JPH02155134A - Throw-in command circuit for breaker - Google Patents

Abstract

PURPOSE:To avoid burning of a breaker throw-in coil by breaking a throw-in command current flowing through the coil of the second auxiliary relay having the current breaker capacity larger than that of the first auxiliary relay with the use of an auxiliary contact which is opened or closed according to operation of the breaker. CONSTITUTION:There are provided the first auxiliary relay 2 of high speed operation type which is energized by switching of a throw-in command contact 1, and the second auxiliary relay 3 of current energizing type having the current breaker capacity larger than that of the first auxiliary relay 2 which is energized by closing the output contact 2a of the first auxiliary realy 2. Further, there are provided the auxiliary contact 4a of the breaker which is connected to the second auxiliary relay 3 in series and closed according to operation of the breaker, and a breaker throw-in coil 4 which is connected to the auxiliary contact 4a of the breaker in series. The output contact 3a of the second auxiliary relay 3 is connected in parallel to the output contact 2a of the first auxiliary relay 2. Thus, the high speed closing is ensured and the output contact 2a is protected, while it is prevented that current is applied in the second auxiliary relay 3 for a long time, to thereby avoid burning of the breaker throw-in coil.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high-speed operation, large-capacity auxiliary relay circuit used when commanding a circuit breaker to close.

BACKGROUND ART] FIG. 2 shows a conventional immersion command circuit for a breaker shown in, for example, Utility Model Publication No. 1983-H94.

In Figure 2, the closing command contact (
When 1) opens, the first auxiliary relay (2) of high-speed operation type
operates at high speed, its first output contact (2a) opens, and the first immersion signal current flows through the closing coil (4) of the breaker. At the same time, the second output contact (2b) is closed and the second auxiliary relay (3) with a large current breaker capacity is activated, and then its output contact (3a) is opened and the first auxiliary relay (3) is activated.
2) output contact (2a) is bypassed and protected. When the closing command contact (1) returns, first the first auxiliary relay (2)
is restored, thus the first and second output contacts (2a) (2b) of the first auxiliary relay (2) are opened, and subsequently the second auxiliary relay (3) returns to 1N. If you do this, the current bus (5P) will be cut off from the R31M coil (
The control current flowing through 4) to the power bus (5N) is cut off by opening the output contact (3a) of the second auxiliary relay (3). As a result, the first output contact (2a) of the first auxiliary relay (2) is protected, and a high-speed operation large-capacity contact auxiliary relay circuit can be obtained.

[Problems to be Solved by the Invention] Since the closing command circuit of a conventional circuit breaker is configured as described above, if the closing command contact (1) operates and immediately returns to normal, the amount of current cutoff will be reduced. Since the output contact (3a) of the high-voltage type second auxiliary relay (3) has not reached an open circuit, the first output contact (2a) of the high-speed operation type first auxiliary relay (2) circuits and is cut off. This will cut off the current flowing to the closing coil (4) of the device, and there is a possibility that its first output contact (2a) will burn out. In order to shorten the time during which this possible burnout occurs, it is conceivable to use a current-energized type auxiliary relay that operates at a higher speed in place of the voltage-type second auxiliary relay.

When using this current-energized auxiliary relay as a second auxiliary relay, the coil of the current-energized auxiliary relay may burn out if the closing signal current continues to flow to this relay for a long time. It was possible. Therefore, as described in the [Prior Art] section, while protecting the output contact (2a) of the first auxiliary relay (2), the possibility of burning out of the coil (4) as described above is avoided. It is necessary to do so. This is the problem of the present invention.

[Means for Solving the Problems] A closing command circuit for a circuit breaker according to the present invention includes a first auxiliary relay (2) of a high-speed operation type that is energized by opening of a closing command contact (1), and the first auxiliary relay (2). A current-energized second auxiliary relay (3) having a larger current breaker capacity than the first auxiliary relay, which is energized by closing the output contact (2a) of the auxiliary relay (2).
and an auxiliary contact (4a) of the breaker connected in series to the second auxiliary relay (3) and opened in response to the operation of the breaker; and a breaker connected in series to the auxiliary contact (4a) of the breaker. the output contact (3a) of the second auxiliary relay (3) is connected in parallel to the output contact (2a) of the first auxiliary relay (2). .

