A specification-led enquiry
Dry-type and oil-filled transformers should be compared against the real installation. The absence of insulating oil in the active part does not remove the need to evaluate ventilation, enclosure, environmental exposure, electrical protection and access for maintenance. A label such as “indoor” is not a complete installation specification.
OSTL manufactures dry-type transformers up to 3 MVA. Voltage, insulation system, construction, enclosure and accessories are confirmed against the project specification. The 66 kV ceiling stated for the combined power and distribution range must not be applied to this dry-type line without separate confirmation.
Describe the space, not just the rating
Share the room layout, ventilation strategy and environmental conditions. Equipment-room heat removal and clearances are project-design responsibilities, not dimensions that can be inferred from an illustrative image.
Identify dust, moisture, contamination, access restrictions and any specific enclosure requirement. “Dry type” alone does not confirm a protection rating or suitability for every exposed location.
If a particular insulation process, fire-performance classification or monitoring arrangement is required, state it explicitly. This website does not confirm cast-resin, VPI, insulation class, temperature rise or enclosure ratings for a specific OSTL model.
Confirmed range. Details to request.
| Item | What to provide or confirm |
|---|---|
| Required rating | kVA or MVA within the confirmed up-to-3-MVA line; exact design feasibility to confirm. |
| HV / LV requirements | Voltage, phase, frequency and system conditions; no default voltage is published here. |
| Construction and insulation | Any specified insulation process, class or performance category, with evidence and availability to confirm. |
| Enclosure and environment | Required enclosure protection, ventilation, ambient temperature, altitude, dust and moisture exposure. |
| Winding material | Copper or aluminium preference, with selection confirmed for the project design. |
| Interfaces and monitoring | Cable or bus connection details, layout constraints and requested protection/monitoring functions. |
| Performance and acceptance | Agreed losses, impedance, temperature conditions, standards and acceptance documentation. |
| Commercial and installation scope | Quantity, location, requested timeline, transport, unloading and responsibility for installation. |
Copper, aluminium and configuration choices
OSTL offers copper and aluminium windings, with the product-specific material and design confirmed on enquiry. For a dry-type enquiry, also ask how the proposed insulation and enclosure arrangement addresses your installation conditions. A picture of a coil or enclosure is not evidence of a particular insulation system or fire-performance classification.
Compare alternatives without blanket claims
Dry-type equipment is not automatically maintenance-free, universally fireproof or always lower-cost than an oil-filled alternative. Compare the total installation requirements, operating conditions, agreed losses, access needs and scope of supply. The right choice should be agreed with the project’s qualified electrical engineer.
Request confirmation of the applicable product standard, test schedule, drawings and any project-required certificates. The general company references to BIS licensing and IS 1180 / IS 2026 do not by themselves establish certification of a particular dry-type design. Exact applicability must be checked for the product being quoted.
Useful next steps
Prepare a useful quotation brief
A practical technical and commercial checklist, plus a copyable/downloadable template.
↗SELECTION GUIDEDry type or oil filled?
Compare the installation, cooling, environmental and maintenance questions before choosing.
↗RATING ENQUIRIESTransformer rating enquiries
Browse rating interests across product lines. Dry type remains up to 3 MVA; higher ratings are not dry-type offers.
↗Questions before you enquire
What dry-type capacity is confirmed?
OSTL manufactures dry-type transformers up to 3 MVA. The exact rating, voltage and configuration must be confirmed against your project brief.
Does the power/distribution 66 kV limit also apply to dry type?
No such claim is made here. Dry-type voltage capability is to be confirmed separately for the requested design.
Is cast-resin construction or an enclosure rating guaranteed?
No. Share the required insulation system, enclosure and environment; OSTL must confirm the proposed configuration and supporting documentation.