JP2002034109A - Branch circuit system from single-phase three-wire main line - Google Patents

Abstract

PROBLEM TO BE SOLVED: To double the power density of each breaker of each branch circuit from a single-phase three-wire main line and to make it of the same level as 200 V wiring, by making possible the wiring of both voltages of 100 V and 200 V to each breaker, without causing the phase failure or a neutral conductor. SOLUTION: Two branch circuits of 100 V are taken from the single-phase three-wire main line for each breaker of two poles and two elements, and the return wire of each circuit is connected to a neutral phase with a terminal removable individually, with a 200 V circuit which can be taken between the active phases of the two branch circuits. Also, the terminal is arranged, by displacing it in the direction of line core or a group of the terminals are arranged, dividing them into groups for each phase of the branch circuits, so that the conductor of the line ends is not brought into contact each other, when the return wire is removed for inspections and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a branch circuit in a place where electricity is used for single-phase three-phase power distribution.

[0002]

2. Description of the Related Art Conventionally, small consumers such as offices and houses were initially distributed with a single phase of 100 V. However, recently, with the electrification and capacity increase of cooling / heating, office / kitchen appliances,
The adoption and implementation of 100 / 200V single-phase three-wire power distribution to adopt the same rated voltage as Europe and the United States.
Each of a 00V high load device and a 100V low load device group is branched by a circuit breaker, and each branch circuit is provided with a single-phase two-wire indoor wiring using a two-core cable.

In general, a 200V branch circuit is rated at 220 / 110V with two poles and two elements, and a 100V circuit is one with two poles and one element.
Short circuit and overload protection are performed with a 10V rated circuit breaker. The maximum power used by a circuit breaker with a rated current of 20A is 4KW for a 200V circuit and 2KW for a 100V circuit. The dimensions are the same.

[0004]

Recently, with the upsizing of offices and houses and the increase of electrical equipment, the installed capacity of the equipment has increased and the number of breakers in the branch circuit of the distribution board has increased. Because a circuit breaker is added as a separate circuit wiring, a plurality of distribution boards may be installed, and the cost and space for the installation place are increased.

Of course, the 110/2 branch circuit also requires
If a single-phase three-wire system is wired using a circuit breaker rated at 20V, the capacity can be increased to 2KW and a total of 4KW can be used for each phase, and both voltages can be used. If the neutral wire breaks or the terminal loosens, the contact failure, derailment, etc. may occur, or the breaker may be accidentally turned on during inspection or removal.
The voltage imbalance between the phases due to the open phase of the neutral wire leads to an accident such as burnout or disconnection of the terminal equipment.
According to Article 71, Paragraph 1, Item 8 ", wiring other than a single dedicated dual-voltage device wiring is prohibited.

According to the present invention, the method of connecting the neutral circuit of the branch circuit to the neutral phase is improved so that the above-mentioned neutral phase loss does not occur, and the maximum load of the 100 V branch circuit is reduced by 2 with the same rated current circuit breaker.
100 V circuit and double the number of branch circuits for each circuit breaker by 100
Both voltages of / 200V can be used.

[0007]

In order to achieve the above object, according to the present invention, a two-pole two-element 110/220 is used.
Branched from the mains of single-phase three-wire power distribution with a V-rated circuit breaker, and both active phases are separated into 100V2 circuits with separate two-core cables.
Wire-type wiring is performed, the ground-side return lines are individually connected to the neutral phase, and a 200V1 circuit is used between both active phases.

The connection to the neutral phase is made by a separate terminal for the return line of each phase circuit, and can be easily removed and reconnected at the time of inspection such as insulation measurement. When the terminal is removed from the terminal, the return line is connected. In order to prevent the end conductor portion from accidentally contacting the line end conductor portion of the other phase circuit return line, the end conductor portion is shifted in the wire core direction or is arranged separately from the terminal group of the other phase circuit return line.

In each circuit, a wire core or a wire pair has an active phase by color (for example, red / blue) and a circuit breaker number (for example, 1, 2, 3).
・ ・ ・ ・ ・ Attach the insulated marker marked or printed, and insulate the insulation color of the wire core of each circuit (black for 2 cores: live wire ・ white:
The circuit is clearly identified in conjunction with (return).

