Quick answer
A transformer quotation stays usable only when its technical baseline, included accessories, documents, delivery assumptions and validity date are visible. When any of those inputs changes, ask for a marked revision and a clear list of price, design, test and schedule effects. Do not treat the original price as transferable to a different voltage, connection, enclosure, accessory set or delivery scope. A short change register lets the buyer compare revisions and release the purchase order against one approved configuration.
Define what the original quotation actually covers
The phrase “quotation valid for 30 days” does not explain what is being held. Start by saving the issued quotation, the data sheet, the single-line diagram and every referenced attachment as one baseline. Record the revision, issue date, currency and commercial assumptions with the technical files.
| Quotation area | Questions to freeze before comparison | Evidence to retain |
|---|---|---|
| Electrical duty | Are the rated power, primary and secondary voltages, frequency, phase, vector group and impedance unchanged? | Approved data sheet and single-line diagram |
| Installation and environment | Are indoor/outdoor use, altitude, ambient temperature, cooling, noise and enclosure conditions unchanged? | Site data and installation assumptions |
| Terminals and accessories | Are bushings or cable boxes, tap equipment, neutral, temperature devices, fans, valves and surge accessories included? | Accessory schedule and terminal drawing |
| Tests and documents | Are routine tests, witnessed tests, drawings, manuals, certificates and language requirements the same? | Document and inspection schedule |
| Delivery scope | Are packing, loose parts, destination, unloading, storage and installation responsibilities unchanged? | Delivery boundary and logistics assumptions |
The list is a comparison control, not a promise that a supplier will hold an unchanged price in every market. The supplier and buyer still need to agree the commercial terms for the project.
Separate a clarification from a specification change
Not every question requires a new design. A clarification explains an existing assumption, while a change modifies the equipment or the supplier's work. Ask the supplier to classify each request before accepting a revised total.
| Buyer request | Likely treatment | What the revised quotation should show |
|---|---|---|
| Correct a drawing typo without changing the approved duty | Document correction | New revision and confirmation that price and design are unchanged |
| Add a temperature indicator or monitoring contact | Accessory change | Device identity, wiring, tests, documents and price delta |
| Change voltage, frequency, impedance or vector group | Engineering change | New design basis, rating checks, losses, tests and delivery impact |
| Replace a bushing with a cable box or alter the terminal side | Interface change | Connection drawing, dimensions, accessories and installation boundary |
| Add a destination, packing or unloading requirement | Delivery change | Updated logistics scope, responsibility and commercial assumptions |
IEC 60076-1 includes a functional method of specification and treats transport and other transformer requirements as part of the general specification context. Use the standard as a framework for a complete input set, then ask the supplier to identify the project-specific consequences. The IEC 60076-1 publication does not set your price, delivery promise or local utility approval.
Use a revision register before the purchase order
Create one row for every change rather than exchanging untracked email paragraphs. The minimum fields are original value, proposed value, reason, request owner, technical effect, commercial effect, approval and revision number. Keep a separate “open” state when an item is not yet approved.
For example, an industrial project may first request an oil-immersed distribution transformer with a defined terminal arrangement. The project later adds a remote temperature alarm and changes the cable approach. The buyer should receive a revised accessory schedule and terminal drawing, not only a new total. If the cable approach changes the bushing position or enclosure, the supplier must identify the resulting dimension, testing and installation review.
Schneider Electric's transformer installation manual illustrates why assembly and site assumptions matter: components such as bushings, conservators, radiators and other accessories can have their own transport or installation instructions. This is a manufacturer-specific example, not a Jinxing configuration or a universal accessory list. See the Schneider transformer manual.
Revalidate the quotation in four steps
1. Mark the baseline. Send the original quotation number, data sheet revision and the exact changed lines. 2. Request a delta. Ask for changed drawings, accessory lists, test requirements, exclusions, price and schedule effects. 3. Close technical review. The project engineer confirms voltage, interfaces, protection, installation and documentation; unresolved assumptions remain open. 4. Release one order basis. The purchase order references the approved quotation revision and attachments. Superseded totals and drawings are retained for traceability but are not used for manufacturing.
This sequence also protects the buyer when the project is delayed. A date extension should confirm whether material costs, currency, freight, storage, raw-material commitments or design changes affect the offer. It should not silently extend an old technical baseline.
For the starting information, use the transformer quotation page and compare the actual equipment family on the oil-immersed transformer page or dry-type transformer page. The existing transformer quotation requirements guide covers the initial RFQ; this article focuses on controlling changes between that RFQ and the order. A supplier should receive the approved revision before the buyer asks for a final manufacturing release. Use the project enquiry page for a configuration-specific review.
RFQ and revision checklist
- Quotation number, issue date, validity date and currency.
- Approved electrical data sheet, single-line diagram and site conditions.
- Included and excluded accessories, terminals, loose parts and control wiring.
- Test, inspection, drawing, manual, certificate and language requirements.
- Packing, destination, unloading, storage and installation responsibilities.
- A marked change register with technical, commercial and schedule impacts.
- One approved quotation revision referenced by the purchase order.
FAQ
Does an expired quotation always require a completely new transformer design?
No. It requires a review of the original assumptions and current commercial conditions. The supplier can confirm which technical documents remain applicable and whether a revised price, schedule or design review is required.
Can a buyer add accessories after accepting the transformer price?
Ask for a written revision. An accessory can change wiring, terminals, enclosure space, tests, documents and delivery, so the original total should not be assumed to include it.
Is a quotation revision the same as a purchase-order change order?
No. A quotation revision is the supplier's updated offer for review. The purchase order or contract change process determines what is authorized for manufacture and which revision governs the work.