Transformer Secondary Current Calculator
Find the exact output current of your transformer in seconds. This transformer secondary current calculator helps you calculate load current quickly and accurately. Use it to design, size, and verify your electrical systems with confidence.
Secondary Current Calculator
How to Use Transformer Secondary Current Calculator
Follow these simple steps to use the transformer secondary current calculator:
- Step 1: Enter Transformer Power Rating (kVA): Input the transformer rating in kilovolt-amperes (kVA).
- Step 2: Enter Secondary Voltage (V): Provide the secondary voltage value in volts (V).
- Step 3: Select Phase Type: Choose between Single-phase or Three-phase.
- Step 4: Click Calculate: The calculator will instantly display the secondary current in amperes (A).
- Step 5: Review the Result: Use the result for cable sizing, protection device selection, and load calculations.
How to Calculate Transformer Secondary Current
You can manually calculate transformer secondary current using standard formulas.
Formula
For Single-Phase Transformer:
For Three-Phase Transformer:
Step-by-Step Example
Example:
Transformer Rating = 100 kVA
Secondary Voltage = 400 V
Type =
Three-phase
Step 1: Write the formula
I = (kVA × 1000) / (√3 × V)
Step 2: Substitute values
I = (100 × 1000) / (1.732 × 400)
Step 3: Solve
I = 100000 / 692.8
I ≈ 144.3 A
Final Answer:
Transformer secondary current = 144.3 Amps
Transformer Secondary Current Conversion Chart
| kVA Rating | Voltage (V) | Phase | Secondary Current (A) |
|---|---|---|---|
| 25 kVA | 230 V | Single | 108.7 A |
| 50 kVA | 230 V | Single | 217.4 A |
| 75 kVA | 400 V | Three | 108.2 A |
| 100 kVA | 400 V | Three | 144.3 A |
| 150 kVA | 400 V | Three | 216.5 A |
| 200 kVA | 415 V | Three | 278.6 A |
| 250 kVA | 415 V | Three | 348.3 A |
| 500 kVA | 415 V | Three | 696.6 A |
Note: Values are approximate and based on standard calculations.
FAQs About Transformer Secondary Current Calculator
A transformer secondary current calculator helps you determine the output current of a transformer based on kVA and voltage.
It helps you select correct cable sizes, circuit breakers, and protection devices.
Primary current flows into the transformer. Secondary current flows out to the load.
No. Use the single-phase formula for single-phase transformers and the three-phase formula for three-phase transformers.
In basic calculations, kVA already includes power factor. So, you do not need it separately.
Transformer current is measured in amperes (A).
Yes. It provides accurate results for design and estimation purposes when correct inputs are used.