What Tests Should be Done on the Transformer in Operation?

20Dec

What Tests Should be Done on the Transformer in Operation?

 

What Tests Should be Done on the Transformer in Operation?

1. Temperature test
The temperature of transformer is very important for normal operation. Regulations stipulate that the upper oil temperature shall not exceed 85C(i.e. 55C temperature rise). General transformers are equipped with special temperature measuring devices.

2. Load measurement

In order to improve the utilization rate of the transformer and reduce the loss of electric energy, it is necessary to measure the power supply capacity of the transformer in operation. Measurement is usually carried out during peak demand periods of each season and is made directly with a clamp ammeter. The current value should be 70-80% of the rated current of the transformer. If the current value exceeds the rated current, it indicates overload and should be adjusted immediately.

3. Voltage measurement
Regulation requires voltage variation within ±5% of rated voltage. If this range is exceeded, tap should be used to adjust the voltage to reach the specified range. A voltmeter is generally used to measure the terminal voltage of the secondary coil and the terminal voltage of the terminal user.

4. Insulation resistance measurement
In order to keep the transformer in normal operation, insulation resistance must be measured to prevent insulation aging and accidents. Measurement should try to stop the operation of the transformer, the use of shaking the transformer insulation resistance value, the resistance measured is not less than 70% of the value measured before, the selection of shaking meter, low-voltage coil can be used 500 volt voltage level.

 

What Tests Should be Done on the Transformer in Operation?


1. Temperature test

The temperature of transformer is very important for normal operation. Regulations stipulate that the upper oil temperature shall not exceed 85C(i.e. 55C temperature rise). General transformers are equipped with special temperature measuring devices.


2. Load measurement

In order to improve the utilization rate of the transformer and reduce the loss of electric energy, it is necessary to measure the power supply capacity of the transformer in operation. Measurement is usually carried out during peak demand periods of each season and is made directly with a clamp ammeter. The current value should be 70-80% of the rated current of the transformer. If the current value exceeds the rated current, it indicates overload and should be adjusted immediately.


3. Voltage measurement

Regulation requires voltage variation within ±5% of rated voltage. If this range is exceeded, tap should be used to adjust the voltage to reach the specified range. A voltmeter is generally used to measure the terminal voltage of the secondary coil and the terminal voltage of the terminal user.


4. Insulation resistance measurement

In order to keep the transformer in normal operation, insulation resistance must be measured to prevent insulation aging and accidents. Measurement should try to stop the operation of the transformer, the use of shaking the transformer insulation resistance value, the resistance measured is not less than 70% of the value measured before, the selection of shaking meter, low-voltage coil can be used 500 volt voltage level.