Switchgear kW to Volts Calculator
Convert switchgear real power (kW) to system voltage (Volts) for single-phase and three-phase electrical systems
Single-Phase: V = (kW × 1000) / (I × PF)
|
Three-Phase: V = (kW × 1000) / (√3 × I × PF)
Conversion Formulas
Single-Phase System
V = (P(kW) × 1000) / (I × PF)
Three-Phase System
V = (P(kW) × 1000) / (√3 × I × PF)
Where:
V = Line Voltage in Volts (V)
P = Real Power in Kilowatts (kW)
I = Load Current in Amperes (A)
PF = Power Factor (0.1 - 1.0)
√3 ≈ 1.732 (Three-phase constant)
kW
Rated real power from switchgear nameplate
Amps (A)
Determines the applicable conversion formula
PF
Volts (V)
Apparent Power (kVA)
Calculated voltage matches standard 230V single-phase system
Switchgear Voltage Analysis
Input Power
0.0 kW
Real power input
Load Current
0.00 A
Operating current
Calculated Voltage
0 V
System line voltage
Apparent Power
0.00 kVA
Required kVA capacity
Switchgear Sizing Insights
Switchgear kW to Volts Reference Table (PF = 0.85)
| Power (kW) | Current (A) | 1Φ Voltage (V) | 3Φ Voltage (V) | Apparent Power (kVA) |
|---|---|---|---|---|
| 5 kW | 25 A | 235 V | 407 V | 5.9 kVA |
| 10 kW | 50 A | 235 V | 407 V | 11.8 kVA |
| 20 kW | 100 A | 235 V | 407 V | 23.5 kVA |
| 50 kW | 200 A | 294 V | 509 V | 58.8 kVA |
| 100 kW | 400 A | 294 V | 509 V | 117.6 kVA |
Voltage Calculation Fundamentals
Voltage is inversely proportional to current for a given power: higher current means lower voltage (at constant power). Key Relationships:
- Constant power: I ↑ → V ↓; I ↓ → V ↑
- Constant current: P ↑ → V ↑; P ↓ → V ↓
- Three-phase voltage is √3 times single-phase voltage for same power/current
- Lower power factor requires higher voltage for same power/current
Switchgear Voltage Considerations
Switchgear must match system voltage to ensure safe operation and avoid equipment damage. Critical Factors:
- Nominal voltage rating must match calculated system voltage
- Voltage tolerance typically ±10% for industrial switchgear
- Three-phase switchgear is rated for line-to-line voltage
- Voltage drop in cables affects actual operating voltage
Switchgear Voltage Sizing Tips
Select switchgear voltage rating 10-15% higher than calculated voltage
Verify compatibility with upstream transformer voltage
Consider voltage drop in distribution cables (typically 2-5%)
Use three-phase systems for power >10 kW to reduce current and cable size
Improve power factor to reduce required voltage or current
Standard voltages: 230V (1Φ), 400V (3Φ), 480V (3Φ), 600V (3Φ)