Comprehensive technical data for 300 kVA dry transformers including dimensions, weight, full load amps, installation tips, and sizing guidance
Quick Specifications
| Rated Power: | 300 kVA | Phase: | Three-Phase |
| Primary Voltage: | 480V | Secondary Voltage: | 208Y/120V |
| Weight: | 1300 lbs (590 kg) | Efficiency: | 99.0% |
| Dimensions (H×W×D): | 58″ × 32″ × 28″ (1473 × 813 × 711 mm) | ||
A 300 kVA transformer is commonly used in Major industrial facilities. This guide provides complete specifications to help engineers and purchasers select and install 300 kVA transformers correctly.
300 kVA Transformer Dimensions
| Dimension | Metric (mm) | Imperial (inches) |
|---|---|---|
| Height (H) | 1473 mm | 58″ |
| Width (W) | 813 mm | 32″ |
| Depth (D) | 711 mm | 28″ |
300 kVA Transformer Weight
| Weight Type | Pounds (lbs) | Kilograms (kg) |
|---|---|---|
| Dry-Type Transformer | 1300 lbs | 590 kg |
| Oil-Filled Equivalent* | ~1950 lbs | ~885 kg |
| Shipping Weight (Approx.) | ~1430 lbs | ~649 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 300 kVA three-phase transformer:
| Voltage | Full Load Amps | Suggested Wire Size |
|---|---|---|
| 120V | 1443.4 A | 750 MCM+ |
| 208V | 832.7 A | 750 MCM+ |
| 240V | 721.7 A | 750 MCM+ |
| 277V | 625.3 A | 750 MCM+ |
| 480V | 360.9 A | 500 MCM |
| 600V | 288.7 A | 400 MCM |
Three-Phase:
Amps = (kVA × 1000) ÷ (Voltage × 1.732)Example at 480V:
360.9 A = (300 × 1000) ÷ (480 × 1.732)Electrical Specifications
| Parameter | Value | Notes |
|---|---|---|
| Rated kVA | 300 kVA | At rated voltage and frequency |
| Frequency | 60 Hz | 50 Hz available on request |
| No-Load Loss | 420 W | Core/iron losses (typical) |
| Load Loss | 1900 W | Copper losses at 100% load |
| Total Losses | 2320 W | At 100% load |
| Impedance | 5.5% | ±7.5% tolerance per IEEE |
| Efficiency | 99.0% | At 100% load |
| Sound Level | ~46 dB | Per NEMA ST-20 (estimated) |
- Large transformers like this 300 kVA unit generate significant heat. Verify room ventilation capacity before installation.
- Floor loading of 1300 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 300 kVA Three-Phase Transformer the Right Choice?
A 300 kVA three-phase transformer is designed for:
- Medium industrial facilities and machine shops
- Multi-story commercial buildings
- Large HVAC central plant systems
- Printing and packaging operations
- Food processing facilities
Capacity Planning:
At 300 kVA, you can support approximately 179 HP of combined motor load at 80% efficiency and 0.85 power factor.
Typical Load Examples for 300 kVA
Example load distribution for a 300 kVA installation:
| Load Type | Estimated Demand |
|---|---|
| Process motors | 105 kVA |
| HVAC chillers | 75 kVA |
| Lighting systems | 36 kVA |
| Welding equipment | 45 kVA |
| Support systems | 39 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 |
|---|---|
| 225 kVA Three-Phase | 225 kVA Specifications → |
| 300 kVA Three-Phase | Current Page |
| 500 kVA Three-Phase | 500 kVA Specifications → |
Frequently Asked Questions
What are the dimensions of a 300 kVA transformer?
A typical 300 kVA dry three-phase transformer measures approximately 58″ H × 32″ W × 28″ D (1473 × 813 × 711 mm). Dimensions vary by manufacturer.
How much does a 300 kVA transformer weigh?
A 300 kVA dry transformer typically weighs around 1300 lbs (590 kg). Oil-filled transformers of the same rating weigh approximately 1950 lbs.
What is the full load amperage of a 300 kVA transformer at 480V?
At 480V, a 300 kVA three-phase transformer has a full load current of 360.9 amps.
What loads can a 300 kVA transformer handle?
A 300 kVA transformer can supply up to 300 kVA of apparent power. For typical loads with 0.85 power factor, this equals approximately 255.0 kW of real power.
Related Resources
- 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