[0010] The marker is printed by the printed character color of the circuit breaker number or the circuit breaker number and the phase symbol (for example, U, V or R,
It may be printed in combination with S).

For the wiring of the 100V branch circuit of both phases, considering the cable cores of the same color (black and white) for both circuits, it is preferable to use a separate electric circuit separately from the junction box. If the cables of both circuits must be passed, relayed, and connected to the same connection box due to the mixing arrangement, etc., the above-mentioned color-coded markers should be applied or a 4-core cable (red / white) And black and green are divided into both circuits, and red and black are live lines, white and green are return lines), so that a single-phase three-wire connection is not mistakenly confused with the ground-side return line of the two-phase circuit. , Complete identification and independence.

The two circuits for each circuit breaker are arranged in parallel to the place of use. Wiring is made to a 100 V load from a connection box arranged at an easy-to-operate location such as a ceiling inspection port. If necessary, both active phases are connected in the connection box. It is preferable to connect and wire a 200 V circuit to the wire core, and when the equipment installation location is adjacent to or close to the distribution board, the 200 V circuit may be directly connected to both active phase terminals of the circuit breaker ( The breaker terminal can connect two wires.)

[0013]

The operation of the branch circuit according to the present invention constructed as described above will be described. Even if there is a disconnection of the return line on the ground side of each circuit or a loose terminal of the neutral phase, a contact failure or derailment occurs. Only the current of the circuit is cut off, the other circuit is alive, and
In both circuits, even if there is a disconnection on the ground side return line or a loose terminal,
Only the current of both circuits is cut off apart from the neutral phase, there is no contact between the return wires, and no accident such as neutral phase loss of single-phase three-wire wiring occurs.

During circuit insulation measurement and inspection, if the circuit breaker of the circuit is accidentally turned on with the ground return of both circuits removed from the neutral phase, or the circuit breaker remains "on" Even if the return wire is accidentally removed, the return terminal of the neutral phase is shifted in the wire core direction or the return wire group is divided according to the branch phase. There is no fear of a neutral line loss accident.

Even if there is a 200V device connected between both active phases of the above-mentioned two branch circuits, the above-mentioned disconnection / derailment or erroneous operation at each return of the 100V circuit will interrupt the current of the 100V circuit. Alone did not result in a neutral phase loss accident,
There is no effect on the V circuit, and if any one of the live wires breaks or is disconnected from the breaker terminal, it will be connected to the other live wire at a voltage of 100 V in the same manner as the single-phase three-wire wiring. Between the sexual phase, the 200V device and the 100V device on the disconnection / derailment side are connected in series. However, the voltage is proportional to the inverse ratio of the impedance of both devices and 100V, which is low and does not lead to failures such as burnout or disconnection. There is no problem because it can be detected early due to inoperability or functional deterioration.

[0016] The circuit breaker number,
Phase distinction and live / return lines can be clearly identified.
In the circuit, the marker may be attached to the core of the cable.

[0017]

Embodiment 1 As an embodiment 1 of the present invention, a single-phase three-wire 100
A description will be given of a case where power is received at / 200V, and a 3-pole 2-element earth leakage breaker is provided as a drop-in switch and eight wiring breakers are provided as branch circuit breakers on a distribution board near a drop-in point.

In FIGS. 1A and 1B, the distribution transformer 1
A 100 / 200V single-phase 3-wire distribution line 3 with a class B grounding 2 at the secondary neutral point is used as the main line, and the load of a drop switch 5 (circuit breaker with earth leakage protection) of a distribution board 4 The active phase bus 6 (R, S) and the neutral phase bus 7 (N) are arranged on the side, and the power supply side terminal 10 of each branch circuit breaker 8 (# 1, # 2, # 3 ...) is connected. The load side terminal 1 is connected to the active phase bus 6 (R, S) by the conductor 9.
1 (U, V) to the active phase core 13 (U,
V), and the return wire 1 on the ground side of the cable 12
4 terminals 15 arranged in a zigzag pattern on neutral phase bus 7 (N)
(Nu, Nv), 100 V2 circuits (U-Nu, V-Nv) and 200 V1 circuit (U-V) for each breaker 8
Is formed.

