Overview
A furnace transformer serves an electrical heating or melting process whose duty can differ significantly from a general distribution load. OSTL’s confirmed furnace-transformer categories include arc, induction and ladle applications. The equipment must be matched to the furnace system rather than selected from the process name alone.
Arc, induction or ladle: start with the process interface
A furnace transformer manufacturer needs more than the furnace name or a single MVA figure. For an arc-furnace enquiry, describe the electrical operating cycle and the furnace supplier’s required duty. For an induction-furnace transformer, identify the converter interface and division of supply. For a ladle-furnace enquiry, include the operating schedule and the process team’s electrical requirement. These are specification questions, not a claim that one design serves every furnace.
Ask the furnace or process designer for the input/output voltage schedule, load variation, duty cycle, terminal arrangement and any required regulation or cooling conditions. OSTL reviews the proposed transformer against that brief; do not assume an overload capability or a default tap range.
A furnace quotation should separate network and process duty
A plant may need both a general distribution transformer and a dedicated furnace-duty transformer. Keep the two specifications distinct. Power and distribution transformers address the plant network; the rectifier/converter duty page covers a power-electronic interface. Steel and metal buying questions help organise the project context.
Durgapur, Rourkela, Bokaro and Bhilai are useful destination details for an industrial RFQ, not evidence of an OSTL furnace installation. The approved SAIL Durgapur Township milestone does not establish a furnace reference. State the exact site, specification and purchaser’s documentary requirements.
Typical applications and industries
The following are general duty contexts to discuss, not a list of OSTL customer installations or a guarantee of suitability for every site.
- Arc-furnace electrical supply for metal melting, subject to the furnace designer’s specification.
- Induction-furnace systems, where the converter/power-electronic interface and transformer scope must be established.
- Ladle-furnace electrical duties in metal processing and refining.
- Steel, foundry and metal-processing projects seeking a process-specific transformer discussion.
Define the operating duty
Provide the furnace maker’s electrical schedule, process cycle, expected load variation and short-circuit or overload duty requirements. For an induction system, identify the converter interface. Furnace power, transformer capacity and the required supply arrangement must be reconciled by the project’s electrical and process teams.
General construction considerations
These are design topics, not fixed features promised for every supplied unit. Confirm the construction in the project-specific offer.
- Core and winding design assessed against the electrical and thermal duty.
- Cooling and insulation arrangements selected for the agreed operating cycle and installation.
- Tapping/regulation requirements and terminal interfaces defined by the furnace system.
- Protection, monitoring, enclosure or tank, and accessory requirements agreed in the specification.
Ratings and scope
For these duty-specific products, ratings as per project requirement. The exact kVA/MVA, voltage, construction and operating limits require confirmation in the technical offer. OSTL’s overall power and distribution transformer range is up to 10 MVA and up to 66 kV; dry-type transformers are manufactured up to 3 MVA. These overall ceilings are not a confirmed rating schedule for every special-duty product, and 66 kV must not be applied to dry-type equipment.
BIS, ISO and project-specific documentation
OSTL has held BIS licences in all five major transformer categories since 2020. This is a company credential, not a blanket BIS certification claim for this product line. Ask for the exact licence scope and the standards and documentation applicable to the proposed equipment.
OSTL is ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018 certified; copies available on request. Management-system certification does not establish a particular product rating, enclosure class, efficiency level or test approval. Agree the technical requirements and supporting records in the written offer.
Related equipment and project context
Send a clearer quotation brief
Contact the Kolkata corporate office with the equipment category, duty, rating required, supply/interface voltages, quantity, site conditions and requested dispatch destination. Unknown items can be marked for technical discussion; do not assume a standard configuration.
Landline: 033 4061 3200 · ostltd@hotmail.com. The quotation checklist can help organise the brief.
Losses, winding and cooling: compare the agreed design
For a special-duty transformer, define the actual operating profile and request guaranteed losses at stated conditions. An EE Level 1/2/3 distribution schedule or a BEE star label is not automatically applicable to furnace, rectifier or solar duty. ONAN, if requested for oil-immersed equipment, means oil-natural/air-natural cooling; confirm suitability and the proposed arrangement rather than assuming it is standard.
Copper and aluminium winding options are confirmed. Material selection belongs within the complete electrical and thermal design; neither material by itself guarantees a particular loss, service life or saving. For an oil-filled enquiry, any ONAN requirement must be confirmed in the technical offer; it is not a dry-type cooling label.
Compare offered no-load losses over energised hours and load losses against the actual loading profile at agreed reference conditions. Use the buyer’s tariff and operating inputs; no customer savings or payback is invented here. The EE Level 1 versus 2 versus 3 guide explains the buying questions, and routine-testing guidance helps define acceptance documents.
Manufactured in Howrah. Enquiries through Kolkata.
OSTL’s manufacturing units are Unit 1, Howrah, West Bengal and Unit 2, Sankrail, Howrah. The corporate office is in Kolkata. Send the exact destination, specification and purchaser’s documents; no regional factory, local stock or universal buyer approval is implied.
For eastern India, use the West Bengal, Odisha, Jharkhand and Bihar pages. The Assam/North-East hub provides the enquiry route for Guwahati and wider NE destinations. Nepal, Bhutan and Bangladesh enquiries need the destination and buyer’s documentary requirements; delivery responsibilities, eligibility and commercial feasibility are agreed for that enquiry.
Contact WhatsApp +91 70035 13107, landline 033 4061 3200 or ostltd@hotmail.com. Use the RFQ checklist or discuss repair and after-sales requirements. Online forms do not create a sent enquiry; use the listed contact channels.