Wholesale price safety isolating transformers, manufactured in China, with capacities ranging from 5 kVA to 1000 kVA, can be used as step-up or step-down transformers, converting voltages from single-phase to single-phase and three-phase to three-phase. Whether you are looking for transformer isolation equipment from a reliable Chinese manufacturer, electrical isolation transformers, or any type of custom isolation transformer, let us know your requirements, and we will create a new design to meet your form and function specifications.

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Single phase isolation transformer

Single Phase Isolation Transformer

  1. Dry type
  2. 500 VA-30 kVA
  3. 0V-690V
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3 phase isolation transformer

3 Phase Isolation Transformer

  1. 50 Hz/60 Hz
  2. 4 kVA-300 kVA
  3. 0V-1140V
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Split phase isolation transformer

Split Phase Isolation Transformer

  1. Single phase to split phase
  2. 1 kVA-30 kVA
  3. 110V-480V
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Isolation Transformer Features

Strong Cooling, Low loss

Cold rolled oriented silicon steel sheet with good heat dissipation, low loss core and good magnetization characteristics.

Heat Dissipation Fans

The back of the transformer installed cooling fan, can be strong and effective heat dissipation, reduce the temperature of the machine.

High Temperature Enameled Wire

The Isolation transformer with 180°C high temperature enameled wire, is not easy to oxidation, and has stable performance.

Excellent Insulating Paper

The excellent insulating paper enables the isolation transformer to withstand a 3000V withstand voltage test, enhancing safety.

360 Degree Universal Wheel

Manufactured with removable wheels, the power isolation transformer can rotate 360 degrees, making it more energy-saving when pushed.

Custom Design

The voltage shown is conventional, and all voltage specifications are not shown. Any voltage can be customized according to demand, thanks to our expertise in custom manufacturing. Through our experienced team, we can provide the following special features as a trusted supplier from China:
  • Customized isolation transformers with various input and output voltage levels.
  • Connect the group, adjust the number and position of taps (generally +5%).
  • The allocation of winding capacity, the installation of secondary single-phase winding, the application of rectifier circuit.
  • Whether to require a shell, can be designed and manufactured according to the requirements of users.
  • If there are more than two sets of output voltage, please inform whether group power is needed, if no allocation, please also inform the customer service.

How to step down an isolation transformer from 240V to 120V?

Input Voltage
The transformer takes the 240V/230V input voltage and applies it to the primary winding of the transformer.
Turns Ratio
The turns ratio of the power transformer determines the voltage conversion. In your case, you need a turns ratio of approximately 2:1. This means that the secondary winding will have half the number of turns compared to the primary winding.
The transformer provides electrical isolation between the primary and secondary windings, ensuring that there is no direct electrical connection between the input and output sides.
Output Voltage
As the primary winding is energized with 240V/230V, the secondary winding will produce a reduced voltage of approximately 120V/110V, based on the turns ratio.

How to Use Isolation Transformer Correctly?

1. Determine the transformer specifications: Customize an isolation transformer that meets the power requirements of the equipment you are trying to protect. Consider voltage, current rating and supply frequency, ensure that the transformer is manufactured in compliance with industry standards.
2. Verify the transformer's condition: Please check the 1/3 phase isolation transformer for any signs of physical damage or wear. Since the transformer is shipped directly from the factory in China, please check whether the isolation transformer is intact after receiving the goods.
3. Disconnect the power supply: Safety is paramount; before connecting or disconnecting the isolation transformer, ensure that the power to the connected equipment is switched off and unplugged from the main socket to prevent any electrical hazards.
4. Connect the primary side: The primary side of the isolation transformer is connected to the power source. Connect the input terminals of the transformer to the power supply lines. Ensure that the connections are secure and properly tightened.
5. Connect the secondary side: The secondary side of the transformer is connected to the equipment you want to protect. Connect the output terminals of the transformer to the input terminals of the equipment. Ensure that the connections are secure.
6. Power on the transformer: After all connections have been made, turn on the isolation transformer with care to ensure that the input voltage exactly matches the rated voltage of the transformer.
7. Power on the equipment: Once the isolation transformer has been energised, you can turn on the device connected to its output terminal and then verify if the device is functioning properly. Do not forget to verify that the device is operating correctly.
8. Monitor and troubleshoot: During operation, monitor the equipment for any unusual behavior, such as fluctuations in voltage or irregularities. If you notice any issues, disconnect the equipment from the isolation transformer and troubleshoot the problem.
9. Power off and disconnect: Switch off the device and then the power supply to the transformer. Afterwards, disconnect the appliance from the transformer and finally disconnect the primary side of the transformer from the power supply.

