UPS电池容量计算器 — 公式
## Ground Fault Current Estimation
Ground fault current flows when a live conductor contacts grounded metal. Its magnitude determines how quickly protection devices clear the fault.
### Formula
**I_gf = V_phase / (Z_ground + Z_source)**
**Touch Voltage = V_phase x Z_ground / (Z_ground + Z_source)**
Low ground-path impedance ensures high fault current, which trips protective devices quickly. High impedance (poor grounding) results in low fault current that may not trip the breaker, leaving a dangerous condition.
Ground fault current flows when a live conductor contacts grounded metal. Its magnitude determines how quickly protection devices clear the fault.
### Formula
**I_gf = V_phase / (Z_ground + Z_source)**
**Touch Voltage = V_phase x Z_ground / (Z_ground + Z_source)**
Low ground-path impedance ensures high fault current, which trips protective devices quickly. High impedance (poor grounding) results in low fault current that may not trip the breaker, leaving a dangerous condition.
计算示例
277 V phase-to-ground, 0.5 ohm ground path, 0.1 ohm source impedance.
- Ground fault current: 277 / (0.5 + 0.1) = 461.7 A
- Fault power: 277^2 / 0.6 = 127,882 W
- Touch voltage: 277 x 0.5 / 0.6 = 230.8 V (dangerous)