JPH0621162Y2 - 4-pole earth leakage circuit breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a quadrupole earth leakage circuit breaker that detects a ground fault or earth leakage of a three-phase four-wire electric circuit and shuts off the electric circuit.

[Conventional technology]

FIG. 2 is a connection diagram of a conventional four-pole earth leakage breaker. Here, the 4-pole breaker ₁ connected to the power supply terminal RSTN ₁ is configured to be tripped by a trip coil 2. A primary conductor 3 is connected to each pole of the 4-pole breaker 1, and the primary conductor 3 passes through the zero-phase current transformer 4 and is connected to the load terminal UVWN ₂ . Reference numeral 5 is an overload current detection element connected to each phase except the neutral conductor N ₁ -N ₂ of the primary conductor 3. The secondary coil of the zero-phase current transformer 4 is connected to the input end of the amplifier circuit 6, and the control power supply of the amplifier circuit 6 is supplied from the load terminal UW via the transformer 7. Further, it is connected to the trip coil 2 via a contact 8 which is closed by the output of the amplifier circuit 6 from the load terminal UW.

In this four-pole earth leakage breaker, the power supply terminal RSTN ₁ is connected to a three-phase four-wire type electric circuit (not shown), and the load terminal UVWN
₂ is connected to a load (not shown). Here, when a ground fault or a leakage occurs on the load side, a zero-phase current flows in at least one of the primary conductors 3, and a zero-phase voltage is induced in the secondary coil of the zero-phase current transformer 4. This zero-phase voltage is amplified by the amplifier circuit 6,
Since the contact 8 is closed by this output, a current flows through the trip coil 2 and the cutoff unit 1 is cut off.

[Problems to be solved by the device]

Such a conventional four-pole earth leakage breaker has a power supply side electric circuit of the same phase as the load terminal UW supplying to the amplifier circuit 6, for example, when a disconnection occurs in the electric circuit connected to the power supply terminal R, the other terminals. The amplifier circuit 6 does not operate even if a ground fault or a leakage occurs in the normal load circuit connected to the VWN ₂ , and the current does not flow in the trip coil 2 either, so this 4-pole earth leakage breaker does not operate and is dangerous. There was a drawback that the continuous state continued.

The object of the present invention is to operate normally when a ground fault or an electric leakage occurs on the load side of a sound phase even if one of the power supply side wires is disconnected and control power is not supplied to the amplifier circuit or trip coil. It is to provide a four-pole earth leakage circuit breaker that operates.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the present invention provides a four-pole breaker, two sets of zero-phase current transformers through which the primary conductors connected to the four-pole breaker respectively penetrate, and the input terminals are different from each other. Two amplifying circuits individually connected to the secondary coils of the two sets of zero-phase current transformers, and one of the amplifying circuits are combined with different ones of the amplifying circuits to operate at the output of the amplifying circuits, and at least one set of the four A trip coil for shutting off the pole shutoff portion is provided, and each control power supply end of the combination circuit of the amplifier circuit and the trip coil is connected between different load terminals.

[Action]

Loads with different control power supplies for the combination circuit of the amplification circuit and the trip coil operated by the output of this amplification circuit, each of which is connected to one secondary coil of each of the two sets of zero-phase current transformers through which the primary conductor penetrates Since power is supplied from the terminal and the trip coil can be tripped independently for each trip coil, even if any one of the three-phase four-wire system connected to the power supply is disconnected, it trips with either one of the amplifier circuits. Since the control power source is supplied to the coil, the amplifier circuit and the trip coil operate to always shut off the shutoff unit.

