What should be paid attention to in the use and maintenance of DC high voltage generator straight h

What should be paid attention to in the use and maintenance of DC high-voltage generator (straight high hair).

1. Precautions for DC high-voltage generator test.

1.Before the test, check whether the test product, DC high voltage generator, voltage doubler, discharge rod, grounding wire, and test product connection wire are connected correctly, and check whether the grounding wire is connected correctly.

2.The high-voltage output wiring must be firm to prevent the high-voltage lead from falling off during the test and damaging the instrument by direct discharge to the ground.

3.During high-pressure tests, it is important to keep a safe distance between surrounding objects and people.

3.Before the working power supply enters the tester, install two distinct disconnect points. When replacing the product under test and wiring, the disconnection point of the working power supply should be significantly disconnected;

4.In the process of cable withstand voltage test, the step-up process should be uniform and slow, and the step-down process should also be uniform and slow. At the same time, a protective water resistor should be added at the high-voltage output end. Otherwise, the reverse voltage can easily damage the instrument.

5.For the discharge of large capacitance specimens, a 100 V discharge resistance rod should be used to discharge the specimen. When discharging, the discharge rod should not immediately touch the specimen.

The discharge rod should gradually move closer to the specimen and the free discharge will begin to hiss at a certain distance from the air gap. When there is no sound, it can be discharged with the ground end of the discharge rod and then directly connected to the ground wire.

6.When the DC voltage of the DC high-voltage generator is 200kV and above, although the tester wears insulated shoes and is located in an area outside the safe distance, several adjacent stations will produce different DC potentials due to the influence of the spatial electric field distribution of high-voltage DC ions. Testers should not shake hands with each other or touch the grounding point with their hands, otherwise there will be a slight electric shock, which is more obvious in dry areas and winter, but due to the low energy, it will generally not cause harm to people.

7.After the end of the test, the test product should be discharged multiple times with a discharge rod, and the test product can be completely discharged before it can be approached for subsequent disassembly.

8.The interval between the two tests (referring to the power-off time) should not be less than 5 minutes to ensure that the instrument can be fully dissipated.

2. Precautions for the maintenance of DC high-voltage generators:

1.Prevent foreign objects from entering the control box. If there is a fan in the control box, check frequently that the fan is working properly.

2. Frequently check the dust-proof devices everywhere, and if they are found to be damaged or loosely connected, they should be dealt with in time to prevent dust from mixing in and damaging the equipment.

3.When the insulation cylinder of the pressure doubling cylinder becomes dirty, wipe it with a dry cloth. Do not scrub with organic solvents such as alcohol and gasoline, but wash with dish soap.

4.When replacing the fuse, replace the fuse according to the amperage calibrated next to the fuse base.

5.Do not open the control box and pressure doubling cylinder without permission, otherwise it will affect the product warranty.

6.The instrument should be shockproof, moisture-proof, dust-proof, and corrosion-proof.

7.Check the voltage and ammeter regularly to ensure the accuracy of the instrument.

DC high-voltage generator, also known as high-voltage generator, is mainly suitable for power maintenance departments, industrial and mining, metallurgy, steel and other enterprise power departments to carry out DC withstand voltage tests on high-voltage electrical equipment such as zinc oxide arresters, power cables, transformers, generators, and high-voltage switches.

The characteristics of DC high-voltage generator are mainly large output power, small size, light weight, reliable over-voltage, over-current and zero closing protection functions, increase the AC voltage input of the transformer hundreds of times, and then rectify to provide the DC high voltage required for X-ray tube generation. The AC voltage input to the primary circuit of the X-ray tube filament is also reduced to provide a heating voltage for the X-ray tube. If there are more than two X-ray tubes, the switch between the tube voltage and the filament heating voltage should be completed.

DC high voltage generators.

The following are common troubleshooting tips for DC high voltage generators:

1. When the power switch is turned on, the digital display on the control box does not light up.

Please check the power supply cable and all fuses, if the fuses are damaged, please replace them with new ones according to the amperage marked next to the fuse header.

2. If the power switch is turned on, the digital display is on, and the high-voltage display light (green) is not on, and the high voltage cannot be added.

Fault display"Back to zero"The lights are on.

If there is no return to zero, turn the high-voltage output adjustment knob and fine adjustment knob counterclockwise back to the zero position"Back to zero"When the light is off, the high pressure can be increased.

