Comprehensive technical data for 7.5 kVA dry transformers including dimensions, weight, full load amps, installation tips, and sizing guidance
Quick Specifications
| Rated Power: | 7.5 kVA | Phase: | Single-Phase |
| Primary Voltage: | 480V | Secondary Voltage: | 120/240V |
| Weight: | 100 lbs (45 kg) | Efficiency: | 97.9% |
| Dimensions (H×W×D): | 24″ × 16″ × 11″ (610 × 406 × 279 mm) | ||
A 7.5 kVA transformer is commonly used in Small commercial loads, residential backup. This guide provides complete specifications to help engineers and purchasers select and install 7.5 kVA transformers correctly.
7.5 kVA Transformer Dimensions
| Dimension | Metric (mm) | Imperial (inches) |
|---|---|---|
| Height (H) | 610 mm | 24″ |
| Width (W) | 406 mm | 16″ |
| Depth (D) | 279 mm | 11″ |
7.5 kVA Transformer Weight
| Weight Type | Pounds (lbs) | Kilograms (kg) |
|---|---|---|
| Dry-Type Transformer | 100 lbs | 45 kg |
| Oil-Filled Equivalent* | ~150 lbs | ~67 kg |
| Shipping Weight (Approx.) | ~110 lbs | ~49 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 7.5 kVA single-phase transformer:
| Voltage | Full Load Amps | Suggested Wire Size |
|---|---|---|
| 120V | 62.5 A | #4 AWG |
| 208V | 36.1 A | #8 AWG |
| 240V | 31.2 A | #8 AWG |
| 277V | 27.1 A | #10 AWG |
| 480V | 15.6 A | #12 AWG |
| 600V | 12.5 A | #14 AWG |
Single-Phase:
Amps = (kVA × 1000) ÷ VoltageExample at 480V:
15.6 A = (7.5 × 1000) ÷ 480Electrical Specifications
| Parameter | Value | Notes |
|---|---|---|
| Rated kVA | 7.5 kVA | At rated voltage and frequency |
| Frequency | 60 Hz | 50 Hz available on request |
| No-Load Loss | 40 W | Core/iron losses (typical) |
| Load Loss | 110 W | Copper losses at 100% load |
| Total Losses | 150 W | At 100% load |
| Impedance | 3.0% | ±7.5% tolerance per IEEE |
| Efficiency | 97.9% | At 100% load |
| Sound Level | ~40 dB | Per NEMA ST-20 (estimated) |
⚠️ Important Considerations for 7.5 kVA Transformers:
- Small transformers like this 7.5 kVA unit are sensitive to overloading. Limit sustained load to 80% of rated capacity.
When is a 7.5 kVA Transformer the Right Choice?
A 7.5 kVA single-phase transformer is ideal for:
- Small commercial spaces under 1,500 sq ft
- Individual HVAC units up to 5 HP
- Lighting loads for parking areas or small warehouses
- Control power for industrial equipment
- Residential service entrance upgrades
Consider upgrading to 10 kVA if:
- You anticipate load growth within 5 years
- Multiple motor loads may start simultaneously
- Non-linear loads (VFDs, computers) exceed 30% of total
Typical Load Examples for 7.5 kVA
Example load distribution for a 7.5 kVA installation:
| Load Type | Estimated Demand |
|---|---|
| Small air conditioning unit | 3 kVA |
| Office lighting (LED) | 1 kVA |
| Desktop computers (5-10) | 1 kVA |
| Small pumps/motors | 1 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 |
|---|---|
| 5 kVA Single-Phase | 5 kVA Specifications → |
| 7.5 kVA Single-Phase | Current Page |
| 10 kVA Single-Phase | 10 kVA Specifications → |
Frequently Asked Questions
What are the dimensions of a 7.5 kVA transformer?
A typical 7.5 kVA dry single-phase transformer measures approximately 24″ H × 16″ W × 11″ D (610 × 406 × 279 mm). Dimensions vary by manufacturer.
How much does a 7.5 kVA transformer weigh?
A 7.5 kVA dry transformer typically weighs around 100 lbs (45 kg). Oil-filled transformers of the same rating weigh approximately 150 lbs.
What is the full load amperage of a 7.5 kVA transformer at 480V?
At 480V, a 7.5 kVA single-phase transformer has a full load current of 15.6 amps.
What loads can a 7.5 kVA transformer handle?
A 7.5 kVA transformer can supply up to 7.5 kVA of apparent power. For typical loads with 0.85 power factor, this equals approximately 6.4 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