Datasheet and ratings
Identify the proposed model and the electrical ratings that the document must cover.
Request for your projectHEAKOR / Buyer knowledge
Transformer buying,
made clearer.
Practical transformer buying guides for the decisions before a purchase.
Prepare the specification, check document scope and compare proposals on the same basis.
Choose your next task
What are you working on?
01 ↗
Choose a product family
Compare the main transformer arrangements.
02 ↗Prepare your specification
Collect the electrical, site and supply requirements.
03 ↗Send a complete RFQ
Use a practical checklist before requesting prices.
04 ↗Check certificate scope
Match the certificate to the model and rating.
05 ↗Plan a replacement
Record the existing equipment and site constraints.
06 ↗Compare quotations
Check technical scope, documents and commercial terms.
Start here / Procurement essentials
A better enquiry makes a better starting point.
Bring the electrical ratings, site conditions, destination, quantity and required documents together before requesting a quotation.
Open the transformer RFQ checklist- 01Identify the equipment and application
- 02Define electrical and site requirements
- 03List documents and approval needs
- 04Clarify quantity, destination and timing
The guide library
Read. Check. Prepare.
Use these guides to prepare questions for your technical team and supplier. Project documents govern final selection.
18 Oct 2026
Pad-Mounted Transformer Fuse Coordination: Three-Phase Guide
Pad-mounted transformer fuse coordination needs traceable fuse identities, time-current curves, study inputs and an engineering decision. Use this guide to d...
Read the guide
17 Oct 2026
Pad-Mounted Transformer Enclosure Integrity: Evidence Before Order
Pad-mounted transformer enclosure integrity requires evidence matched to the offered three-phase cabinet. Review doors, barriers, optional openings and desig...
Read the guide
17 Oct 2026
Substation Transformer Short-Circuit Withstand: IEC Evidence Review
Substation transformer short-circuit withstand evidence should address thermal and dynamic duty. Review reference-design applicability, project fault conditi...
Read the guide
17 Oct 2026
Pole-Mounted Transformer Mounting: Single-Phase Drawing Review
Pole-mounted transformer mounting for a single-phase unit requires a drawing comparison before order. Check hangers, mating dimensions, weight, hardware resp...
Read the guide
16 Oct 2026
Transformer Fluid Change: Mineral Oil to Natural Ester
A transformer fluid change before order affects more than the liquid designation. Use this U.S. procurement checklist to review the proposed natural ester, m...
Read the guide
16 Oct 2026
Dry-Type Transformer Vacuum Breaker Interface: Order Checklist
A dry-type transformer vacuum breaker interface needs a defined equipment combination, connection arrangement and technical reviewer. Use this U.S. EPC check...
Read the guide
16 Oct 2026
Dry-Type Transformer Fan-Assisted Duty: Pre-Order Checklist
Define dry-type transformer fan-assisted duty before accepting the higher kVA figure. This guide helps UK EPC buyers separate continuous demand from temporar...
Read the guide
15 Oct 2026
Dry-Type Transformer Electrostatic Shield: Evidence Checklist
Review a dry-type transformer electrostatic shield through separate construction and attenuation evidence. Use this checklist to compare disturbance modes, f...
Read the guide
15 Oct 2026
Dry-Type Transformer Primary Taps: Voltage and kVA Checklist
Specify dry-type transformer primary taps with a position-by-position voltage and capacity schedule. This guide helps U.S. industrial buyers compare full-cap...
Read the guide
15 Oct 2026
Transformer Oil BDV Report: Test Method Acceptance Checklist
A transformer oil BDV report needs a named method, liquid identity, sample stage and agreed acceptance criterion. Use this procurement checklist to compare t...
Read the guide
14 Oct 2026
Transformer Shipment Impact Indicators: Dry-Type Acceptance
Transformer shipment impact indicators provide handling evidence, not an internal condition diagnosis. Distinguish visual status, QR observations and logger ...
Read the guide
14 Oct 2026
Liquid-Filled Transformer Pressure Devices: RFQ Scope Checklist
Liquid-filled transformer pressure devices need separate RFQ entries for relief, pressure indication and rapid-pressure sensing. Confirm device variants, mou...
Read the guideCompare quotations
Put the proposals
on the same basis.
A lower price is only comparable when the proposed equipment and supply scope match. Record differences and resolve them before ordering.
Equipment
Compare capacity, voltages, phase, frequency, impedance, cooling and installation requirements against the same specification.
Documents and testing
Identify the proposed model, drawings, required test reports and any mandatory approvals. Check what is included and excluded.
Commercial scope
Compare quantity, delivery term and named place, packaging, transport, lead time, payment and warranty in writing.
Project documents
The right document. For the right model.
Tell us which documents your project needs. Availability and applicable scope are confirmed for the proposed model and configuration.
Outline and connection drawings
State the installation, cable-entry and clearance requirements you need to check.
Request for your projectTest and approval documents
Name the required tests, standard or approval, and the model or configuration concerned.
Request for your projectRequest documents for your proposed configuration
Include the model or product type, capacity, voltages, frequency and destination. Ask for the report number, date and test scope so you can check that the documents match the proposed configuration. An individual report does not establish certification for every model or destination.
When reviewing a document, match the legal entity, model, rating, applicable scope and issue date to your proposed equipment.
Read the certificate-scope guideOpen the document centreYour project / next step
Good decisions start with clear requirements.
Send the details you have. We can start the conversation while the remaining requirements are being confirmed.
Discuss your project