Fault display"Miscellaneous"There are two phenomena when the light is on, 1. Grounding protection and 2. Disconnection protection.

a.It is possible that the ground wire is not properly connected, or the ground wire is not reliably grounded. Please connect the reliable ground cable, turn off the power, and restart.

b.It may be that the cable connecting the control box and the high-voltage tower is not connected, please turn off the power and restart the cable. Or this fault will occur when the welding heads at both ends of the cable are desoldered, please solder the welding heads at both ends of the cable, turn off the power, and restart.

c.It is possible that a certain wire head in the control box is desoldered and disconnected, please re-solder, turn off the power, and restart.

3. Everything is normal, but it is protected in the process of not rising to the rated output voltage.

Fault display"Overcurrent"The lights are on.

a.The specimen is short-circuited, or the leakage current is too large.

b.When a load is large, the boost is too fast. Turn off the power and restart, slow down the boost.

Fault display"Overvoltage"The lights are on.

If the overvoltage protection setting knob is not placed in the large place, please rotate it clockwise to the large place, turn off the power and restart.

4. When a short circuit occurs under the high voltage of the sample, due to the large short-circuit current, it is possible to light up all the fault display lights, which is normal, please restart after eliminating the fault of the sample.

5. After the sample is troubleshooting, the fault display light is still on, and the high voltage cannot be added.

The power switch doubles as a failsafe reset switch, please turn off the power switch, restart, and the voltage can be boosted.

6. If you find that the number of the voltmeter fluctuates greatly, please check whether the 7-pin shielding net head and the central shielding wire end of the aviation plug at both ends of the connecting cable are unsoldered and disconnected, if so, please solder.

A DC high voltage generator is an instrument that provides a high voltage DC source, and the instrument must be reliably grounded before using the instrument. The staff who use the DC high-voltage generator must have a "high-voltage test certificate". When using a DC high-voltage generator, the user must follow the provisions of Article 168 of the "Electric Safety Regulations" and install two obvious disconnection points before the working power supply enters the tester.

When replacing the test product and wiring, the two power disconnection points should be significantly disconnected first. At the same time, at least three staff members must be on site, so as to effectively ensure the safety of users. Before turning on the power supply on the instrument, make sure that the DC high-voltage generator is connected to the 220V AC power supply, carefully check whether the wiring is correct, and also check whether the wiring of the high-voltage discharge pole is reliable.

In the process of step-up and downing of DC high-voltage generator, it is necessary to maintain slow rise and fall, and stable step-up is one of the most important points to extend the service life of DC-voltage generator. Also, try to avoid over-measuring the use of the instrument. At the end of each test, the potentiometer is returned to the zero position, and then the power supply is cut off to discharge the tested product, and the discharge process is divided into two steps.

When discharging, the discharge rod can not immediately contact the sample, the discharge rod should be gradually approached to the sample, to a certain distance from the air gap to start free discharge, there is a hissing sound, when there is no sound, the discharge rod can be used to discharge, and finally directly connected to the ground wire discharge. When the DC high voltage is 200kV and above, although the tester wears insulated shoes and is in an area outside the safety distance, due to the influence of the spatial electric field distribution of the HVDC ions, several people standing next to each other will have different DC potentials. Testers should not shake hands with each other or touch the grounding body with their hands, otherwise there will be a slight electric shock, which is more obvious in dry areas and winter, but due to the small energy, it will generally not cause harm to the human body.

The power supply of the DC high voltage generator control box is AC AC220V 10%, 50Hz. If the power supply is isolated by 1 1 or the self-generated power supply is used in the field, the power supply must be artificially connected to the ground at one point.

Maintenance of DC high voltage generators.

1. Replace the hydraulic oil and clean the oil tank once every six months, and the oil must be of the recommended model;

2. When the gas is hot, often check whether the cooling device is automatically started (when the oil temperature is 45 degrees). (The cooling water temperature must be lower than 30 degrees).

3. Clean the air filter while cleaning the fuel tank;

4. Always check the oil filter signal light of the DC high-voltage generator, and clean the oil filter immediately as soon as the signal light is on (and the buzzer will sound at the same time);

5. Inject oil into each lubrication point of the mechanical transmission part of the equipment according to the regulations;

6. Observe the liquid condition frequently, and when the liquid level is close to the lower limit, please replenish the recommended hydraulic oil to the oil tank in time;

7. Frequently check the dust-proof devices everywhere, and if they are found to be damaged or loosely connected, they should be dealt with in time to prevent sand and dust from mixing in and damaging the equipment.

