How to Write a 1250 kVA Cast Resin Transformer RFQ: Complete Template and Procurement Recommendations

For EPC contractors, consulting engineers, and industrial procurement managers, a well-structured Request for Quotation (RFQ) is one of the most effective tools for reducing procurement risks, shortening quotation cycles, and identifying qualified transformer manufacturers at an early stage.

This guide provides a complete RFQ framework for a 1250 kVA Cast Resin Dry-Type Transformer, including IEC 60076-11 technical requirements, supplier qualification criteria, pricing references, and contract considerations. It is suitable for power distribution projects in industrial plants, commercial buildings, data centers, infrastructure developments, transportation systems, and renewable energy facilities.

Why Choose a 1250 kVA Cast Resin Transformer?

The 1250 kVA rating is one of the most widely used transformer capacities in medium-voltage distribution systems. It offers an ideal balance between load capacity, installation flexibility, efficiency, and total ownership cost.

Typical applications include manufacturing plants, commercial complexes, hospitals, airports, metro stations, data centers, high-rise buildings, mining operations, and offshore platforms.

Compared with oil-immersed transformers, cast resin transformers provide several important advantages. Because they operate without insulating oil, there is no risk of oil leakage, environmental contamination, or fire caused by combustible insulating liquids. This makes them especially suitable for indoor installations where safety requirements are stringent.

Vacuum-cast epoxy resin insulation also provides excellent dielectric strength, moisture resistance, and short-term overload capability. Combined with their maintenance-free design, cast resin transformers can significantly reduce lifecycle operating costs while improving system reliability.

Typical Technical Baseline for a 1250 kVA Cast Resin Transformer

Parameter	Typical Value
Rated Power	1250 kVA
Primary Voltage	6.3 kV / 10 kV / 11 kV
Secondary Voltage	400 V / 433 V / 690 V
Vector Group	Dyn11
Insulation Class	Class F (Class B Temperature Rise)
Cooling Method	AN Natural Air Cooling
Loss Category	B0 / C0 According to IEC 60076-11
Protection Degree	IP20 / IP23 / IP34

Preparation Before Drafting the RFQ

Define Installation Conditions

Transformer ratings are generally based on standard operating conditions, including an altitude below 1000 meters, maximum ambient temperature of 40°C, daily average temperature below 30°C, and annual average temperature below 20°C.

If the project site exceeds these limits, actual environmental conditions must be specified in the RFQ. Manufacturers may need to provide derating calculations or alternative cooling solutions. At elevations around 2000 meters, transformer output capacity may be reduced by approximately 10% to 15% unless special design measures are implemented.

Select the Applicable Standard

The selected standard directly affects testing requirements, documentation, and acceptance procedures.

IEC 60076-11 is the preferred standard for Europe, the Middle East, Africa, Southeast Asia, and most international projects. GB/T 1094.11 is widely used within China and remains technically aligned with IEC requirements. IEEE C57 standards are typically specified for North American projects.

The RFQ should clearly identify the governing standard and indicate whether equivalent standards are acceptable.

Analyze Load Characteristics

Projects involving UPS systems, variable frequency drives (VFDs), data centers, battery energy storage systems, or rectifier loads should include harmonic information in the RFQ.

Where significant harmonic distortion exists, buyers should specify the required K-factor rating and request confirmation of harmonic withstand capability. For many industrial applications, K13 or K20 transformer designs are commonly selected.

Procurement Tip: Before issuing a formal RFQ, conduct a preliminary Request for Information (RFI) with several manufacturers. Early technical discussions often reduce quotation lead times from four to six weeks down to two or three weeks.

1250 kVA Cast Resin Transformer RFQ Template

Project Information

Project Name: [Insert Project Name]

RFQ Number: [Insert RFQ Reference]

Quotation Deadline: [Insert Date]

Section 1: Basic Technical Requirements

Rated Capacity: 1250 kVA

Frequency: 50 Hz / 60 Hz

Phase: Three-Phase

Primary Voltage: [Specify Voltage and Tapping Range]

Secondary Voltage: [Specify Voltage]

Vector Group: Dyn11

Insulation Class: Class F with Class B Temperature Rise

Cooling Method: AN Natural Air Cooling

Section 2: Efficiency and Loss Requirements

No-Load Loss (P0): ≤ [Specify Value]

Load Loss at 75°C (Pk): ≤ [Specify Value]

No-Load Current: ≤ 1.0%

Short Circuit Impedance: 6% ±10%

Section 3: Insulation and Testing Requirements

Lightning Impulse Level: 75 kV for 10 kV systems

Power Frequency Withstand Voltage: 35 kV / 3 kV for 60 seconds

Partial Discharge Level: ≤10 pC at 1.1 × U0

Applicable Standard: IEC 60076-11 / Equivalent Approved Standard

Section 4: Installation Requirements

Protection Degree: IP20 / IP23 / IP34

Installation Altitude: [Specify]

Maximum Ambient Temperature: [Specify]

Mounting Arrangement: Fixed Base / Wheels / Lifting Lugs

Enclosure Color: RAL7035 or Project Requirement

Section 5: Optional Accessories

Digital Temperature Controller

Forced Air Cooling System (ANAF)

Neutral Copper Busbar

Grounding Busbar

Anti-Vibration Pads

Section 6: Commercial Requirements

Trade Term: FOB [Port]

Quantity Required: [Specify]

Delivery Time: [Specify]

Warranty Period: Minimum 24 Months

Required Documentation: Type Test Reports, Technical Datasheets, Outline Drawings, Nameplate Drawings, Installation Manuals

Understanding Critical Technical Parameters

Loss Classification

IEC 60076-11 categorizes transformer losses into various efficiency classes. Selecting lower-loss designs can substantially reduce electricity costs over the transformer's operational life.