Qualification Certificate


Is an isolation transformer necessary?

Whether an isolation transformer is necessary depends on the specific requirements and circumstances of the electrical system. A custom isolation transformer can provide several benefits, such as electrical safety, noise reduction, and equipment protection. It electrically separates the primary and secondary windings, effectively isolating the output from the input. This isolation can prevent electric shocks, protect sensitive equipment from power surges or voltage fluctuations, and reduce electromagnetic interference. Therefore, in situations where electrical isolation, enhanced safety, or improved equipment performance is desired, an isolation transformer can be considered necessary. However, in many standard residential or commercial applications, where these specific concerns are not present, the use of an isolation transformer may not be required. It is essential to evaluate the unique requirements and potential risks of the electrical system before determining whether an isolation transformer is necessary.

How does an isolation transformer prevent electric shock?

An isolation transformer prevents electric shock by providing electrical isolation between the input and output circuits. It achieves this by using separate primary and secondary windings that are not electrically connected. When electrical power flows into the primary winding, it induces a magnetic field which, in turn, generates a voltage in the secondary winding. Since there is no direct electrical connection between the primary and secondary windings, any potential difference or fault in the secondary circuit does not affect the primary circuit. This isolation effectively prevents the transmission of electrical faults, such as short circuits or ground faults, from the secondary side to the primary side, reducing the risk of electric shock. Additionally, isolation transformers can also help in mitigating common-mode noise and voltage spikes, further enhancing safety in electrical systems.

Does an isolation transformer step up or down?

This China isolation transformer does not step up or step down the voltage. Instead, its primary purpose is to isolate the electrical circuit connected to its output from the circuit connected to its input. It accomplishes this by providing galvanic isolation, which means there is no direct electrical connection between the input and output windings of the transformer.

The input and output windings of an isolation transformer typically have the same number of turns, resulting in a one-to-one turns ratio. As a result, the voltage remains the same on both sides of the transformer.

Isolation transformers are commonly used to provide electrical safety and protect sensitive equipment from electrical noise, voltage spikes, and other disturbances. They are not intended for voltage conversion purposes. If you need to step up or step down voltage, you would need to use a different type of transformer, such as a step-up or step-down transformer.

How to test an isolation transformer?

  • Safety precautions: Ensure you take necessary safety precautions before working with electrical equipment. Make sure the transformer is disconnected from the power source and discharge any residual energy stored in capacitors.
  • Visual inspection: Inspect the transformer for any physical damage such as cracks, loose connections, or burnt components. Ensure that all connections are secure and properly insulated.
  • Continuity test: Using a multimeter, check the continuity between the primary winding (input side) and secondary winding (output side) of the transformer. There should be no continuity between the windings, as the purpose of an isolation transformer is to electrically isolate the input and output.
  • Insulation resistance test: Measure the insulation resistance between the primary winding and the secondary winding using a megohmmeter or insulation resistance tester. This test determines the quality of insulation in the transformer. Refer to the manufacturer's specifications for the acceptable insulation resistance values.
  • Voltage ratio test: Connect the primary winding to a known AC voltage source within the rated voltage range of the transformer. Measure the voltage on the secondary winding and compare it to the expected voltage ratio. The ratio should match the manufacturer's specifications.
  • Load test: Connect a load to the secondary winding and apply the rated voltage to the primary winding. Monitor the transformer's performance by measuring the output voltage and current. Ensure that the transformer can handle the expected load without overheating or voltage drop.
  • Temperature test: Monitor the temperature of the transformer during the load test. Excessive heating may indicate a problem with the transformer, such as insufficient cooling or internal faults.
  • Noise and vibration test: Observe the transformer for any unusual noise or excessive vibration during operation. Unusual sounds or vibrations could be indicative of mechanical or electrical issues.

