High-Efficiency Cast Resin Dry-Type Transformers for Data Centers

Premium K-Factor Rated | 1000kVA – 3150kVA | Class H Insulation | IEEE / IEC Compliant

Engineered specifically for mission-critical data center power chains, our K-factor rated cast resin dry-type transformers deliver superior harmonic handling, low losses, and high thermal stability. Designed to feed UPS systems, PDU inputs, and non-linear IT loads, these transformers help reduce PUE while ensuring 24/7/365 reliability.

This landing page covers the data center optimized range (1000kVA – 3150kVA) . For other ratings, refer to our standard SCB10 series:

• SCB10 11kV Class (100kVA – 4000kVA) → View Product Page
• SCB10 33kV Class (50kVA – 2500kVA) → View Product Page

Why Data Centers Need K-Factor Rated Transformers

Modern data centers contain non-linear loads: UPS rectifiers, switch-mode power supplies, servers, and storage devices. These loads generate harmonic currents (especially 3rd, 5th, 7th, 9th orders) that cause:

A K-factor rated transformer is designed with:

• Reduced flux density to accommodate harmonic flux
• Larger neutral bushing (200% of phase rating for K-13)
• Double-sized neutral conductor inside windings
• Enhanced winding eddy loss mitigation (transposed conductors, foil windings)

Our K-4, K-7, K-13, and K-20 rated transformers directly address these issues per IEEE C57.110.

Technical Overview – Data Center Optimized Range

K-Factor Selection Guide for Data Centers

Engineering recommendation: For new data centers without a harmonic study, specify K-13 as a conservative choice. For retrofit or upgrade projects, perform a harmonic survey first.

Key Engineering Features for Data Centers

1. Class H Insulation (180°C)

• 20°C higher thermal margin than standard Class F (used in SCB10 series)
• Allows for emergency overload without accelerated aging
• Ideal for N+1 redundant configurations where a single transformer may carry 100% load during maintenance

2. Low Losses for PUE Reduction

• No-load losses: ≤ 1800W for 2000kVA unit (optimized core)
• Load losses at 75°C: ≤ 17000W for 2000kVA unit (copper windings)
• Total losses 10-15% lower than standard dry types → reduces cooling load in electrical room

3. Superior Harmonic Handling

• Double-sized neutral bushing (standard for all K-factor units)
• Full-height copper foil windings on LV side – minimizes eddy losses
• Interleaved disc windings on HV side – reduces harmonic flux

4. Low Partial Discharge

• Vacuum cast resin process ensures PD < 10pC at 1.73 × rated voltage
• Critical for long-term reliability in 24/7 operation

5. Low Noise

• Optimized core step-lap joints → ≤ 62 dB(A) at 1m (for 2000kVA)
• Optional enclosure with acoustic damping available

Compliance & Testing

Each data center transformer is factory tested per IEEE C57.12.91 and IEC 60076-11. The Factory Acceptance Test (FAT) includes:

• Winding resistance measurement (all taps)
• Voltage ratio and vector group verification
• No-load loss and excitation current
• Load loss and impedance voltage (corrected to 120°C for Class H)
• Induced overvoltage test (ACS) – 30kV for 11kV class
• Separate source AC withstand – 10kV for LV side
• Partial discharge measurement – ≤10pC
• K-factor verification (per IEEE C57.110 – optional, can be witnessed)

Third-party inspection: SGS, TÜV, Bureau Veritas, or Intertek available upon request.

Cooling & Overload Capability

Class H insulation allows:

• 20% overload for 1 hour (emergency)
• 10% continuous overload at 40°C ambient

Procurement Guide for Data Center Applications

Step 1 – Select kVA Based on IT Load

Step 2 – Choose K-Factor

If you do not have a harmonic study, provide:

• UPS type (6-pulse, 12-pulse, IGBT)
• Presence of active filters
• Percentage of non-linear load

We will recommend the optimal K-factor.

Step 3 – Specify Voltage and Tapping

• Primary voltage: Match utility or generator output (typical: 11kV, 10kV, 6kV)
• Secondary voltage: Match UPS input (typical: 480V, 415V, 400V)
• Tapping range: ±2×2.5% or ±5% on HV side (for voltage regulation)

Step 4 – Request Loss Capitalization Calculation

For data centers, transformer losses directly impact PUE. We provide a loss capitalization table based on:

• Local electricity cost ($/kWh)
• Transformer load factor (typical: 60-80% for N config, 40-60% for N+1)
• Cooling cost multiplier (1.2 – 1.5 due to room HVAC)

Typical Data Center Configurations

Configuration A: 2N (Fully Redundant)

• Two independent transformers, each sized for 100% of load
• Each transformer loaded at 40-50% in normal operation
• Select K-4 or K-7 (lower harmonics due to lower loading)

Configuration B: N+1 (Block Redundant)

• Three transformers, two active, one standby
• Active units loaded at 60-70%
• Select K-7 or K-13

Configuration C: N (No Redundancy)

• Single transformer feeding whole UPS chain
• Loaded at 70-85%
• Select K-13 or K-20

Our dry-type transformers are specifically optimized for hyperscale and edge data centers. Unlike standard industrial units, these are engineered with a high K-factor rating (up to K-13) to mitigate the thermal effects of non-linear loads and harmonics generated by switching power supplies.

[Asia Power] – Transformer Engineering Department
K-Factor Rated Dry-Type Transformers for Mission-Critical Data Centers
IEEE C57.110 • IEC 60076 • Class H Insulation • Factory Tested