15 kVA Three-Phase Transformer: Complete Specifications & Dimensions

Comprehensive technical data for 15 kVA dry transformers including dimensions, weight, full load amps, installation tips, and sizing guidance

Quick Specifications

Rated Power:15 kVAPhase:Three-Phase
Primary Voltage:480VSecondary Voltage:208Y/120V
Weight:190 lbs (86 kg)Efficiency:98.0%
Dimensions (H×W×D):30″ × 18″ × 14″ (762 × 457 × 356 mm)

A 15 kVA transformer is commonly used in Small three-phase loads. This guide provides complete specifications to help engineers and purchasers select and install 15 kVA transformers correctly.

⚠️ Important: Specifications shown are typical values for reference. Actual dimensions and weights vary by manufacturer. Always verify with manufacturer datasheet before ordering.

15 kVA Transformer Dimensions

15-0-kva-three-phase-transformer-dimensions
15 kVA Three-Phase Transformer Dimensions (Typical)
DimensionMetric (mm)Imperial (inches)
Height (H)762 mm30″
Width (W)457 mm18″
Depth (D)356 mm14″
🔧 Installation Note: At 190 lbs, this 15 kVA transformer requires proper rigging equipment for installation. Use a pallet jack or forklift for safe positioning. Ensure floor can support the load plus any additional connected equipment weight.

15 kVA Transformer Weight

Weight TypePounds (lbs)Kilograms (kg)
Dry-Type Transformer190 lbs86 kg
Oil-Filled Equivalent*~285 lbs~129 kg
Shipping Weight (Approx.)~209 lbs~94 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 15 kVA three-phase transformer:

VoltageFull Load AmpsSuggested Wire Size
120V72.2 A#3 AWG
208V41.6 A#6 AWG
240V36.1 A#8 AWG
277V31.3 A#8 AWG
480V18.0 A#12 AWG
600V14.4 A#14 AWG
Formula Used:
Three-Phase: Amps = (kVA × 1000) ÷ (Voltage × 1.732)
Example at 480V: 18.0 A = (15 × 1000) ÷ (480 × 1.732)

Electrical Specifications

ParameterValueNotes
Rated kVA15 kVAAt rated voltage and frequency
Frequency60 Hz50 Hz available on request
No-Load Loss70 WCore/iron losses (typical)
Load Loss200 WCopper losses at 100% load
Total Losses270 WAt 100% load
Impedance3.5%±7.5% tolerance per IEEE
Efficiency98.0%At 100% load
Sound Level~40 dBPer NEMA ST-20 (estimated)

⚠️ Important Considerations for 15 kVA Transformers:

  • At 15 kVA, ensure adequate ventilation clearance (minimum 3″ sides, 6″ top) for proper cooling.

When is a 15 kVA Three-Phase Transformer the Right Choice?

A 15 kVA three-phase transformer is ideal for:

  • Small manufacturing facilities with 3-phase equipment
  • Commercial kitchens with three-phase ovens
  • HVAC systems with 3-phase compressors up to 7 HP
  • Elevator and escalator power supply
  • Multi-tenant building common areas

Three-Phase Advantage: Compared to single-phase, this transformer delivers 13.0 kW at unity power factor with balanced loading across all phases.

Typical Load Examples for 15 kVA

Example load distribution for a 15 kVA installation:

Load TypeEstimated Demand
Three-phase HVAC compressor6 kVA
3-phase motors (combined)4 kVA
Lighting transformer2 kVA
Receptacle loads2 kVA

Note: Actual loads vary. Always perform a detailed load calculation for your specific application.


Related Transformer Sizes

Compare with adjacent kVA ratings:

kVA RatingLink
15 kVA Three-Phase15 kVA Specifications →
15 kVA Three-PhaseCurrent Page
30 kVA Three-Phase30 kVA Specifications →

Frequently Asked Questions

What are the dimensions of a 15 kVA transformer?

A typical 15 kVA dry three-phase transformer measures approximately 30″ H × 18″ W × 14″ D (762 × 457 × 356 mm). Dimensions vary by manufacturer.

How much does a 15 kVA transformer weigh?

A 15 kVA dry transformer typically weighs around 190 lbs (86 kg). Oil-filled transformers of the same rating weigh approximately 285 lbs.

What is the full load amperage of a 15 kVA transformer at 480V?

At 480V, a 15 kVA three-phase transformer has a full load current of 18.0 amps.

What loads can a 15 kVA transformer handle?

A 15 kVA transformer can supply up to 15 kVA of apparent power. For typical loads with 0.85 power factor, this equals approximately 12.8 kW of real power.


Related Resources

📊 Complete Reference Charts:

Related Articles


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

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