[Function] According to the present invention, when the closing command contact (1) operates and returns immediately, a current with a large amount of current interruption is applied to the output contact (2a) of the high-speed operation type first auxiliary relay. The output contacts (3a) of the second auxiliary relay in the configuration are connected in parallel to bypass at high speed and protect the output contacts (2a). Further, since the auxiliary contact of the breaker, which opens in response to the operation of the breaker, is connected in series to the second auxiliary relay, current does not flow continuously for a long time to the second auxiliary relay.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
In the figure, a high-speed operation type first auxiliary relay (2) is connected in series to the closing command contact (1) of the breaker. Next, a circuit in which the output contact (2a) of the first auxiliary relay and the output contact (3a) of the second auxiliary relay, which is a current-energized type that has a larger current interruption amount than the first auxiliary relay, are connected in parallel. A second auxiliary relay (3), an auxiliary contact (4a) of the breaker that opens in response to the operation of the breaker, and a breaker closing coil (4) are each connected in series.

In Figure 1, when the closing command contact (1) opens to close the breaker, the first auxiliary relay (2) of the high-speed operation type
) operates at high speed, its output contact (2a) closes, and the closing signal current for the breaker closing coil (4) flows from the power bus (5P) to the power bus (5N).

Next, due to the operation of the second auxiliary relay (3), which is a current-energized type with a large amount of current interruption, its output contact (3a) is opened, and the output contact (2a) of the first auxiliary relay (2) is opened. Detour and protect. Then, in response to the operation of the circuit breaker, a second
The auxiliary contact (4a) of the breaker inserted between the auxiliary relay (3) and the breaker closing coil (4) opens, and the closing signal current is cut off. As a result, regardless of whether the closing command contact (1) is closed or not, the closing signal current will not flow to the current-energized second auxiliary relay (3), thereby avoiding coil burnout. .

Normally, the auxiliary contact (4a) of this breaker is inserted at this position, but there are also other positions where the immersion signal current is not bypassed, such as between the breaker closing coil (4) and the power bus (5N), etc. The same effect can be achieved even if inserted in

Although the circuit breaker closing command circuit has been described in the above embodiment, a circuit breaker tripping circuit may also be used, and the same effects as in the above embodiment can be achieved.

[Effects of the Invention] As described above, according to the present invention, the immersion command current flowing through the coil of the second auxiliary relay is interrupted by the auxiliary contact that opens in response to the operation of the breaker, thereby avoiding burnout of the coil. This makes it possible to use a fast-acting current-energized auxiliary relay as the second auxiliary relay. This has the effect of shortening the time during which the contacts of the first auxiliary relay may burn out.

[Brief explanation of the drawing]

FIG. 1 shows a circuit breaker closing command circuit according to an embodiment of the present invention, and FIG. 2 shows a conventional circuit breaker closing command circuit. In the figure, (1) is the closing command contact, (2) is the high-speed operation type first auxiliary relay, (3) is the current energized type second auxiliary relay with large current breaking capacity, and (4) is the breaking The operator coil (4a) is the auxiliary contact of the breaker.

Claims (1)

[Claims] (1) A high-speed operation type first auxiliary relay that is energized by the closing of the closing command contact, and a current that is higher than the first auxiliary relay that is energized by the closing of the output contact of the first auxiliary relay. a current-energized second auxiliary relay with a large breaker capacity; an auxiliary contact of the breaker that is connected in series with the second auxiliary relay and opens in response to the operation of the breaker; A breaker closing command circuit comprising: a breaker closing coil connected in series to a contact; and an output contact of the second auxiliary relay connected in parallel to an output contact of the first auxiliary relay.