JPS61139228A - Power unit housed in control panel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a dynamic crab unit housed in a highly integrated control panel, and in particular, a current transformer for detecting a load current housed inside the unit is connected to its secondary This invention relates to a movable crab knit housed in a control panel that is protected from burnout due to side opening.

[Background of the invention]

For example, ``Hitachi Hyoron J (September 1983 issue) K describes a highly integrated control panel. There is.

That is, an operating power supply unit for supplying operating power to each unit, a monitoring operation control unit such as a monitor CRT and a switch for operating facilities, an intelligent unit with sequence control functions, etc., and a moving crab unit that accommodates loads outside the panel. etc. will be accommodated. Among these, the dynamic crab unit is composed of a circuit breaker, an electromagnetic contactor, a thermal relay, a 1!1J relay module, an interlock relay module, etc., and Figure 2 shows the circuit inside the unit. There are nine configurations. As shown in Fig. 2, the moving crab knit 1 has a main circuit bus 2.
can be connected to the main circuit bus 2 and the load 10 by the power blade 3, and to the load 10 by the load blade 9.
It is assumed that the movement of the card itself into and out of the board is carried out by K. The power supply blade 3 and the load blade 9 are provided on the rear panel side. Power from the main circuit bus 2 is applied to a load 10 such as a motor via a power blade 3, a circuit breaker 4, a wire contactor contact 5, a thermal relay 6, and a load blade 9. In this case, the electromagnetic contactor 11 is connected to the operating power supply unit via the operating power connector 14, and to the intelligent unit via the 1-control line connector 15.

In addition, 12 is a relay interlock module in which each interlocking sequence and interlock logic are modularized, and 13 is a protection based on the current detected by the current transformer 7 and the zero-phase current transformer 8. Indicates the protection module that performs the action.

In general, in highly integrated control panels, operation commands are transmitted from the intelligent unit to the relay interlock module A/ in each moving unit according to the contents programmed in advance in the intelligent unit by operation commands from the supervisory operation control unit. It is supposed to be done.

This controls the supply/stop of power to the electromagnetic contactor and therefore the load.

By the way, in a highly integrated control panel, an ammeter can be inserted and connected in series to the secondary side of the current transformer in order to measure the main circuit current of the moving crab unit outside the panel. As shown in FIG. 3, the secondary side of the current transformer 7 is drawn out to the outside of the unit via the connector 16, and an ammeter 17t is connected to the connector 16. The ammeter is required in this way because it is often necessary to measure the load current near the load when the installation location of the highly integrated control panel is far from that of the load.

However, if the secondary side of the current transformer is drawn out to the outside of the unit using a connector, maintenance problems will occur. This is because when you pull out the moving crab knit toward the front inside the panel for maintenance, if you first pull out the connector, the secondary side of the current transformer will be left open and the current transformer will burn out. It means putting it away.

For this reason, test terminals such as those shown in the catalog [Hitachi MT type test terminal (APR-06A) J] have been used so far. The movable crab knit connector t-*< and the connector portion fixed to the movable crab knit side are electrically short-circuited by an internal mechanical mechanism.

FIG. 4(a), Φ) shows the test terminal in a short-circuited state and a non-shorted state, respectively. As shown in the figure, a connector portion 32 is attached to the inside 11 of the front panel 28 of the moving crab knit using mounting brackets 26 and 27, and the terminal 18
．． 19 are both connected to the secondary side of the current transformer 70. First of all, if we explain the short-circuit condition, the fourth cause (
In this state, as shown in a), the terminal 18 is connected to the conductor 20. Spring-like conductor (part of which is fixed to the conductor 20) 21, contact terminal 22,
It is connected to the terminal 19 via the conductor 24. In this case, the terminal 18 is simultaneously connected to the terminal 19 via the conductor 20, the contact terminal 25, the spring-like conductor (part of which is fixed to the conductor 24) 23, and the conductor 24. However, if the plug 31 is inserted into the connector portion 32 from the outside as shown in FIG. 4(b) in such a short circuit state, the plug 31 connects the conductor 21 and the contact terminal
, and the connection between the conductor 23 and the contact terminal 25 are both released, while the conductors 21.23 are respectively connected to the conductors 33.34 that are integrally attached to the plug 31. be. In this case conductor 33.34
are pre-connected to the ammeter 17 via terminals 29 and 30, respectively.

