Transformer Low-voltage Short-circuit Impedance Tester

The low-voltage short-circuit impedance test is the most direct method to identify whether the transformer is impacted by mechanical force during transportation or installation or short-circuit current during operation, and check whether the winding is deformed. It is of great significance for judging whether the transformer can be put into operation, and it is also a judgment. One of the basis for the disassembly inspection of the transformer.

The transformer low-voltage short-circuit impedance tester is suitable for low-voltage impedance testing of power transformers (single-phase or three-phase) for delivery, handover, pre-test and overhaul. It is a fast testing instrument for checking whether the transformer has winding deformation.

The instrument has single-phase impedance, three-phase impedance, zero sequence impedance (star with neutral point) measurement, as well as empty and load measurement functions.

The instrument has two power modes: internal power supply and external single-phase voltage regulator.

The voltage and current test range of the instrument is wide and the accuracy is high.

It adopts a 7.0-inch touch screen, which is easy to operate.

Built-in large-capacity non-volatile memory can store 160 sets of data.

Built-in high-speed micro thermal printer can print measurement data.

Built-in high-precision clock, real-time display of time.

With U disk storage function.

1. Technical parameters

Voltage range: 15V ~ 500V (PT can be extended), accuracy: ±(reading×0.2% ＋0.05% (range))

Current range: 0.5A～15A (internal), accuracy: ±(reading×0.2% ＋0.05% (range))

0.5A～50A (external) (can be expanded by CT), accuracy: ±(reading×0.2% ＋0.05% (range))

Impedance range: 0～99%

Power factor: 0.02 ＜ cosΦ ＜0.1, accuracy: ±(reading×1.0% ＋0.05% (range))

cosΦ ≥0.1, accuracy: ±(reading×0.5% ＋0.05% (range))

Frequency measurement: 45～65Hz

Resolution: 5 significant digits

Host size: 405mm×330mm×180mm

Host weight: 9.5kg

2. Conditions of use

Ambient temperature: -10℃～50℃

Environmental humidity: ≤85℅RH

Power supply: AC220V ±10%

Schematic diagram of the front panel:

1) Test product test terminals: Ia, Ib, Ic are connected to current test lines, and Ua, Ub, Uc are connected to voltage test lines.

2) P+, P- are external power input terminals.

3) Touch LCD screen.

4) USB interface: used to save data in U disk.

5) On/off button: the power switch of the instrument.

6) Grounding post: the grounding terminal of the instrument shell.

7) Printer: used to print test data.

RS232 communication interface.

Instrument verification wiring: System setting interface, light the "Instrument verification" button (the check box turns green), and then exit the interface, you will hear the relay action sound, this is the relay initialization action before the instrument verification. At this time, connect the test line, click any measurement (such as single-phase short-circuit impedance) button on the main interface, enter the parameter setting interface, modify the parameters to set the lock screen current to the maximum value of 55A (setting method: set the transformer capacity as large as possible, Make the rated current of the transformer greater than 55A, and then set the lock screen current to 55A. To make the lock screen current greater than all the calibration currents, otherwise it cannot be fully verified), click the test button to perform the instrument verification.

Note: Before the test, in the instrument parameter setting interface, select the “external" mode for the “select power supply" item, and the instrument will not output power during calibration. Otherwise, when entering the measurement interface in "internal connection" mode, the internal power supply will output, which will damage the calibration equipment.

1. Please read the manual carefully before using the instrument.

2. During the test, the instrument is grounded reliably to ensure good contact, and it is forbidden to move the test clamp.

3. Pay attention to the low-voltage short-circuit current, the current-carrying capacity of the short wiring should be sufficient, and the contact should be good.

4. If an abnormality occurs during the test of the instrument, please shut down and restart it.

5. When testing the pressure, pay attention to monitor not to exceed the rated voltage and current of the instrument to avoid damage to the instrument. When measuring the sample that exceeds the voltage and current range of the instrument, it can be measured by PT and CT.

6. When measuring the impedance voltage, it should be measured at the rated tap position.