Why is it necessary to perform no-load and load tests on a transformer?

The no-load and load tests of a transformer are conducted to assess its performance and operational condition, ensuring that the transformer can operate safely, stably, and efficiently under actual working conditions. These two tests focus on different operational states of the transformer, aiming to understand its core parameters and performance under various load conditions.
1. No-load Test
The no-load test, also called "no-load loss" or "excitation current test," is conducted by applying rated voltage to the primary winding while the secondary winding is open. The main purpose is to evaluate the core performance, no-load losses, and excitation current of the transformer. Specific reasons include:
Core Loss (No-load Loss) Measurement: Under no-load conditions, the losses in a transformer are primarily caused by hysteresis and eddy currents in the core. Measuring these losses helps assess the quality of the core material and the manufacturing process.
Excitation Current Measurement: By measuring the excitation current flowing into the primary side during no-load operation, one can understand the current required to maintain the magnetic flux in the transformer. This helps in analyzing the magnetic properties of the core.
Core Performance Evaluation: The no-load test also helps detect the saturation state of the core and its magnetization characteristics under different voltage levels, ensuring that the core operates within the designed range.
2. On-load Test
The on-load test is conducted by connecting a load to the secondary side of the transformer to assess its performance under actual working conditions. On-load testing can be further divided into short-circuit testing and load loss testing. The main reasons include:
Copper Loss (Load Loss) Measurement: The losses in a transformer under on-load conditions are mainly caused by the current in the windings, which results in copper losses. The on-load test can accurately measure the load losses of the transformer, allowing the assessment of its energy efficiency.
Transformer Efficiency Evaluation: The on-load test allows the calculation of the transformer’s efficiency under different load conditions, helping to understand energy losses and performance under various loads.
Voltage Regulation Characteristic Analysis: The on- load test also evaluates the voltage regulation characteristics of the transformer, i.e., the change in secondary voltage when going from no-load to full-load. This is critical for maintaining voltage stability in the power grid.
Short-circuit Impedance and Voltage Drop: The load test measures the short-circuit impedance and voltage drop of the transformer, which helps assess its response under fault conditions.

JYW6100/6100 (A) Transformer No-load and on-Load Tester/power factor tester

JYW6100 /6100(A)  is widely used in transformer, amorphous alloy transformer, generator, fan motor industries. The instrument ensures the measurement accuracy under the low power factor.   Its exclusive automatic data locking technology with the characteristics of accurate data locking and no manual intervention, makes the work efficiency increased by more than ten times.

Function Introduction

●JYW6100 /6100(A) Transformer No-loads and On-loads tester power factor tester can measure no load loss, load loss, no load current, load current, impedance voltage, zero sequence impedance, line voltage, phase voltage, voltage effective value and average value, average value of three-phase voltage, current value, power, power factor, frequency, 30 square harmonic wave analysis and so on.

●Two watt meter and three watt meter measurement methods.

● Tracking and Locking the data automatically.

●Data storage, data printing, data export to U disk.

●RS485 communication interface, through which the instrument can be operated by computer.

●8 inch color LCD screen, intelligent touch operation.

TECHNOLOGY SPECIFICATION:

Type		JYW6100	JYW6100 (A)
Voltage measuring range		AC10～1000V
Current measuring range		AC0.1～50A	AC0.1～100A
Accurate	Voltage	0.1%±0.005V (Frequency 40～70Hz)
		0.5%±0.005V (Frequency 70～200Hz)
	Current	0.1%±0.0002A (Frequency 40～70Hz)
		0.5%±0.0002A (Frequency 70～200Hz)
	Power	P×0.1%±(U×I×0.02%)±0.05W (P is the power reading, U is the voltage effective reading, I is the current effective reading).
Operation power		AC220V±10%, 50/60Hz
Operation temperature		-20℃～40℃
Relative humidity		≤80%RH, no dew
Volume		L420mm*W320mm*H200mm	L380mm*W360mm*H220mm
Net weight		6.9kg	12kg