side when the voltage between any one of the load side voltage line terminals and the overvoltage detection lead wire exceeds a predetermined voltage. An operation checker for an earth leakage circuit breaker includes two fixed terminals and a sliding terminal movably provided on a resistor between the fixed terminals, the fixed terminals being respectively connected to the load side voltage line terminals. The sliding terminal includes a variable resistor connected to the overvoltage detection lead wire removed from the load-side neutral wire, and a current limiting resistor for limiting a current flowing through the variable resistor. Phase breakage for single-phase three-wire system characterized by Mamoru behavior checker function with earth leakage circuit breaker. 2. A voltmeter for measuring a voltage between any one of the two load side voltage line terminals and the overvoltage detection lead wire removed from the load side neutral line. The operation checker for an earth leakage circuit breaker with a single-phase, three-wire system open-circuit protection function according to claim 1. 3. The switch according to claim 2, further comprising a changeover switch for changing over and connecting the voltage measuring terminal of the voltmeter to one of the two load side voltage line terminals. Operation checker of the earth leakage circuit breaker with the open-phase protection function for the single-phase three-wire system. 4. A detection switch for connecting a sliding terminal of the variable resistor to the overvoltage detection lead wire removed from the load-side neutral wire. An operation checker for an earth leakage circuit breaker with a single-phase, three-wire type open-phase protection function according to any one of 1 to 3. 5. A timer is provided for measuring the time from when the detection switch is turned on to when the earth leakage breaker with a single-phase, three-wire type open-circuit protection function is opened. An operation checker for an earth leakage circuit breaker with a single-phase, three-wire system open-phase protection function according to claim 4.