JPS58168978A - Testing device for tracking - Google Patents

Abstract

PURPOSE:To obtain a sufficient tracking resistance characteristic even in an actual equipment shape, by applying a prescribed voltage across both end electrodes to be tested in a tank for an electrolyte, and varying the level of an electrode liquid. CONSTITUTION:A body 3 corresponding to an actual equipment is suspended fixedly in the tank 6 by a suspending device 1 so that electrodes 4a and 4b are at a higher and a lower position respectively. In this state, a prescribed voltage is applied between the electrodes 4a and 4b by a electric feeding device 20 and the electrolyte 5 is supplied into the tank 6 by a pump 7. This supply is continued until the liquid level 10 of the liquid 5 contacts the electrode 4a by an upper limit switch 8. Then, the liquid 5 is discharged out of the tank by the pump 7 and when the level 10 reaches the electrode 4b, the pump 7 is stopped through a lower-limit switch 9. This state is held until discharging is not generated on the surface of the body 3 any more. This operation is repeated until an electricity conduction path is formed in the body 3 and a current regarded as the destructive current flows. The tracking resistance characteristic of the body 3 is evaluated from the frequency of the repetition.

Description

[Detailed Description of the Invention] Description of the Technical Field The present invention relates to a tracking test device that can evaluate even a product equivalent to an actual device by fixing the object under test. A tracking test device is used as a device to determine the degree of damage. Typical tracking test methods include the method established by the International Electrical Association, and similar methods include the inclined plane test method and the like. However, their biggest drawback is that the test object is limited to a relatively small flat specimen.

As described above, since the shape and dimensions of the test object are limited, it is impossible to conduct a tracking test using the actual machine, and the tracking resistance is evaluated using a test piece made of the same material as the actual machine. In this way, when evaluating tracking resistance using a test piece, the shape effect in the actual machine is completely ignored, and the test becomes a mere material screening test. Generally, materials with excellent tracking resistance are expensive, and the challenge is how to provide electrical equipment with excellent tracking resistance at a low cost. However, in the above-mentioned tracking test method, etc., the shape of the test object is limited, so it is not possible to evaluate the tracking resistance including the shape effect of the material. Therefore, if the tracking resistance of a material is evaluated using the above-mentioned tracking test method, expensive materials will ultimately be used. Generally, when an organic insulator is actually used, its shape greatly influences the insulation life due to tracking deterioration. Therefore, by changing the shape, it may be possible to significantly improve the lifespan even with inexpensive materials.

OBJECTS OF THE INVENTION An object of the present invention is to provide a tracking test device that can sufficiently evaluate tracking resistance even in the shape of an actual machine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below with reference to an embodiment shown in the drawings. In Fig. 1, 31 is a test object in the shape of an actual machine;
At both ends there are electrodes 4a equivalent to the actual machine.

4b is provided. 6 is a liquid tank for electrolyte solution, and the above-mentioned test object 3
It is large enough to accommodate the whole thing.

Reference numeral 1 denotes a suspension device, which has a support member 11 and an insulator 12 made of porcelain or the like, and suspends the test object 3 at a predetermined position in the liquid tank 6 so that the electrodes 4a and 4b are positioned above and below. .

Reference numeral 7 denotes an electrolyte supply/drainage device, which uses, for example, a pump. The electrolytic solution 5 is supplied to and discharged from the pump 7 into the liquid tank 6 at preset intervals. 8 is an upper limit switch, and 9 is a lower limit switch, which are used when the liquid level of the electrolytic solution 5 in the liquid tank 6 reaches a level opposite to the upper electrode 4a of the test object 3 and a level opposite to the lower electrode 4b. t'l is detected, and the operation of supplying or discharging the electrolyte 5 by the pump 7 is controlled to stop.

The upper and lower limit switches 8.9 may be of any type as long as they can detect the liquid level, and may be float switch-shaped, electrode rod-shaped, or the like.

Reference numeral 20 denotes a power supply device, which has a power transformer 22 that applies a predetermined high voltage in full between electrodes 4a and 4b of the object under test 3 via a high voltage limiting resistor 21. 23 is an overcurrent relay,
It operates by detecting an overcurrent flowing between the electrodes 4a and 4b due to the generation of a conductive path or the like. 24 is a timer which, when the operation of the overcurrent relay continues for a set time, determines that a conductive path has occurred (insulation breakdown) and opens the power supply circuit.