Resources.

DC high voltage generators.

The product is composed of two parts, the operating table and the current booster, which has the characteristics of stepless adjustment of output current, stable current rise, large load change range, reliable work, simple and safe operation, etc., and can also be used as a current source equipment for industrial and mining enterprises to carry out current rise or temperature rise test. Equipped with a transformer, the test current value can be easily read.

Use and Maintenance:

1. Check whether the main circuit terminal is loose and whether the voltage regulator brushes are in good contact.

2. When not in use for a long time, the insulation resistance of the main circuit to the ground should be checked by a 500V megohmmeter before use, and its resistance should not be less than a meghom.

3. The input voltage conforms to the voltage value on the nameplate, and the value difference should be 10%, and the frequency is 50Hz.

4. The current gear switch is not allowed to operate with load.

5. When operating, the handwheel should be rotated evenly and slowly to avoid damage to the pressure regulator.

6. The working time shall not exceed 5 minutes at full load, and the continuous working time shall be less than minutes, but the working cycle shall be greater than 10 minutes.

7. The casing of the riser has a grounding terminal, which should be well grounded when used.

Precautions: 1. The staff who use the high-frequency DC high-voltage generator must have a "high-voltage test certificate".

2. The use of this instrument must be in accordance with the provisions of Article 168 of the "Electric Power Safety Regulations".

3. Before the test, please check whether the grounding wires of all test wiring, control box, doubler cylinder and test product are connected. The grounding wire of the test loop should be grounded at one point according to the requirements of this instrument manual.

4. For the discharge of large capacitance samples, special discharge resistance rods are used to discharge the samples.

5. When the DC high voltage is 200kV and above, although the tester wears insulated shoes and is in an area above a safe distance, due to the influence of the spatial electric field distribution and expansion of the high-voltage DC ion space, several people standing next to each other will have different DC potentials. Testers should not shake hands with each other or touch the grounding body with their hands, otherwise there will be a slight phenomenon, which is more obvious in dry areas and winter, but due to the small energy, it will generally not cause harm to the human body.

6. The power supply of the control box of the high-frequency DC high-voltage generator is AC 220V 10%, 50Hz. If the power supply is isolated by 1 1 or the self-generated power supply is used in the field, the power supply must be artificially connected to the ground at one point.

1) Output voltage.

There is a margin for the highest test voltage among the various products under test.

2) Output current.

According to the maximum test crack flow of various tested products, a margin of more than 30% should be considered, generally 2-10mA.

3) Ripple factor.

When testing the leakage current, conduction current and 1mA DC voltage of various arresters, a DC high-voltage generator with a ripple coefficient of less than or equal to that should be selected should be selected. When conducting DC leakage current and DC withstand voltage tests for general high-voltage electrical equipment, DC high-voltage generators with ripple coefficient not greater than are allowed; All things considered, it is advisable to choose a DC high-voltage generator with a ripple coefficient less than or equal to.

4) Output voltage measurement error.

If the test duration does not exceed 60s, the measurement error of the test voltage should be kept within 1%, and if the test duration exceeds 60s, the measurement error of the test voltage can be kept within 3%. In general, the measurement error of DC voltage should be within 1%.

5) Output voltage polarity.

In the field DC voltage test, in order to prevent the external insulation flashover and easy to find defects such as insulation moisture, negative DC voltage is usually used.

6) Measurement function and accuracy.

The DC generator should have the function of measuring the output voltage, and the measurement error of the voltage divider should not be exceeded. Install a digital micro-ampere meter that directly measures the leakage current on the high-voltage side in the equalizing hood of the DC generator, or connect an external micro-ampere meter on the high-voltage side, and the measurement error of the micro-ampere meter should not exceed; The high-voltage generator has the function of measuring the leakage current of the gapless metal oxide arrester at times the U1mA voltage, which is very convenient.

7) Height. When the output voltage, current, ripple coefficient, measurement accuracy and other technical indicators of the DC generator are the same, the light weight and small size are better. However, also pay attention to the size.

The height of the insulating barrel of the 200kv DC high voltage generator produced by some manufacturers is small, which is acceptable in laboratory conditions or dry environment. However, in the field, especially when the relative humidity of the air is high, the creepage on the surface of the insulating cylinder is serious, which will directly affect the technical performance of the DC high-voltage generator, and even cause flashover along the surface. For DC high-voltage generators with a rated voltage of 200kv, the effective height of the insulating cylinder should not be less than.