〔Example〕

FIG. 1 shows an embodiment of a quadrupole earth leakage circuit breaker according to the present invention. The same parts as those in FIG. 2 are designated by the same reference numerals as those in FIG. In FIG. ₁ , the 4-pole breaker ₁ connected to the power supply terminal RSTN ₁ is configured to be tripped by one or both of the two trip coils 2a and 2b. A primary conductor 3 is connected to each pole of the breaking portion 1, and each of the primary conductors 3 penetrates two sets of zero-phase current transformers 4a and 4b and is connected to a load terminal UVWN ₂ . Reference numeral 5 is an overload current element connected to each phase of the primary conductor 3. The secondary coil of the zero-phase current transformer 4a is connected to the input end of the amplifier circuit 6a, and the control power supply of this amplifier circuit 6a is fed from the load terminal UV through the transformer 7a, and further from this terminal UV the amplifier circuit 6a. Is connected to the trip coil 2a via a contact 8a which is closed by the output of. The secondary coil of the zero-phase current transformer 4b is connected to the input end of the amplifier circuit 6b.
The control power source of b is connected so as to be fed from the load terminal WN ₂ via the transformer 7b. In addition, the load terminal WN ₂
Is connected to the trip coil 2b via a contact 8b which is closed by the output of the amplifier circuit 6b. Both trip coils 2
The blocking part 1 can be tripped by each of a and 2b individually or both.

When the power supply terminal RSTN ₁ is connected to a three-phase four-wire power supply and the load terminal UVWN ₂ is connected to a load and a ground fault or a leakage occurs on the load side during operation, a zero-phase current is applied to at least one wire of the primary conductor 3. Flow, a zero-phase voltage is induced in each of the secondary coils of the zero-phase current transformers 4a and 4b, and the respective amplification circuits 6
The trip coils 2a and 2b cut off the breaking portion 1 because they are amplified by a and 6b and close both contacts 8a and 8b.

Here, when one phase of the three-phase power supply, for example, the phase connected to the R terminal is open due to a disconnection or the like, and if a ground fault or a leakage occurs in the load, the two zero-phase current transformers 4a and 4b are A zero-phase voltage is induced in each of the coils, but at this time, neither the amplifier circuit 6a nor the trip coil 2a is supplied with electric power, so that the trip coil 2a does not trip. However, since the amplifier circuit 6b and the trip coil 2b are supplied with power, the contact 8b is closed, and a current flows through the trip coil 2b to shut off the breaking unit 1.
Of course, the same is true when the phase connected to the terminal S is open. Further, when any of the phases connected to the terminal T or the terminal N ₁ is missing, the breaker 1 is cut off by the operation of the amplifier circuit 6a and the trip coil 2a. That is, this 4-pole earth leakage circuit breaker surely interrupts the interruption unit 1 when a ground fault or an earth leakage occurs on the load side of a sound phase no matter which phase of the three-phase four-wire system is open.

[Effect of device]

As described above, according to the present invention, since there are two sets of amplifier circuits and two sets of trip coils, each having a different phase as a control power source, even if any one phase is open, a healthy phase load is generated. When a ground fault or an electric leakage occurs on one side, one of the trip coils always operates and shuts off the breaking unit. Therefore, there is an effect of high reliability.

[Brief description of drawings]

FIG. 1 is a connection diagram showing an embodiment of a four-pole earth leakage circuit breaker according to the present invention, and FIG. 2 is a connection diagram showing an example of a conventional four-pole earth leakage circuit breaker. 1 ... Breaking part, 2, 2a, 2b ... Trip coil, 3
... Primary conductor, 4, 4a, 4b ... Zero-phase current transformer, 6, 6
a, 6b ... Amplifier circuit.

Claims (1)

[Scope of utility model registration request] 1. A four-pole breaker, two sets of zero-phase current transformers through which the primary conductors connected to the four-pole breaker pass, respectively, and the two sets of zero-phase transformers having different input terminals. Two amplifying circuits individually connected to the secondary coil of the current transformer and one of the two amplifying circuits, which are different from each other, are operated to operate at the output of the amplifying circuits and at least one set cuts off the four-pole cutoff unit. A quadrupole earth leakage circuit breaker, comprising: a trip coil; and a control power source end of a combination circuit of the amplifier circuit and the trip coil is connected between different load terminals.