Therefore, if the plug 31 is pulled out from the connector part 32, the connector part 32 becomes short-circuited and the ammeter 17 becomes unable to measure, and if the plug 31 is inserted into the connector part 32, the connector part 32 becomes non-short-circuited. Therefore, the ammeter 17 is placed in a measurable state.

When using the above test terminal, the secondary side of the current transformer will not be opened when the plug is pulled out, so
Burnout of the current transformer will be prevented. however,
The test terminal has a complex structure as shown in Figures 4 (a) and (b), and its external dimensions are large, occupying a small amount of space, so the external dimensions of the moving crab knit itself have to be increased. #-1 When the external dimensions of the moving crab knit itself are increased, the number of moving crab knits housed inside the board is kept small.

[Purpose of the invention]

An object of the present invention is to provide a control panel that can be housed in a control panel that does not increase external dimensions when an ammeter for measuring load current is connected via a connector, and also prevents burnout of a current transformer due to pulling out of the connector. It is served with crab knit.

[Summary of the invention]

For this purpose, the present invention is such that the electromagnetic contactor is deenergized at the same time as the connector to which the ammeter is connected is pulled out.

[Embodiments of the invention]

The present invention will be explained below with reference to FIG.

FIG. 1 shows the structure of an example of a movable crab knit housed in a control panel according to the present invention. As mentioned above, the excitation power for the electromagnetic contactor 11 is supplied from the operation power supply unit under the control of the intelligent unit K, but at the same time as the 16 connectors (usually small ones) are pulled out, Alternatively, the excitation power source for the electromagnetic contactor 11 may be cut off immediately before its withdrawal. If the connector 16A is pulled out, the secondary side of the current transformer 7 will be released, but
Since the electromagnetic contactor contact 5 is opened almost at the same time, burning out of the current transformer 7 is prevented. By the way, the excitation power source is connected and disconnected by a connector 16B inserted in series in the power supply path. This Q connector 16
If B is configured integrally with the connector 16A or is attached in the vicinity of the connector 16A in an interlocked state, the main circuit power will be cut off at the same time as the connector 16A is pulled out. In addition, 35 shows a short circuit electric wire.

〔Effect of the invention〕

As explained above, according to the present invention, when an ammeter is connected via a connector, the external dimensions are not increased;
Moreover, there is an effect that the current transformer housed in the unit will not be burned out even if the connector is being pulled out.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the configuration of an example of a movable crab knit housed in a control panel according to the present invention together with a load and an ammeter for measuring load current, and Figs. 2 and 3 show a conventional movable crab knit housed in a control panel. Figures 4(a) and 4(b) show the configuration of the test terminal used when connecting an ammeter for measuring load current in series to the secondary side of a current transformer. FIG. 1...Moving crab unit, 7...Current transformer, 11...Magnetic contactor, 14...(Connector for operating power supply unit), 15...(Connector for connecting intelligent unit), 16A・... Connector (for connecting an ammeter for measuring load current), 16B A connector (for controlling excitation power supply).

Claims (1)

[Claims] 1. The power supply to the load is controlled by the electromagnetic contactor, and a current transformer for detecting the load current is installed downstream of the contacts of the electromagnetic contactor, and the load current is transmitted outside the unit via the connector. In the power unit housed in the control panel that is to be used for measurement, a short-circuit connector directly or indirectly connected to the load current measurement connector is provided, and the excitation power source for the magnetic contactor is connected to the short-circuit connector. A power unit housed in a control panel that is characterized by a configuration that performs power-off control.