Effect of the Invention First, the test object 3 equivalent to an actual machine is attached to the electrode 4a by the suspension device 1.
and 4b are positioned above and below, and the suspension support is fixed so as to fit completely into the liquid tank 6. In this state, a predetermined voltage is applied by the electrostatic device 20 between the electrodes 4a and 4b at the upper and lower ends of the test object 3, and the electrolytic solution 5 is supplied to the liquid tank 6 by the pump 7. This supply is continued until the upper limit switch 8 causes the creeping surface 10 of the electrolytic solution 5 to come into contact with the electrode 4&. In this case, in order to ensure that a large current flows through the electrolytic solution 5 to the electrodes 4m and 4b, the time during which the electrode 4a of the test object 3 is in contact with the electrolytic solution 5 is preferably 1 to 2 seconds. Of course, the timer 24 provided in the power charging device 20 is set not to operate during this time. Thereafter, the electrolytic solution 5 is discharged from the liquid tank 6 by the pump 7. , this discharge causes the liquid level 10 of the electrolytic solution 5 to rise to the electrode 4
When it reaches the same position as b, the lower limit switch 9 stops the pump 7 and the discharge of the electrolyte 5 is stopped. Although the time to remain in this state varies depending on the conductivity of the electrolytic solution 5, the voltage, and the distance between the electrodes 4& and 4b, it is desirable to maintain this state until no discharge occurs on the surface of the test object 3. This change in liquid level is as shown in FIG. This operation is repeated until a conductive path is formed in the test object 3 and a current that is considered to be destructive flows. The tracking resistance of the test object 3 is evaluated based on the number of repetitions. It should be noted that the overcurrent relay 23 and the timer 24 can detect whether or not a current that is considered to be destructive has flowed, so that all control of the device is performed automatically.

In this case, once the test object 3 is fixed, there is no need to move it until the end of the test. Furthermore, since the upper limit switch 8 is provided, there is no drawback that even if the electrolytic solution 5 evaporates, the test object 3 is not completely immersed in the electrolytic solution 5, and an accurate test can be performed. Moreover, the repetition pattern of supplying and discharging the electrolyte 5 to the test object 3 can be easily adjusted by automatically changing the rotation speed of the pump. It can be of any shape and can be used for screening standard test pieces such as flat plates and round bars.

As described in detail, according to the present invention, a predetermined voltage is applied to the electrodes at both ends of the test object 30 in the electrolytic solution tank, and the liquid level of the electrode solution is changed. If the test object is fixed at 1F before the test, there is no need to move the test object until the end of the test. Therefore, even if the specimen to be tested is as large as the actual machine and has a complex shape, it can be tested as is, and the tracking resistance characteristics corresponding to the actual size and shape can be tested without testing with a test piece as in the past. Obtainable.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a tracking test device according to the present invention, and FIG. 2 is a diagram showing time on the horizontal axis and electrolyte solution when the vertical axis of the test object is taken on the vertical axis. It is a figure which shows the pattern of a surface. . 1... Hanging support device 3... Test object 4m, 4b
... Electrode 5 ... Electrolyte 6 ... Liquid tank
7... Electrolyte supply/drainage device 8... Upper limit switch 9... Lower limit switch

Claims (1)

[Claims] a liquid tank that can house the entire test object and has electrodes at both ends;
A suspension device that suspends the above-mentioned test object at a predetermined position in the liquid tank so that the electrodes at both ends are positioned above and below, and an electrolyte supply/drainage device that supplies and drains the electrolyte to and from the liquid tank at predetermined intervals. an upper limit IJj that detects when the electrolyte rises to a level facing the upper electrode of the device and the test object suspended in the liquid tank and stops the supply operation by the electrolyte supply and discharge device;
and a lower limit switch that detects when the electrolyte reaches a level facing the electrode at the bottom of a test object suspended in the liquid tank and stops the electrolyte supply/discharge device from discharging. and a voltage applying device that applies a predetermined voltage to both ends of a test object suspended in the liquid tank.