In each 100 V circuit, low-load equipment such as a lighting fixture 16 (a switch is not shown) and a general-purpose outlet 17 are sorted so that the load is equally divided into both active phases as much as possible.
The high voltage equipment outlets 18 such as an air conditioner and a heater are connected to the 00V circuit.

The 200 V outlet 18 has a ground voltage of 1
Because it is 00V, grounding is not necessary in a dry room.
9 and a ground wire 20 are connected to the ground pole of the outlet.

In each circuit breaker 8, if the subtotal load of each 100V circuit is P1 and the subtotal load of the 200V circuit is P2, the loads Pu and Pv of each phase U and V will be P1 + P2, respectively.
/ 2, total load ΔP = Pu + Pv = 2 × P1 + P2, and when the rated current I of the circuit breaker 4 is 20A, each phase U,
The maximum allowable load Pa of V is 2 KW, that is, ΔPa =
4 KW.

An insulation sleeve 21 is provided at the wire end of the ground side return wire 14 of each 100 V circuit, and its terminal 15 (Nu, Nv
) Are displaced in the direction of the wire core 14 and are tied and restrained to the active phase wire core 13 connected to the terminal 11 of the circuit breaker 8. If there is no danger that the conductor portion 22 may accidentally come into contact with an adjacent one, that is, a common neutral line, and even if the breaker 8 is accidentally turned on, no current flows in each 100V circuit, and the neutral line open phase No accidents occur.

Each active phase (U, V) and return wire core 13,
For each pair of 14 (U · Nu, V · Nv), a colored insulation marker 23 (red / blue) printed with a circuit breaker number is applied, and the wire core is colored (black / white, 4-core for a 2-core cable). Red cable
(White, black / green) to identify circuits and phases.

In the drawings, for the sake of illustration, the phase identification of the marker is indicated by the phase symbols U and V and together with the circuit breaker number, for example, “1U, 2U, 3U, 4U.
, 3V, 4V,... ”, The red color for the U-phase circuit, the blue color for the V-phase circuit, and the circuit breaker numbers“ 1, 2,.
It is easy to print only “3, 4,...”, Or the phase symbols U, V and color coding (red, blue) may be used in combination. Just kind.

Instead of arranging the terminals 15 of the above-mentioned ground side return line 14 in a staggered manner, they are arranged in the same column as shown in FIG. 2A, and the wire cores 14 and 15 of each circuit are slanted (for example, α = 45
), And may be fixed together with the live wire 14 connected to the terminal 11 of the circuit breaker 8, and the terminal 15 is separated from the wire cores 13, 14 at the interval p (17 mm for a circuit breaker rated at 20 A).
Tan α (0.71 × p = 12 mm), and when the return wire 14 is removed at the time of circuit inspection, there is no possibility that the line end conductor portion 22 comes into contact with an adjacent one.

As shown in FIG. 2B, the terminal 15 of the return line 14 is divided into neutral phase buses 7 (Nu and N
v) may be arranged. In this case, since the live line 13 and the return line 14 of each circuit are separated from each other, a marker 23 for each color is applied to both cores.

[0027]

Embodiment 2 In the double branch circuit described with reference to FIG. 1, a wiring method of a 200 V circuit will be described as Embodiment 2 with reference to FIG.
Insert the wire core 26 (black, white) of the V circuit cable 25 into the circuit breaker 8
And the load side terminals 11 (U, V) are directly connected together with the wire core 13 of the cable 12 of the 100 V circuit. It should be applied when it is easy.

In FIG. 3 (b), in a place where the work is easy, such as a wiring inspection port near the installation location of the load equipment, a 100V2
The cable 12 of the circuit is cut in the middle, the wire ends are processed in the connection box 24, and the wire core 26 (black: U, white: V) of the cable 25 of the 200V circuit is color-coded on the live line 13 (black). This shows a general case where a connection is made by attaching a marker 23 (for example, 2U, 2V).

