Features
suitable for use as insulation test in maintenance, repair, verification and test a variety of electrical devices. Insulation resistance reticle clear and homogeneous, to facilitate accurate reading. Simple operation, easy to carry. Low power consumption, with 8 × 1.5V (AA, R6) battery, use a long time. Having a battery capacity check function. There are single-voltage and dual voltage models models, rated voltage ranges reasonable configured in a variety of specifications, widely applicable. The use of advanced digital processing technology, capacity, anti-interference ability, can meet the requirements for high pressure, high resistance, high capacity load test, illustrating the value of accurate, stable and reliable. Shock, moisture, dust-proof structure, adapted to the harsh working environment. Protection function, the short-circuit withstand impact and residual voltage measured capacitance.
test voltage: 0V ~ 10000V Specifications are therebetween, and may require customized
500V ~ 2500V
2500V ~ 5000V
test range: 0 ~ 19999MΩ, 0 ~ 200000MΩ
power: DC9 ~ 12V
weight: 1kg
product structure
1, high voltage insulation resistance tester is mainly composed of three parts.
is a first DC high voltage generator for generating a DC high voltage.
is a second measuring circuit.
is a third.
(1) DC high voltage generator
measure the insulation resistance must be applied to a high voltage at the measuring terminal, the high voltage value is defined as 50V, 100V, 250V insulation resistance meter national standard, 500V , 1000V, 2500V, 5000V ...
generatingDC high voltage are generally three methods. A first hand as a generator. my country's production of ZhaoOuBiao about 80% using this method (shake table origin of the name). The second is through mains step-up transformer, rectified DC high voltage. The method generally mains megger used. A third benefit is the DC high voltage transistor to generate an oscillating pulse width modulation circuit or dedicated, cell type, and general formula mains insulation resistance meter using the method.
(2) measuring circuit
in the front speakers shake table measuring circuit and a display portion engaged (megger) are two for one. It is a complete flow ratio of up table, the two header angle of 60 ° (left and right) of the coils, and wherein a coil is a voltage across the other coil in the measuring circuit is a string middle. Table pointer deflection angle depends on the ratio of currents in the two coils of different deflection angles represent different resistance, measuring the resistance, the greater the smaller string measuring the coil current circuit, the larger the angle of deflection of the pointer . Another method is to use a linear measurement and display as an ammeter. Flow ratio used earlier in the header field of the coil is non-uniform, when the pointer is at infinity, the coil current is strongest just where the magnetic flux density, so even though the measured resistance is large, the current flowing through the coil current rarely, the coil will be larger deflection angle at this time. When the measured resistance is small or is zero, a large current flows, the deflection coil has a smaller magnetic flux density where the deflection angle caused by this current in the coil will not be great. This achieves a non-linear correction. General megohms exemplar head of values shown needs across several orders of magnitude. But when the first linear ammeter in series with the measuring circuit directly to die, at high scale resistance all crowded together, can not distinguish, but also in order to achieve the non-linear correction must be added to the nonlinear element in the measuring circuit. Divert the traffic so as to achieve at a small resistance value. No shunting high resistance, so that the values shown several orders of magnitude. With the development of electronic technology and computer technology, digital form gradually replace the pointer instrument.
Digital insulation resistance measurement technology has been developed, wherein the compression ratio circuit is preferred wherein a measuring circuit voltage ratio and the bridge circuit is a voltage measuring bridge components. Signals of the two bridge outputs are A / D converted into a digital value and then displayed by the single piece through.
tester
insulation resistance products, the charging means and the insulation resistance between the portion (housing) exposed conductive portions of different products, applying a DC high voltage , such as 100V, 250V, 500V, 1000V and the like, a predetermined minimum value of the insulation resistance. Some standards for each kV voltage, insulation resistance of not less than 1MΩ like. In standard household products, usually only a predetermined thermal insulation resistance, the insulation resistance without a predetermined value under normal conditions, insulation resistance values under normal conditions established by the standard corporate itself. If the normal insulation resistance value is low, indicating that there may be some risk or damage to the insulation structure. The insulation resistance of the motor winding housing is low, the windings may be embedded in the slot insulating lines are caused by injury. When using electrical appliances, due to sudden power off or power or other reasons, an overvoltage circuit, the damaged insulation breakdown occurs, causing security or threat to personal safety.
terminology
1, insulation resistance meter (megger) - action of an electrical measuring instrument for direct measurement indicating analogue insulation resistance, expressed in units which MΩ.
2, the measurement end button - insulation resistance meter connected to the terminals to be measured. Measurement of insulation resistance meter side button should be separately marked line side buttons L, ground end button E, G shield glyph end of the button.
3, side button voltage - a voltage between the insulation resistance meter line side and the ground side button button.
