Use this guide to prepare a transformer enquiry, from 63 kVA to 10000 kVA (10 MVA). The required construction, HV/LV voltage, load profile, system conditions and installation requirements determine the design that should be discussed. kVA measures apparent power; it is not a fixed kW conversion or a complete load assessment.
Requested target/enquiry ratings only. These entries are not confirmed stocked units, approved models, published standard designs or price offers. Exact technical feasibility, availability and product-specific BIS licence applicability must be confirmed by OSTL.
Confirmed company boundaries: power and distribution transformers up to 10 MVA and up to 66 kV; dry-type transformers up to 3 MVA. Do not extend the 66 kV statement to dry type or infer that all rating/voltage combinations are available. The 5 MVA and 10 MVA interests below are not dry-type offers.
Jump to a short specification focus, then open the enquiry form with the rating filled in. Values of 1000 kVA and above also show the equivalent MVA notation.
The specification every enquiry needs
The notes below highlight different questions to settle; they are not exclusive uses or guaranteed capabilities of any rating. Discuss the complete brief with the project engineer and OSTL.
Electrical duty: required kVA/MVA, transformer type, HV/LV voltage, phase, frequency and load/duty information.
Design and performance: winding preference, any cooling/core requirements, specified losses, impedance, temperature limits and their reference conditions. Copper and aluminium windings are confirmed; ONAN and CRGO remain options/requirements to confirm.
Acceptance: applicable standards and actual product-specific BIS scope, approved drawings, agreed routine-test documents and any separately requested inspection.
Project scope: quantity, service conditions, interfaces, delivery state/country, requested dispatch timeline and packing/handling responsibilities.
Use the quotation checklist and blank RFQ worksheet for the full brief. The online enquiry form does not transmit submissions; use the listed phone, email or WhatsApp for an actual enquiry.
REQUESTED ENQUIRY INTEREST
63 kVA transformer enquiry
Start with the operating load
For a 63 kVA enquiry, separate connected equipment ratings from the expected operating load. Ask the project engineer to describe duty, operating hours and any demand information available; the rating alone does not establish suitability.
Provide the load schedule and any existing transformer nameplate for a replacement.
Confirm the required HV/LV voltage and site conditions rather than adopting assumed values.
Technical suitability, licence scope and commercial terms require confirmation. No stock, fixed specification or price is stated.
REQUESTED ENQUIRY INTEREST
100 kVA transformer enquiry
Describe demand and diversity
A 100 kVA enquiry should identify which loads operate together and how demand has been assessed. A simple total of equipment nameplates is not a completed transformer-selection calculation.
Include the engineer’s diversity and phase-loading assumptions where relevant.
State any future load allowance separately from the present requirement.
Technical suitability, licence scope and commercial terms require confirmation. No stock, fixed specification or price is stated.
REQUESTED ENQUIRY INTEREST
160 kVA transformer enquiry
Check replacement interfaces
For a 160 kVA replacement interest, include the existing nameplate, drawings and reasons for replacement. Matching the rating does not establish that terminals, protection or the available installation space will match.
Provide cable or busbar interfaces, access restrictions and any required footprint drawing.
Have the project engineer confirm electrical compatibility and the applicable performance schedule.
Technical suitability, licence scope and commercial terms require confirmation. No stock, fixed specification or price is stated.
REQUESTED ENQUIRY INTEREST
200 kVA transformer enquiry
Identify changing or starting loads
For a 200 kVA enquiry, describe relevant load changes, starting duties or non-linear loads so the project engineer can specify the operating conditions. Do not infer a permissible motor size or starting performance from the kVA label.
Include any project requirements for voltage regulation and load duty.
Request confirmation of the proposed design against the supplied system information.
Technical suitability, licence scope and commercial terms require confirmation. No stock, fixed specification or price is stated.
