How to Choose Induction Furnace Transformer Secondary Voltage: 420V, 500V, 575V, 660V or 750V?
Induction furnace transformer secondary voltage must match the AC input voltage required by the furnace power supply cabinet. It should not be selected only from furnace tonnage or transformer capacity.
Common project voltages include 420V, 500V, 575V, 660V and 750V. The right value depends on the rectifier cabinet, pulse arrangement and approved electrical design. Before production starts, the transformer supplier and furnace supplier should confirm the same voltage on their drawings.
Do Not Choose Secondary Voltage by Furnace Tonnage Alone
A 5-ton or 15-ton furnace does not automatically tell us the transformer secondary voltage. Furnace tonnage describes melting capacity. It does not show the input voltage required by the medium-frequency power supply.
Two furnaces with similar tonnage may use different power supply cabinets. One project may require 500V, while another uses 575V or 660V. The transformer must match the actual cabinet, not a general table found online.
Capacity and voltage are also different questions. Transformer capacity tells us how much apparent power the unit can supply. Secondary voltage tells us the electrical level delivered to the rectifier system. For a broader overview, read how to select a medium-frequency furnace transformer.
Start with the Power Supply Cabinet Nameplate
The safest starting point is the nameplate or technical sheet of the furnace power supply cabinet. Look for its rated AC input voltage and rated frequency. If the cabinet supplier gives a single-line diagram, send that drawing as well.
Confirm whether the stated voltage is line-to-line voltage. Also check whether one transformer feeds one cabinet or several cabinets. A verbal description such as “for a 10-ton furnace” is not enough for final design.
For a replacement, send clear photos of the transformer and cabinet nameplates. Check them together because the furnace system may have been modified.
Match the Voltage with the Pulse Arrangement
The pulse number and secondary voltage must be confirmed at the same time. A 6-pulse system, a 12-pulse system and a 24-pulse system use different winding and phase-shift arrangements.
However, the pulse number does not decide one fixed voltage. A 24-pulse transformer is not automatically a 500V transformer. The voltage still comes from the matched rectifier cabinet and project design.
For a multi-pulse project, the buyer should provide the number of secondary windings, required phase shift and connection diagram. If the furnace supplier has already issued these details, it is better to send the original drawing instead of rewriting the data in an email.
Real Project: 24-Pulse and 500V for India
In one confirmed XINGNIU project for India, the medium-frequency furnace transformer used a 24-pulse design with a 500V secondary voltage. These two parameters were confirmed for the matched furnace power supply system.
The case does not mean that every Indian furnace project needs 500V, or that every 24-pulse transformer uses the same voltage. It shows why the pulse arrangement and secondary voltage must both follow the actual cabinet design.
The capacity, primary voltage, impedance, cooling method, losses, temperature rise and operating result are not included here because they have not been confirmed from the approved drawing or test report. They should be added only after the project record is checked.
Can a Tap Changer Correct the Wrong Secondary Voltage?
Normally, no. A transformer tap changer is used for a limited voltage adjustment around the designed ratio. It is not a practical way to change a transformer designed for 500V into a 575V or 660V unit.
That difference must be handled in the original transformer design. Trying to solve a large mismatch after production can affect the winding design, current level, insulation arrangement and cabinet compatibility.
Approve the voltage before winding material is prepared. Use a signed technical drawing, not only a quotation line.
What to Send Before Ordering
Send the following information when asking for a medium-frequency furnace transformer quotation:
- Grid voltage and frequency
- Required transformer secondary voltage
- Furnace power and furnace tonnage
- Power supply cabinet model and nameplate
- 6-pulse, 12-pulse or 24-pulse requirement
- Number of rectifier cabinets and secondary windings
- Connection and phase-shift diagram, if available
- Required transformer capacity and impedance
- Cooling method, installation environment and altitude
- Destination country and required delivery time
If some data is missing, XINGNIU can review the available nameplates and drawings before confirming the design. Final production should begin only after the main electrical parameters are agreed by both sides.
Ordering an Induction Furnace Transformer from XINGNIU
XINGNIU is a custom transformer factory. We make customized medium-frequency furnace transformers for different capacities, voltages and pulse arrangements. Our design focuses on full rated capacity, low loss and controlled temperature rise.
Normal production time is 15 to 25 days after technical confirmation. The warranty is one year. Actual delivery time depends on the approved design, quantity and production schedule.
To confirm the correct induction furnace transformer secondary voltage, send us the furnace cabinet nameplate, single-line diagram and required pulse number. We will check the information before preparing the technical proposal and quotation.
FAQ
Is 500V standard for every 24-pulse furnace transformer?
No. XINGNIU has a confirmed India project using 24-pulse and 500V, but 500V is not a universal rule. The required voltage must match the power supply cabinet.
Can I select secondary voltage from furnace tonnage?
No. Tonnage alone cannot confirm the cabinet input voltage. Send the cabinet nameplate or electrical drawing.
Can XINGNIU make 420V, 575V, 660V or 750V transformers?
These voltage levels can be handled as customized project requirements. The final voltage, capacity, pulse design and winding arrangement must be confirmed together.
What is the fastest way to receive an accurate quotation?
Send the grid voltage, cabinet input voltage, furnace power, pulse number, transformer capacity, frequency, impedance and destination country. A nameplate photo and single-line diagram can reduce repeated questions.
