JPH0333041Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a water resistor for power load testing, which is used during on-site load testing of diesel generators, gas turbine generators, and the like.

As is well known, generators for private use or for emergency power in factories, buildings, etc., must be regularly load tested during on-site installation and after delivery, and maintained to prevent unexpected situations from occurring in the event of an emergency. Must be.

In this case, a water resistor is mainly used as the load for the load test. The load factor is 1/4, 1/ of the rated current.
It is often the case that the test is carried out over a wide range of steps and for a long time, from light loads to overloads, such as 2, 3/4, 4/4, and 100% or more.

Conventionally used water resistors for load tests include:
The three-pole cylindrical electrode and the third
A three-pole parallel plate electrode as shown in the figure or a four-pole parallel plate electrode as shown in Fig. 4 is prepared, and electrodes 2, 2',
2" into the water storage tank 1 to adjust the infiltration area,
A method was used to adjust the load.

The size of the water tank and electrode of a water resistor is determined by the specific resistance value of the water used, the power supply voltage, and the load current.A water tank and power supply electrode with a pre-calculated volume are prepared. Generally, the load is taken up during water supply and drainage.

Recently, diesel generators, etc. are also single unit (capacity)
As the capacity increases, the voltage and load current inevitably increase, and for this purpose water resistors for load tests also need to be
You have to prepare something very large.

On the other hand, when applying a light load with a high voltage, the load current is small, so the infiltration area of the power supply electrode is small, so the electrode plunges into the water shallowly, and contact between the electrode and the water due to oscillation of the water surface, etc. There was a risk that a large arc would occur in the area, sometimes creating an explosion sound, and there was also a drawback that a considerable error occurred in the calculated values.

Furthermore, even if the water storage tank 1 is grounded, the inner wall is covered with an insulator, so the stored water will not be grounded. Therefore, the potential of the water will be the same as the power supply potential, resulting in an electric shock during a load test. There was a danger of doing so.

From this point of view, the present invention was created with the aim of eliminating the above-mentioned drawbacks, preventing danger, and further, putting into practical use a water resistor for load tests that can be used from large capacity to light (small) capacity. It is.

In the conventional method, the water temperature naturally rises only in the upper part of the water tank, while the bottom part remains cold.

Therefore, it is sufficient to stir the water, but stirring promotes arc generation, and countermeasures must be taken, such as making the water storage tank large.

Therefore, we came up with the idea of a means to flow the load current at the bottom of the water tank.

In order to take the load at the bottom of the water tank, counter electrodes are arranged at the bottom, one is fixed as a 0 potential (or negative potential) electrode, and the other is used as a power supply electrode and can be freely moved up and down in the water depth direction. In addition, current may be caused to flow only through the opposing electrodes to prevent current from flowing between the power supply electrodes.

Fortunately, large-diameter PVC pipes have recently become readily available and relatively inexpensive.
Moreover, since it is also an electrical insulator, this vinyl chloride pipe is used as an insulating cylinder and is supported upright in a water tank, and each power supply electrode is partitioned and housed in the insulating cylinder.

Both the upper and lower parts of the insulating cylinder are open, and the upper opening is provided at a position higher than the water surface of the aquarium, thereby insulating the water inside and outside the insulating cylinder.

In this way, there is no need to cover the inner wall of the aquarium with an insulating material. This was something that could not have been imagined from the conventional preconceptions of water resistors.

By using an insulating cylinder, resistance value, current value,
It becomes easier to calculate the size of the cylinder, the size of the electrode, the temperature of water, etc., and the errors are small and the test results are also good.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 5 to 7.

5, 6, and 7 are a plan view, a cross-sectional view taken along the line A-A, and a cross-sectional view taken along the line B-B of the water resistor for load testing.

11 is a water storage tank made of iron plate, 12 is an insulating cylinder made of vinyl, and the upper part of the insulating cylinder 12 is provided with an opening at a position higher than the water level in the water tank 11 to insulate the water inside and outside of the insulating cylinder 12. There is.

The insulating cylinders 12 are supported upright within the water storage tank 11, and the spacing between them is determined in consideration of the inflow of water and other balance. The distance between the insulating cylinder 12 and the bottom of the water tank is also determined to be small within a range that does not impede the inflow of water.

Reference numeral 14 denotes power supply electrodes, and the three electrodes R, S, and T can move up and down at the same speed inside the cylinder 12 at the same time, and serve to adjust the load current.

Reference numeral 13 is a rod integrated with a power supply electrode 14 that serves as power supply and electrode support.

Reference numeral 15 denotes a fixed electrode, which is set to zero potential by being grounded to the ground. In this case, the fixed electrode is a star point.

The fixed electrode 15 is arranged under the cylinder 12 and fixed to the water tank 11 via a support 16.

16 is a support base for the fixed electrode 15.

17 is a water supply pipe.

Reference numeral 18 denotes a drainage pipe, which is made of vinyl and is attached to the insulating cylinder 12 at a higher position than when the power supply electrode 14 is at the highest position. is insulated.

By supplying water into the water storage tank 11 from the water supply pipe 17, the water flows upward from the bottom of the insulating cylinder 12 and is drained from the drainage pipe 18.

In the water resistor for power load testing described above, the load current is taken through water in an insulated cylinder with a preset diameter and length, so the flow rate of water flowing inside this cylinder is adjusted to The required load is taken by moving the power supply electrode 14 up and down while taking care not to raise the temperature too much.

The feature of the present invention is that the power supply electrode arranged inside the insulating cylinder is insulated from the water tank, and the water in the upper part of the insulating cylinder is also insulated from the water in the tank.

By grounding the water tank and the fixed electrode, the water in the water tank except for the inside of the insulated cylinder and the drainage pipe becomes the same potential as the earth.

In conventional water resistors, the water in the water tank has the same potential as the power supply voltage, posing a risk of electric shock.However, the water resistor of the present invention also prevents the risk of electric shock during load tests. It is considered.

[Brief explanation of the drawing]

1 and 2 are a front sectional view and a plan view of a conventional three-pole cylindrical electrode water resistor, FIG. 3 is a plan view of a three-pole parallel plate water resistor, and FIG.
5 is a plan view of a water resistor with a water tank according to an embodiment of the present invention; FIG. 6 is a sectional view taken along the line A-A in FIG. 5; FIG. FIG. 5 is a sectional view taken along the line B-B. 1... Water tank, 2, 2', 2''... Electrode, 3...
Water supply pipe, 4... Drainage pipe, 11... Water tank, 12... Insulating cylinder, 13... Rod, 4...
... Power supply electrode, 15 ... 0 potential (or negative potential) fixed electrode, 16 ... Support stand, 17 ... Water supply pipe,
18... Drainage pipe.

Claims (1)

[Scope of utility model registration request] It is used for load testing, and has three insulating cylinders with open tops and bottoms that are supported upright at required intervals in a water tank filled with water.
The upper open end of each insulating tube is located above the water surface of the aquarium, the lower open end is positioned at a required distance from the bottom of the aquarium, and each insulating tube has an upper opening. A power supply electrode that can be freely moved up and down in the water depth direction is provided from the side, and a fixed electrode that is opposite to and grounded is provided at the bottom of the tank, as well as a water supply means for supplying water into the tank, and a power supply electrode A power load test characterized by providing an insulated drainage pipe that is connected to each insulating cylinder at a position above the position when the is at the top and discharges water in each insulating cylinder to the outside of the water tank. Water resistor.