SU370592A1 - METHOD OF CREATING AN EQUIVALENT LOAD FOR TESTING LOW-VOLTAGE COMMUTATION - Google Patents

Description

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The invention relates to the field of testing low voltage adhesion devices, for example, a FSCTOpoB or a relay manufactured by the electrical or aeronautical industry.

There is a known method of creating an equivalent load load for testing contactors or relays in which the rated current through the contactTb of the test contactor or relay is provided by switching on the nominal voltage of the ballast load in series with the contacts in the circuit of one powerful power source.

The starting current when the contacts are closed is simulated by shunting a part of the load by a signal from the test control circuit of the contactors or the relay. However, when implementing this method, a large amount of electricity is wasted aimlessly on the ballast load.

The change of the ballast load is not synchronized with the switching of the contacts of the tested contactor or the relay, since the switch control of the load is produced by a signal from the test control circuit, which leads to additional power consumption.

The purpose of the invention is to simplify and increase the effectiveness of the tests,

It achieves this, that the rated current through the contacts is being tested by a contactor or

relays and nominal voltages provide two power supplies, but much lower power. One of the power sources, low-voltage, has a minimum voltage and provides the rated current through the contacts, and the other, pulsed, is the nominal voltage at the minimum current. During switching, imitation of starting current and breaking capacity are provided by a single power source, for which the low-voltage power source of the rated current is disconnected, and the current through the contacts of the test contactor or relay is increased from the switching power source of the nominal voltage to a predetermined switching current.

The change in the load mode before closing and opening the contacts is controlled by the signal received from the electromagnet coil of the tested coytractor or relay when it is turned on and off, thereby synchronizing the change in load current before switching the contacts.

When implementing the proposed method of creating an equivalent load, it is possible to test contactors or relays with low power consumption, since a power source having a minimum voltage and, consequently, low power consumption, is used to create the ground current. In order to provide a rated voltage, a second power supply is used, having a minimum current, but this source also has low power consumption.

The control of the change in load current before shorting and opening the contacts of the test contactor or relay is carried out by a signal from the electromagnet coil of the same contactor or relay, which provides automatic selection of the current mode during switching, thereby resulting in additional energy savings.

The drawing shows a block diagram of an apparatus for carrying out the proposed method.

The circuit consists of a test switching device /, a test control unit 2, a load control unit 3, a ballast load device 4, a switching device 5, a pulsed power source 6 of nominal voltage and minimum current, a low-voltage power source 7 of minimum voltage and rated current, load devices 8.

The contactors or relays are tested as follows.

Power supplies 5 and 7 are included. When a signal is received from the test control unit 2 to turn on the test switching device I, the signal goes to the load control unit 3. From the load control unit, the signal goes to the switching device 5 and the ballast load device 4. During the current rise time in the electromagnetic coil, the source the power supply 7 is turned off and at the same time bypassing part of the resistance of the ballast loading device 4. Upon reaching the electromagnet of the switch under test in the coil Ion apparatus / actuation current; its contacts close the circuit of the power supply source 6 with a series-connected, partially shunted resistance of the ballast loading device 4, providing the specified starting current.

In this way, the contactor or relay is turned on at starting current and rated voltage. In this case, or / n / 6 with Un f / &.

After the contacts of the tested switching device are closed / the load control unit 5 removes the signal from the switching device 5 and from the ballast loading device 4, the power supply 7 is turned on and the shunted part of the resistance of the ballast loading device 4 is simultaneously discharged. power supply / through load device 8 is provided with a rated current with minimum voltage, and

from the source of electronic power 6 through the ballast load device 4 - the nominal voltage with a minimum current.

In this case / „/ b + / 7, with / / e and 5,

where / n - rated load current; fe, is the current and voltage of the power supply 6;

h, 7 - current and voltage of the power supply source 7.

Thus, when the contacts are turned on, the circuit provides the starting current through the contacts at rated voltage and from the power source 6 when the M power supply 5 is disconnected. In the switched on state of the contacts, the circuit provides the rated load current at the minimum voltage from the power supply 7 and rated voltage at minimum current from a power source 6.

When a signal is received from the control unit of test 2 for switching off the switching device / a signal is given to the control unit of loads 3. From the control unit of loads, signals are sent to the switching device 5 and the ballast loading device 4. During the current decline in the coil of the electromagnet of the test switching device 1 The contacts of the contacts turn off the power supply 7 and change the response of the ballast loading device 4 to ensure a predetermined breaking capacity.

In this case, n; (, 5 where / n - rated load current,

Ui, is the rated voltage, / 6, 6 is the current and source voltage

power supply 6.

After a complete break of the load circuit 0 by contacts, the load control unit 3 removes the signals from the switching device 5 and from the ballast loading device 4. The circuit is restored, i.e. the power supply 6 again has a minimum 5 current and rated voltage, and the power supply 7 is rated current and minimum voltage.

Consequently, when implementing the proposed method, the test mode of the contactors or relays is retained, but with the cost of electricity 10-15 times less than with the existing test method.

Subject invention

55 A method of creating an equivalent load for testing low-voltage switching devices, such as contactors or relays, for durability and heat resistance of contacts with a simulated starting current at

0 given current, voltage and breaking capacity, distinguished by the fact that, in order to simplify and increase the test efficiency, the switching and heating mode of the contacts is provided with two power sources, one of which, low-voltage, is provided with closed current, and the second , pulsed, is the nominal voltage at the minimum allowable current, and during the switching period of the contacts, the pulsed source provides the specified starting current and breaking current

the power is turned off when the low-voltage power supply is disconnected, and the switching of the power sources and, thus, changing the load conditions of the contacts is controlled by storing the electromagnet from the apparatus under test.