4, rated voltage - insulation resistance meter measurement end button at a nominal value of the output voltage of the open circuit condition.
5, the open circuit voltage - insulation resistance meter measuring the output voltage at terminal button Found measured open state.
6, the value of the voltage - insulation resistance meter measurement end button L, E the value of the resistor connected to the measured output voltage value.
where performance
is not only electrically insulated wire wrapped in a plastic polymer material, which is a cable insulation, the sleeve insulator, the inner conduit space, consisting of the motor and general equipment the complete system. Mechanical pressure, and temperature changes can cause pollution of these components deteriorate over time, so that current leakage occurs. Leakage current is generated following questions:
1, is generated when a current is passed through the heat insulating layer, the insulating layer will deteriorate, until the final insulation failure, and will form a fire hazard.
2, the leakage current must be returned to the source, it will flow through any available conductor, conduit, pipe, water or ground return to the source. Such adverse currents create dangerous voltage.
3, the leakage current is not efficient. Leakage current through the insulating layer and not the drive motor, or heat emission, but will still produce consumption.
4, leakage current may cause overcurrent tripping device, so that overheating of motors and transformers.
is the difference between the result of equipment failure caused by electrical insulation, production line downtime. No plant can survive outside the work stoppage was planned. "Customers need to quickly diagnose the problem. No one wants to lost production time, and many customers are eager to know if they are in need of repair equipment or it simply needs to be replaced."
is the same as the electrical system a piping system, the liquid pressure is like voltage, current flow like a liquid, and the like are electrically insulating wall. Insulating prevent leakage of the electrons from the conductor - its role is to use the size of the insulation resistance represented. Effective insulation system has a high resistance value of the resistance, typically greater than a few megohms (MΏ). Poor insulation system having a low insulation resistance.
In order to find leaks in the piping system, you need to pressurize it. Since the water pressure at the highest and most easily found leakage, so you can not turn off the water to check for leaks. However, you can limit water available, so you will not be able to spray around a lot of water when it finds big loophole. Ideally the test pressure is to provide a limited amount of water in the high (but not particularly high). This is electrical insulation testers do.
insulation tester (megger) will be added on a DC voltage insulation system, and measuring the resulting current. Thus it is possible to calculate and display the value of the insulation resistance (insulation level of the current in the wire to be bound, or the extent of preventing the leakage current).
General outputPortable insulation tester (megger) test voltage of 50 V, 100 V, 250 V, 500 V or 1000 V. As may in the pipe system, the aim is not to provide a particularly high pressure (voltage). We hope to have found the leak, but did not want to overstress the system to produce a new leak. Lower voltage for low-voltage systems, such as a telephone, or a network control circuit; high pressure system for testing the insulation of power.
effect test
insulation resistance test system by different components (transformers, switching devices, wires, motors), and the technician can repair the spacer member fails.
technician to test using the test leads and or high insulation resistance between adjacent wires. Two common example is the insulation resistance between the windings of the motor between the test and the motor base, and a phase conductor and grounding line inspection / cage.
before the system is powered by insulation test to verify that it is sound, can improve system performance; insulation test can be found in the manufacturing process problems and equipment defects, and these problems before equipment failure is generally It can not be found. In the EU, this test is mandatory, even for the smallest civil systems as well.
1. A rotatable band switch voltage at any speed, while the power supply is turned on.
2. In the test number selection state, press set key (12) into the status query test results.
3. Press down key (12) to increase and decrease the number of test results. (Corresponding number triad). After
4. Choose a good number, press the test button (10) to enter the number of the test results, press the up and down keys (12) can query the ID test results (current resistance, barrier 15 seconds value, the resistance 60 seconds, 10 minutes resistance, absorption ratio, polarization index).
5. Inquiry is completed, pressing the set key (12) returns the state ready for testing.
6. For queries may query again pressing the set button again (12).
danger to
Do not measure AC / DC voltages above 600v circuits.
Do not place flammability testing, activation may cause an explosion.
If the surface of the instrument or wet hands are wet operation Do not operate the instrument.
when measured, is not in contact with the conductive parts of test leads.
when the test instrument is connected to the short-circuited line, do not press the TEST key.
Never open the measurement.
when the line insulation measurement, not touching the line under test.
Considerations
in front of the measuring resistor, the test circuit must be fully discharged, and completely isolated from the power supply circuit.
If the test pen or damaged power adapter needs to be replaced, must be put on the same type and the same electrical specifications of the test leads and power adapter.
battery power depletion indicator instructions, do not use the instrument. If the instrument is not used for a long time, store battery taken out.
Do, humidity, flammable, explosive environments and strong electromagnetic field store or use the instrument at a high temperature.
with a damp cloth or a cleaning agent for cleaning the instrument, do not use rubbing or solvate.
when the instrument is wet, please after dry storage.