In FIG. 3 (c), 4
The core cable 27 is used, and the wire core 28 (red / white) is used for the U-phase circuit (U · Nu), and the wire core 28 (black / green) is used for the V-phase circuit (V · Nv). Similarly to the above, the case where the wire cores 26 (U, V) of the cable 25 of the 200 V circuit are connected is shown, and it is preferable to apply the present invention to the simultaneous construction of both voltage circuits and the case where the future addition of the 200 V device is clear.

In any of the above, of course, both voltage circuits are simultaneously installed, and at the moment, a 100 V2 circuit is installed.
A 0V circuit can be easily added without any modification or expansion such as addition / replacement of a circuit breaker of a distribution board, and difficult cable wiring work.

[0031]

According to the branch circuit system of the present invention, one circuit breaker can open / close two circuits with a rated voltage of 100 V and one circuit with a rated voltage of 200 V, and protect the wiring, and at the same rated current (for example, 20 A). Maximum power similar to 200V distribution (for example, 4K
W), the number of circuit breakers in the distribution board can be halved, that is, the power density can be doubled, and as an advantage of single-phase three-wire power distribution, the size of the distribution board is not limited to the conventional 200V equipment. It can be expanded to save the number, space and cost of installation.

For example, one circuit breaker (20A) is provided for each large room or every two small rooms, and the both-voltage wiring of the present invention is provided.
One circuit for the air conditioner (maximum power consumption P2 = 1.5 to 2K)
W) outlets for each room, 100V
An electric lamp and a household outlet can be arranged in one circuit, and an air conditioner (maximum power consumption of about 1 kW) can be installed. In that case, the total load per 100V circuit is, in addition to the air conditioner,
P1 = 1.25 to 1KW (= 2KW-1/2 of Aircon) in the large room, 1KW (= 2KW-Aircon) in each small room
In general, the maximum load per circuit breaker ΣPa = 4K, depending on the type and capacity of equipment used in each room
Within W, both voltage devices can be used.

For such a load, the conventional branch circuit method uses two 110V rated and 110/22
Although a single 0 V rating and a 110 V rating are used in each compartment, a total of five circuit breakers are used.
A / 220V rated circuit breaker will suffice, and in both cases the circuit breakers have the same external dimensions, so the space reduction effect is large.

Compared to the conventional branch circuit system, each 100V circuit has two circuits connected to each phase of one circuit breaker. Even if a high-load device becomes overloaded when a 100V device is added, it will be half a 200V device. Because the current can be added, the 200V circuit shares most of the live lines of the two-phase 100V circuit and does not require wiring from another circuit breaker. May be.

The 100V circuit has two active phases (R,
Since the load is separated in S) and the 200 V circuit directly loads both active phases, load equalization at the entrance is easy.

Since a branch circuit wiring of both voltages can be provided for each circuit breaker, a circuit of 100/200 V can be wired in all the rooms where electricity is used, and a 200 V circuit can be easily provided near the installation place of the load equipment as required. Additional installation is possible, and the above-mentioned wiring extension and load equalization are combined, which is very convenient in designing and constructing indoor wiring.

In addition, since the 200 V circuit can be easily wired in addition to the 100 V circuit in all the rooms, the low voltage rating of electric lamps, small household appliances, etc. maintains the 100 V rating which is easy to manufacture and use, and which is advantageous for safety and durability. Beside, high-load equipment with a maximum power consumption of approximately 1KW or higher, such as air conditioners, heaters and other cooling / heating equipment, rice cookers, water heaters, microwave ovens, kitchen equipment such as oven toasters, and office equipment such as copiers. Large fluorescent lamps with voltage circuits can be easily transitioned to the 200V rating of the United States and Europe, and the branch circuit system of the present invention promotes the spread of single-phase three-wire power distribution and the unification of international standards for electrical equipment to the 200V class. It is also very convenient in industry.

