1. Output current: automatically select current (maximum 20A)2. Range: 0~100Ω3. Accuracy: 0.2%±24. Minimum resolution: 0.1μΩ5. Working temperature: -20~40℃6. Ambient humidity: ≤80%RH, no condensation
Product Details
I. Overview
The DC resistance of the transformer is a must-test item for semi-finished products and finished products factory test, installation, handover test and preventive test of the power department in the manufacture of transformers. It can effectively detect the material selection, welding, loose connection of the transformer coil, missing strands, broken wires, etc. Defects and hidden dangers after operation.
In order to meet the needs of rapid measurement of transformer DC resistance, our company has developed HM5002S-10A Three phase transformer DC resistance meter for YN connection winding. The Three phase transformer DC resistance meter realizes three-phase simultaneous power-on, independent current sampling, voltage sampling, and simultaneously measures and displays the three-phase resistance value and three-phase unbalance rate. It greatly shortens the test time of the transformer DC resistance and solves the problem. The long time-consuming test of the DC resistance of each tap winding of the power transformer is only 1/3 of the traditional method.
II. Technical indicators
1. Output current: automatically select current (maximum 20A)
2. Range: 0~100Ω
3. Accuracy: 0.2%±2
4. Minimum resolution: 0.1μΩ
5. Working temperature: -20~40℃
6. Ambient humidity: ≤80%RH, no condensation
7. Power supply: AC220V±10%, 50Hz±1Hz
8. Volume: length 400mm*width 340mm*height 195mm
9. Net weight: 8kg
III. Performance characteristics
1. The instrument has a large output current and the automatic current selection is easy to operate.
2. Three-channel measurement, real-time acquisition, measure three resistance values at the same time, and calculate the three-phase resistance unbalance rate.
3. It can be measured at the same time at three times, or can be measured with a single channel in a traditional way. It also has a temperature conversion function, which is easy to use.
4. It has a complete protection circuit and strong reliability.
5. Built-in calendar clock, 500 sets of data storage, access, and printing functions.
6. You can set the resistance's phase sequence, tap position and other printing information.
7. Industrial plastic case, light weight and easy to carry.
8. With audible discharge alarm, the discharge indication is clear, reducing misoperation.
IV. Safety measures
1. Be sure to read this manual carefully before using this instrument.
2. The operator of the instrument should have common sense in the use of general electrical equipment or instruments.
3. This instrument can be used indoors and outdoors, but it should be used in places such as rain, corrosive gas, excessive dust, high temperature, and direct sunlight.
4. The instrument should avoid severe vibration.
5. The maintenance, care and adjustment of the instrument should be carried out by professionals.
6. After the test is completed, be sure to wait for the discharge alarm to stop before turning off the power, and remove the test line.
7. When measuring the no-load voltage-regulating transformer, you must wait for the discharge indicator and alarm sound to stop before switching gears.
8. During the test, it is forbidden to move the test clip and the power supply line.
V. System introduction
The instrument panel is shown in Figure 1
fig.1
1. Display: color dot matrix liquid crystal display, display menu, test data and record.
2. Buttons: used for the operation of the corresponding functions indicated by the LCD or to return the whole machine to the initial state of power-on.
3. Measuring current output terminals and voltage input terminals: In the three-channel measurement mode, Ia, Ib, Ic, and Io are current output and input channels, and Ua, Ub, UC, and Uo are voltage input channels. In the single-channel measurement mode, I+ and I- are current output and input channels, and U+ and U- are voltage input channels.
4. Power switch and socket: including the power switch of the whole machine, 220V AC power plug (built-in 5A fuse).
5. Grounding: The grounding pole is used for grounding the shell of the whole machine and is a protective ground.
6. USB interface: the interface between the instrument and the U disk
7. RS232 communication interface: the communication interface between the instrument and the host computer
8. Printer: Print resistance value results and test current and other information.
VI. Test and wiring method
1. Single-channel wiring: Connect the tested product to the test terminal of the machine through a dedicated cable, the connection is firm, and the ground wire is connected. Single-channel direct measurement wiring. The resistance between the AO phases can be directly measured as shown in Figure 2
fig.2
2. Three-channel direct measurement wiring, as shown in Figure 3. The resistance values of AO, BO and CO three phases can be directly measured at the same time as shown in Figure 3.
fig.3
VII. Matters needing attention
It must be reset before the test no-load voltage regulating transformer reverse tapping. After the discharge is over, the alarm sound stops before the tapping point can be switched.
1. Before removing the thread, be sure to wait for the alarm to stop after the discharge is over, and then remove the thread.
2. Pay attention when using three channels. Because the initial establishment of the magnetic circuit may take a long time during the first set of data testing, the settling time will be shortened when switching and tapping.
3. When using the magnetic assist method to test, the short contacts of the three wires may have residual current when the wires are removed after the discharge is completed, and may spark and discharge when removed. This is a normal phenomenon.
VIII. Common problems and solutions
1. Cannot test, the buzzer keeps beeping
In this case, first check whether the temperature is protected, and first check whether the fan is working normally. If the fan works normally, you can turn it on without testing, let the fan cool down and then test again.
2. The LCD screen can't light up after booting up
In this case, first check whether the power supply is normal, and then check whether the fuse has been blown, for example, replace it with a new one.
3. The display current drops during current charging
This machine adopts automatic selection of current output mode. In order to achieve stable measurement results, the measured current may be less than the charging current, which is a normal phenomenon.