REQUESTED ENQUIRY INTEREST
400 kVA transformer enquiry
Separate current demand from expansion
A 400 kVA enquiry is clearer when present demand and planned expansion are documented separately. Explain the basis of any spare capacity requested; a larger nominal rating is not automatically the best selection.
Provide the current load profile and the timing of any planned additions.
Ask for the agreed performance and commercial scope, including exclusions.
Technical suitability, licence scope and commercial terms require confirmation. No stock, fixed specification or price is stated.
REQUESTED ENQUIRY INTEREST
500 kVA transformer enquiry
Compare the same technical schedule
For a 500 kVA interest, compare quotations against an identical brief. Differences in specified losses, accessories, testing or delivery responsibilities can make headline prices misleading.
State the required performance values and reference conditions when specified by your engineer.
Ask each offer to identify deviations, included documents and the requested dispatch destination.
Technical suitability, licence scope and commercial terms require confirmation. No stock, fixed specification or price is stated.
REQUESTED ENQUIRY INTEREST
630 kVA transformer enquiry
Make the installation environment explicit
A 630 kVA enquiry should describe ambient conditions, altitude, indoor/outdoor location and exposure to dust or moisture. The manufacturer needs the actual site brief; performance at unconfirmed conditions should not be assumed.
Include the specified service conditions and any space or ventilation constraints.
Confirm construction, cooling and any enclosure requirements for the proposed design.
Technical suitability, licence scope and commercial terms require confirmation. No stock, fixed specification or price is stated.
REQUESTED ENQUIRY INTEREST
800 kVA transformer enquiry
Define terminations and site access
For an 800 kVA enquiry, show how the transformer will connect to the surrounding installation. Cable entries, busduct interfaces, earthing and handling access belong in the enquiry rather than being left until delivery.
Share the relevant interface drawings and project protection requirements.
Clarify unloading, positioning and installation responsibilities within the commercial scope.
Technical suitability, licence scope and commercial terms require confirmation. No stock, fixed specification or price is stated.
REQUESTED ENQUIRY INTEREST
1000 kVA / 1 MVA transformer enquiry
Express the duty as well as the rating
1000 kVA equals 1 MVA: these are two ways to express the same apparent-power rating. Neither is a fixed kW output statement. Include the load profile and the project engineer’s duty assumptions in the enquiry.
Confirm the selected transformer type and the full electrical specification.
Describe any continuity, standby or operating arrangements that affect the project brief.
Technical suitability, licence scope and commercial terms require confirmation. No stock, fixed specification or price is stated.
REQUESTED ENQUIRY INTEREST
1250 kVA / 1.25 MVA transformer enquiry
Choose the construction for the installation
1250 kVA equals 1.25 MVA. State whether the project calls for dry-type or oil-filled construction, or ask OSTL to discuss the requirements with the project engineer. A rating by itself does not select the construction.
Provide indoor/outdoor location, ventilation or cooling requirements and maintenance-access constraints.
For a dry-type interest, confirm the actual insulation, enclosure and project performance requirements; these are not assumed standard features.
Technical suitability, licence scope and commercial terms require confirmation. No stock, fixed specification or price is stated.
REQUESTED ENQUIRY INTEREST
1500 kVA / 1.5 MVA transformer enquiry
Keep the exact requested rating
1500 kVA equals 1.5 MVA. Keep this requirement distinct from a 1600 kVA enquiry unless the project engineer has approved an alternative. Do not carry over protection, dimensional or performance assumptions from a nearby rating.
Identify whether alternatives are permitted and what would need technical approval.
Request a completed technical schedule for the exact design offered.
Technical suitability, licence scope and commercial terms require confirmation. No stock, fixed specification or price is stated.
REQUESTED ENQUIRY INTEREST
1600 kVA / 1.6 MVA transformer enquiry
Document compatibility requirements
1600 kVA equals 1.6 MVA. If the enquiry involves operation alongside an existing transformer, have the project engineer specify the compatibility requirements rather than assuming that similar ratings can operate in parallel.