What are the dangers of an isolation transformer?

  • Electrical shock: Isolation transformers are designed to isolate the input and output circuits electrically, but there is still a risk of electrical shock. If the transformer is not properly installed or maintained, there may be exposed or faulty wiring that can lead to electric shock hazards. It is essential to follow proper safety procedures and ensure the transformer is installed by a qualified professional.
  • High voltage transients: Isolation transformers can be susceptible to high voltage transients or surges. If there is a sudden increase in voltage on the primary side, it can induce a corresponding surge on the secondary side. These voltage transients can damage sensitive equipment connected to the secondary side of the power transformer. Surge protection devices should be used in conjunction with isolation transformers to mitigate this risk.
  • Overheating: Isolation transformers can generate heat during operation. If the transformer is not properly ventilated or if it is overloaded, it can lead to excessive heat buildup. Overheating can damage the transformer and pose a fire hazard. It is crucial to ensure that the transformer is adequately sized for the load and that it is installed in a well-ventilated area.
  • Insulation breakdown: Over time, the insulation materials used in isolation transformers can degrade due to factors such as heat, moisture, or age. If the insulation breaks down, it can lead to short circuits, electrical arcing, and potential fires. Regular inspection and maintenance of the transformer are necessary to identify and address any signs of insulation degradation.
  • Electromagnetic interference (EMI): Isolation transformers can help reduce EMI between the input and output circuits. However, if the transformer is not properly shielded or if there are design flaws, it may introduce its own EMI. This interference can affect nearby sensitive equipment or disrupt communication signals. High-quality isolation transformers with proper shielding should be used to minimize the risk of EMI.

It's important to note that these dangers can be mitigated by following safety guidelines, using properly rated equipment, and ensuring regular maintenance and inspections of the isolation transformer. It is advisable to consult with a qualified electrician or professional when installing or working with isolation transformers to minimize risks and ensure safe operation.

Can an isolation transformer improve the quality of electrical power?

Yes, an isolation transformer can improve the quality of electrical power in certain situations. An isolation transformer is a type of transformer that provides electrical isolation between the input and output windings. It has a primary winding and a secondary winding, which are not electrically connected but are magnetically coupled.

Here are some ways in which an isolation transformer can improve the quality of electrical power:
  • Electrical Isolation: The primary purpose of manufacturing an isolation transformer is to provide electrical isolation. It physically separates the input and output sides of the transformer, preventing the flow of direct current (DC) and reducing the transmission of electrical noise and transients. This isolation helps to protect sensitive equipment from electrical disturbances and reduces the risk of ground loops.
  • Voltage Regulation: Isolation transformers can provide voltage regulation by compensating for voltage sags and surges. They have the ability to boost or buck the voltage depending on the input and output configurations. By maintaining a stable voltage level, they can help protect equipment from voltage fluctuations that could affect their performance or cause damage.
  • Ground Fault Protection: Isolation transformers can provide protection against ground faults. If a fault occurs in the equipment connected to the secondary side of the transformer, the fault current does not flow back to the primary side. This feature enhances safety and minimizes the risk of electrical shock.
  • Noise Reduction: The isolation provided by an isolation transformer helps reduce common mode noise. Common mode noise is unwanted electrical noise that appears on both the live and neutral wires relative to ground. By breaking the electrical connection between the input and output sides, an isolation transformer prevents the propagation of common mode noise and improves the overall quality of the power supply.
  • Surge Suppression: Isolation transformers can offer some level of surge suppression. They have the ability to absorb and suppress voltage spikes or surges that may occur in the power supply. While isolation transformers are not designed specifically for surge protection, they can provide a certain degree of protection against moderate voltage transients.

It's important to note that while isolation transformers can provide certain benefits, they may not be suitable or necessary for all applications. The specific requirements of the electrical system and the equipment being used should be considered when determining whether an isolation transformer will be beneficial in improving power quality.

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