Comprehensive technical data for 250 kVA dry transformers including dimensions, weight, full load amps, installation tips, and sizing guidance
Quick Specifications
| Rated Power: | 250 kVA | Phase: | Single-Phase |
| Primary Voltage: | 480V | Secondary Voltage: | 120/240V |
| Weight: | 1200 lbs (544 kg) | Efficiency: | 99.1% |
| Dimensions (H×W×D): | 60″ × 34″ × 28″ (1524 × 864 × 711 mm) | ||
A 250 kVA transformer is commonly used in Major industrial, grid substations. This guide provides complete specifications to help engineers and purchasers select and install 250 kVA transformers correctly.
250 kVA Transformer Dimensions
| Dimension | Metric (mm) | Imperial (inches) |
|---|---|---|
| Height (H) | 1524 mm | 60″ |
| Width (W) | 864 mm | 34″ |
| Depth (D) | 711 mm | 28″ |
250 kVA Transformer Weight
| Weight Type | Pounds (lbs) | Kilograms (kg) |
|---|---|---|
| Dry-Type Transformer | 1200 lbs | 544 kg |
| Oil-Filled Equivalent* | ~1800 lbs | ~816 kg |
| Shipping Weight (Approx.) | ~1320 lbs | ~598 kg |
*Oil-filled transformer weight is estimated at approximately 1.5× dry-type weight.
Full Load Amps at Various Voltages
The following table shows calculated full load amperage for a 250 kVA single-phase transformer:
| Voltage | Full Load Amps | Suggested Wire Size |
|---|---|---|
| 120V | 2083.3 A | 750 MCM+ |
| 208V | 1201.9 A | 750 MCM+ |
| 240V | 1041.7 A | 750 MCM+ |
| 277V | 902.5 A | 750 MCM+ |
| 480V | 520.8 A | 750 MCM+ |
| 600V | 416.7 A | 750 MCM+ |
Single-Phase:
Amps = (kVA × 1000) ÷ VoltageExample at 480V:
520.8 A = (250 × 1000) ÷ 480Electrical Specifications
| Parameter | Value | Notes |
|---|---|---|
| Rated kVA | 250 kVA | At rated voltage and frequency |
| Frequency | 60 Hz | 50 Hz available on request |
| No-Load Loss | 320 W | Core/iron losses (typical) |
| Load Loss | 1500 W | Copper losses at 100% load |
| Total Losses | 1820 W | At 100% load |
| Impedance | 5.0% | ±7.5% tolerance per IEEE |
| Efficiency | 99.1% | At 100% load |
| Sound Level | ~45 dB | Per NEMA ST-20 (estimated) |
⚠️ Important Considerations for 250 kVA Transformers:
- Large transformers like this 250 kVA unit generate significant heat. Verify room ventilation capacity before installation.
- Floor loading of 1200 lbs requires structural verification. Contact a structural engineer for slab-on-grade installations.
- Impedance matching is critical when paralleling transformers. Consult a power systems engineer.
When is a 250 kVA Transformer the Right Choice?
A 250 kVA single-phase transformer is designed for substantial loads:
- Large commercial facilities (10,000+ sq ft)
- Industrial workshops with heavy machinery
- Data center backup power systems
- Large agricultural operations
- Mining and extraction equipment
Engineering Considerations:
- Voltage drop calculations become critical at this size
- Short circuit current analysis required
- Consider redundant transformer configuration for critical loads
- Coordinate overcurrent protection with utility requirements
Typical Load Examples for 250 kVA
Example load distribution for a 250 kVA installation:
| Load Type | Estimated Demand |
|---|---|
| Industrial HVAC | 62 kVA |
| Production equipment | 87 kVA |
| Facility lighting | 37 kVA |
| Compressed air system | 37 kVA |
| Office/admin loads | 25 kVA |
Note: Actual loads vary. Always perform a detailed load calculation for your specific application.
Related Transformer Sizes
Compare with adjacent kVA ratings:
| kVA Rating | Link |
|---|---|
| 167 kVA Single-Phase | 167 kVA Specifications → |
| 250 kVA Single-Phase | Current Page |
| 250 kVA Single-Phase | 250 kVA Specifications → |
Frequently Asked Questions
What are the dimensions of a 250 kVA transformer?
A typical 250 kVA dry single-phase transformer measures approximately 60″ H × 34″ W × 28″ D (1524 × 864 × 711 mm). Dimensions vary by manufacturer.
How much does a 250 kVA transformer weigh?
A 250 kVA dry transformer typically weighs around 1200 lbs (544 kg). Oil-filled transformers of the same rating weigh approximately 1800 lbs.
What is the full load amperage of a 250 kVA transformer at 480V?
At 480V, a 250 kVA single-phase transformer has a full load current of 520.8 amps.
What loads can a 250 kVA transformer handle?
A 250 kVA transformer can supply up to 250 kVA of apparent power. For typical loads with 0.85 power factor, this equals approximately 212.5 kW of real power.
Related Resources
📊 Complete Reference Charts:
- Transformer Sizing Chart – Compare all kVA ratings with dimensions & weights
- Transformer Full Load Amps Chart – FLA reference for all voltages
Related Articles
- Three Phase Transformer: Complete Guide
- Transformer Testing: Complete Guide
- Transformer Protection: Complete Guide
Standards & References
- IEEE C57.12.01 – General Requirements for Dry-Type Transformers
- IEEE C57.12.91 – Test Code for Dry-Type Transformers
- NEMA TP-1 – Guide for Determining Energy Efficiency
- DOE 10 CFR 431 – Energy Conservation Standards
Disclaimer: Specifications shown are typical reference values compiled from multiple industry sources. Actual specifications vary significantly by manufacturer, model, enclosure type, and configuration. Always consult manufacturer datasheets for exact specifications before ordering or installation. Data accuracy verified using standard electrical engineering formulas. Last updated: January 2026