Include the existing nameplate and the relevant system/connection information.
Request confirmation of the applicable design, interfaces and performance schedule.
Technical suitability, licence scope and commercial terms require confirmation. No stock, fixed specification or price is stated.
REQUESTED ENQUIRY INTEREST
2000 kVA / 2 MVA transformer enquiry
Agree the basis of performance comparison
2000 kVA equals 2 MVA. Compare proposed designs using the same duty and agreed loss/reference conditions. Copper or aluminium winding selection is a design discussion, not a substitute for the complete performance specification.
Supply any specified losses, impedance and temperature requirements with their reference conditions.
Ask OSTL to confirm material selection, the technical schedule and scope of supply.
Technical suitability, licence scope and commercial terms require confirmation. No stock, fixed specification or price is stated.
REQUESTED ENQUIRY INTEREST
3000 kVA / 3 MVA transformer enquiry
Respect the dry-type range boundary
3000 kVA equals 3 MVA, the confirmed upper rating for OSTL’s dry-type product line. This does not confirm every voltage, insulation system or configuration at that rating. An oil-filled interest also needs its own project-specific review.
State the required construction and HV/LV voltage explicitly; do not apply the overall 66 kV company range to dry-type products.
Ask OSTL to confirm the exact design, applicable standards/licence scope and agreed testing documents.
Technical suitability, licence scope and commercial terms require confirmation. No stock, fixed specification or price is stated.
REQUESTED ENQUIRY INTEREST
5000 kVA / 5 MVA transformer enquiry
Prepare a power/distribution project brief
5000 kVA equals 5 MVA. This is a power/distribution enquiry interest within the overall company range, not a dry-type offer. OSTL’s confirmed dry-type range stops at 3 MVA; the exact 5 MVA configuration still requires confirmation.
Include network duty, the required HV/LV voltage, protection interfaces and project performance requirements.
Agree drawings, inspection/testing scope and any separately requested witnessing before ordering.
A 5000 kVA OSTL transformer installed at site: real photograph.
Technical suitability, licence scope and commercial terms require confirmation. No stock, fixed specification or price is stated.
REQUESTED ENQUIRY INTEREST
10000 kVA / 10 MVA transformer enquiry
Confirm the complete upper-range design
10000 kVA equals 10 MVA, the upper rating of OSTL’s confirmed overall power and distribution range. The company also states a voltage range up to 66 kV; those two limits do not establish that every rating/voltage combination is available. This is not a dry-type offer.
Request technical confirmation of the complete rating, voltage, duty and configuration.
Provide site access and handling constraints, delivery destination, packing requirements and requested dispatch timeline.
Technical suitability, licence scope and commercial terms require confirmation. No stock, fixed specification or price is stated.
Questions about rating enquiries
Are these confirmed stocked or BIS-approved models?
No. These are requested target/enquiry ratings, not a model catalogue or stock list. OSTL must confirm the exact design, availability and applicable product-specific BIS licence scope.
Can I request a 5 MVA or 10 MVA dry-type transformer?
Those ratings are outside OSTL’s confirmed dry-type range of up to 3 MVA. The 5 MVA and 10 MVA interests here are power/distribution discussions only; exact designs remain to confirm.
How do kVA and MVA relate?
1 MVA equals 1000 kVA. For example, 1250 kVA is 1.25 MVA, 1500 kVA is 1.5 MVA and 1600 kVA is 1.6 MVA. The notation does not change the required technical specification or establish a fixed kW output.
Before a rating-specific offer is confirmed
A rating-specific offer needs a verified technical schedule. Ask OSTL to confirm the exact type/rating, voltage and basic system details, construction and materials, applicable standard/licence scope, supported performance data and an approved dimensional drawing or datasheet. Availability and dispatch statements must also be supported.
Keep unconfirmed values clearly marked in your enquiry until the technical and commercial offer is agreed. Use the existing regional pages for location context and the relevant product page for the manufacturing range.
