1. What is 3 Phase Transformer Calculation?

The 3-phase transformer calculator determines the required kVA rating of a transformer based on the power in watts and the power factor. This is essential for proper electrical system design and equipment selection.

2. How Does the Calculator Work?

The calculator uses the 3-phase transformer formula:

Where:

• \( kVA \) — Transformer rating in kilovolt-amperes
• \( P \) — Power in watts (W)
• \( \cos \phi \) — Power factor (dimensionless, between 0 and 1)

Explanation: The formula converts real power (watts) to apparent power (kVA) accounting for the power factor, which represents the phase difference between voltage and current.

3. Importance of Transformer Rating

Details: Proper transformer sizing is crucial for efficient power distribution, preventing overload conditions, and ensuring reliable operation of electrical systems.

4. Using the Calculator

Tips: Enter the power in watts and the power factor (typically 0.8-0.95 for industrial loads). The power factor must be between 0.01 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical power factor value?
A: Industrial loads typically have power factors between 0.8-0.95. Residential loads often range from 0.95-1.0.

Q2: Why convert watts to kVA?
A: Transformers are rated in kVA (apparent power) because they must supply both the real power (watts) and reactive power (VARs) required by the load.

Q3: What happens if I undersize a transformer?
A: An undersized transformer may overheat, have reduced lifespan, or fail to properly supply the connected loads.

Q4: Does this calculation include efficiency losses?
A: No, this is the theoretical calculation. In practice, you should add 10-20% capacity to account for losses and future expansion.

Q5: Can I use this for single-phase transformers?
A: The basic formula is similar, but single-phase calculations use different voltage and current relationships.