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    40 kVA Isolation Transformer, 3 phase, 240 Volt to 480 Volt

    5 out of 5 based on 2 reviews | Write a review
    40 kVA isolation transformer is designed to step down 3 phase voltage 480V to 240V or step up 240V to 480V, aluminium/copper winding material, and widely used in various power supply sites with frequency 50Hz or 60Hz.
    30-day Returns
    Delivery date: 10-20 days

    High quality and safety isolating transformers particularly suited for use in control circuits and general applications such as mechanical and electronic equipment, precision machine tool, CNC machine tool, lighting, etc.

    40 kVA Isolation Transformer Features

    • Dry air self cooling of cooling mode.
    • three phase unit with 40 kVA power rating.
    • Step down or step up voltage 240V with 480V.
    • Have a minimum 1 year warranty.


    Basics Model ATO-SG40KVA
    Phase 3 phase
    Capacity 40 kVA
    Weight of Aluminium Wire Transformer Open type: 180kg
    Protected type: 215kg
    Weight of Copper Wire Transformer Open type: 190kg
    Protected type: 220kg
    Technical Parameters Primary Voltage 240V (Optional: 120V/ 190V/ 208V/ 220V/ 230V/ 240V/ 380V/ 400V/ 415V/ 480V)
    Secondary Voltage 480V (Optional: 120V/ 190V/ 208V/ 220V/ 230V/ 240V/ 380V/ 400V/ 415V/ 480V)
    Voltage Convert Three phase to three phase
    Frequency 50Hz / 60 Hz
    Winding Material Aluminium/Copper wire (Optional)
    Work Efficiency ≥95%
    Insulation Resistance ≥50 MΩ
    Electrical Strength 3000V AC/1 min
    Noise <35-65dB (1 meter)
    Insulation Grade H level
    Wiring Mode Dyn11
    Cooling Mode Dry type air cooling
    Overload Capacity Allow more than 1.2 times rated load to work for up to 4 hours
    Enclosure Protection Grade IP 24
    Certificate CE, ISO
    Warranty 12 months
    Working Environment Temperature -15℃~+40℃
    Humidity ≤90%RH, without condensation
    Altitude <1000m, non corrosive gas and conductive dust


    Transformer can only convert voltage and CANNOT convert frequency.
    Transformer CANNOT convert single phase voltage to 3 phase voltage.
    Input/output voltage, power rating and whether with shell of all transformers, can be customized according to clients' requirements.

    3 Phase Isolation Transformer Schematic Diagram

    ATO isolation transformers schematic diagram

    3 Phase Isolation Transformer Details

    3-phase isolation transformer details

    40 kVA Isolation Transformer Installation Dimension

    3 phase isolation transformer dimension

    Aluminium Wire Transformer Size Copper Wire Transformer Size
    Open type: a*b*c=500*330*480mm Open type: a*b*c=440*350*420mm
    Mouting size: d*e=340*190mm Mouting size: d*e=300*200mm
    Protected type: A*B*C=455*660*710mm Protected type: A*B*C=420*610*610mm

    Tips: Difference between isolation transformer and autotransformer

    The main function of isolation transformer is to isolate the electrical equipment and Grid, it has no direct electrical connection with electric equipment and power supply and is used for safety situations or occasions with high anti-interference requirement, etc.

    Isolated type structure uses more materials and the cost is high, in addition to changing the voltage, it can also electrically isolate the input winding and output winding, input/output and zero line is also isolated to avoid the danger of touching the charged body at the same time. Besides, with the function of filter performance and high security, isolation transformer can also restrain various interferences.

    Autotransformer is a self-coupling transformer, its structure is relatively simple and the cost is low, input/output and zero line are shared to use. The secondary side of the transformer is a part of the primary side, the primary and secondary side share a same winding, the two coils make use of the electric current difference to cut the magnetic line and realize voltage transformation. It is generally used to boost voltage of the direct current, the output and input of the transformer has direct electrical connection and safety performance is poor.

    Autotransformer is similar to three-terminal adjustable resistance. Because the voltage of direct current cannot be directly boosted and it needs to go through the electronic components, autotransformer is generally used to adjust the voltage of the equipment.

    How to Test Step Up & Step Down Isolation Transformer?

    Need more detail of ATO isolation transformer? Here is a good explanation about it in this video. To test the accuracy of the transformer voltage, we take a 3000 VA single phase 220V iuput to 110V output isolation transformer as an example.

    Existing reviews of 40 kVA Isolation Transformer, 3 phase, 240 Volt to 480 Volt
    Would like to purchase 10 of the 40kVA isolation transformer
    Hi, I was wondering if you have someone locally in Des Moines Iowa where I can purchase your transformers? We potentially will be purchasing 10 of the ATO-T-SG40KVA.
    From: Randy Hommer | Date: 11/07/2019
    Was this review helpful? Yes No (0/0)
    ATO Responded
    Don't have distributor in Iowa, but you can order from us directly. And we ship the transformer to your address free of charge.
    Excellent step-up or step-down isolation transformer
    Excellent step-up or step-down isolation transformer, although big and heavy. This unit is copper winding which appears to be quality and will last quite a while. As far as the value of the product is concerned, I'm very pleased with the purchase.
    From: Terry Phan | Date: 14/07/2018
    Was this review helpful? Yes No (0/0)
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