The 2-pole 2-element 110/220 V rated circuit breaker can be used for a single-phase 3-wire main line, and each pole has short-circuit and overload protection performance of 2 poles / 1 element 110 V rated. Since there is no problem with the combined use of the 100V2 circuit and the 200V1 circuit of the present invention,
The “Electrical Equipment Technical Standards” stipulates that a neutral-phase switch can be omitted as a breaker in each branch circuit if there is a three-pole break-in switch in the distribution board (Article 171-1) No. 2) and the branch power of each breaker is 200
If it is at the same level as that of V class distribution, circuit division and maintenance
There is no problem in inspection, and even in small customers, with the increase in installed capacity, the branch power density for each breaker should be doubled and the economic efficiency should be improved. The method of connecting each circuit to the neutral phase of the return line has been improved to prevent the occurrence of the neutral phase loss accident which is a problem in Article 171 (1), item (8). It is a solution to the problem.

The circuit identification is important and indispensable because of the combined branch circuit wiring of both voltages for each breaker. This is because the circuit is used for reliable construction, maintenance / inspection, and later expansion. It is an indispensable matter in the whole electric work including the circuit system of the above.

The present invention is naturally applicable not only to 100 V / 200 V, but also to branch circuits from single-phase three-wire trunks of different voltages such as 115/230 V.

[Brief description of the drawings]

FIG. 1 is a wiring diagram of a branch circuit according to the present invention, in which (a) is an electric circuit diagram, and (b) is a connection diagram of a wiring breaker in a distribution board, in which return terminals are arranged in a staggered manner. Show the case.

FIG. 2 is a wiring diagram showing a wiring breaker in a distribution board;
(A) shows the case where the wiring is provided diagonally, and (b) shows the case where the neutral bus is divided for each return group of the branch circuit having the same active phase.

3A and 3B are circuit diagrams of a branch circuit according to the present invention, in which FIG. 3A is a terminal circuit of a circuit breaker in a distribution board and constitutes a branch circuit of both 100/200 V, and FIG. 20 in the box
FIG. 3 (c) shows a case where a 4-core cable is connected to the junction box by adding a 0V circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Distribution transformer 2 Grounding (B class grounding) 3 Service line 4 Distribution board 5 Service switch, main circuit breaker 6 Active phase bus R: R phase, S: S phase 7 Neutral phase bus N: Neutral phase 8 Wiring circuit breaker, branch circuit breaker 9 Connection conductor 10 Power supply terminal, R: R phase, S: S phase 11 Load side terminal, U: U phase, V: V phase 12 Cable (100 V circuit) 13 Hot wire 14 Ground Side return line 15 Return terminal, neutral phase terminal Nu: U-phase circuit return terminal, Nv V-phase circuit return terminal 16 Light, lighting equipment 17 outlet (2P-125V) 18 outlet (2P-250V, with grounding pole) 19) Grounding pole (D-class grounding) 20 Grounding wire 21 Insulation sleeve 22 Wire end conductor 23 Colored marker 24 Connection box 25 Cable (200V circuit) 26 Wire core 27 4-core cable 28 Wire core P1 100V circuit load P2 200V Circuit negative Load pu U-phase load Pv V-phase ΣP total load Pa phases permissible maximum load ΣPa breaker permissible maximum load

Claims (3)

[Claims] 1. A two-circuit, two-pole, two-element circuit breaker is provided for each of two active phases of a single-phase three-wire main line, and a ground-side return line of the circuit is individually connected to a neutral phase. A branch circuit system in a place where electricity is used, which is configured to connect a terminal device between an active phase and a neutral phase and between active phases of both circuits. 2. The terminal of the return wire in the direction of the wire core so that the conductor portions at the wire ends of the return wire of the out-of-phase circuit do not contact each other when the ground return wire of claim 1 is removed from the neutral phase. A terminal connection method for a neutral phase, wherein the terminal group of the return or the return line is divided and arranged for each phase of the branch circuit. 3. The line end identification method for a branch circuit from a single-phase three-wire main line, wherein a color-specific marker in which a circuit breaker number is written is attached to each line pair or each core of the branch circuit according to claim 1.