C0-level transformers generally achieve significantly lower no-load losses compared with conventional A0-rated units. Over a 20-year operating period, the energy savings often justify the higher initial investment.

For extreme climate environments, climate classifications such as C1 and C2 should also be specified. C2 designs are suitable for ambient temperatures ranging from -25°C to +40°C.

Insulation Class and Temperature Rise

A common industry practice is to use Class F insulation while limiting temperature rise to Class B levels. This approach creates additional thermal margin and improves insulation life expectancy.

To avoid ambiguity, procurement documents should require manufacturers to clearly state both insulation class and guaranteed temperature rise values.

Short-Circuit Impedance

The standard impedance for a 1250 kVA transformer is typically 6%. This provides a practical balance between fault current limitation and voltage regulation performance.

Projects requiring enhanced voltage stability may specify impedance levels of 6.5% or 7%. Lower impedance values may reduce manufacturing costs but can increase fault current levels.

Important: Require all loss values to be guaranteed at full rated load and referenced to the specified winding temperature, typically 75°C.

1250 kVA Cast Resin Transformer FOB Price Reference

The following budgetary price ranges represent typical FOB quotations from major Chinese export ports such as Shanghai, Ningbo, and Tianjin. Actual prices vary according to technical specifications, certification requirements, raw material costs, and order quantities.

Configuration	Voltage Class	Loss Class	Protection	FOB Price Range (USD)
Basic Configuration	10 kV / 0.4 kV	A0	IP20	$16,000 – $20,000
Standard Configuration	10 kV / 0.4 kV	B0	IP23	$20,000 – $26,000
High-Efficiency Configuration	11 kV / 0.433 kV	C0	IP23	$26,000 – $33,000
Protected Enclosure Type	11 kV / 0.433 kV	C0	IP34	$30,000 – $38,000
35 kV Special Design	35 kV / 0.4 kV	B0	IP23	$38,000 – $50,000

The main cost drivers include copper prices, electrical steel grade, epoxy resin system quality, protection enclosure requirements, cooling accessories, and production lead time.

Supplier Qualification Checklist

Before selecting a supplier, procurement teams should verify quality systems, testing capabilities, export experience, and after-sales support.

The manufacturer should maintain a valid ISO 9001 quality management certification and be capable of providing complete type test reports for transformers of similar ratings.

Type test documentation should include temperature rise testing, lightning impulse testing, partial discharge testing, and short-circuit withstand verification.

For European projects, suppliers should be able to provide CE compliance documentation and declarations of conformity where applicable.

For GCC countries and Middle Eastern projects, buyers should confirm compliance with local certification requirements such as SASO or other regional standards.

The supplier should also demonstrate international shipping experience, acceptance of third-party inspection services, and the ability to provide references from comparable projects.

RFQ Distribution and Bid Evaluation Strategy

For effective market competition, it is generally recommended to invite quotations from four to six qualified manufacturers. Too few suppliers may limit price competitiveness, while too many can complicate technical evaluation.

All quotations should be reviewed using a standardized Technical Deviation Sheet. This allows buyers to identify specification differences and quantify their financial impact before making a final selection.

Rather than evaluating bids solely on purchase price, buyers should consider Total Ownership Cost (TOC), including energy losses, maintenance expenses, reliability, and service support over the transformer's expected operating life.

Even a small reduction in no-load losses can generate significant long-term savings. In many industrial applications, lifecycle energy costs often exceed the original transformer purchase price.

Critical Contract Attachment Requirements

Once a supplier is selected, the final technical specification should become an integral part of the purchase contract.

Key contractual provisions should include guaranteed loss values, penalties for non-compliance, guaranteed dimensions and weights, factory acceptance testing requirements, packaging standards, transportation protection measures, spare parts obligations, warranty terms, and complete technical documentation deliverables.

Best practice is to require suppliers to submit a detailed Technical Deviation Sheet together with their quotation. Manufacturers unwilling to clearly disclose deviations often create increased contractual and operational risks during project execution.

A professionally prepared RFQ is one of the most effective tools for ensuring successful procurement of a 1250 kVA cast resin transformer. By clearly defining technical requirements, environmental conditions, testing standards, commercial terms, and supplier qualification criteria, buyers can significantly reduce project risk while obtaining more accurate and competitive quotations.

For international EPC projects, combining a detailed RFQ with lifecycle cost analysis and supplier qualification reviews provides the strongest foundation for selecting a reliable transformer partner and achieving long-term operational performance.