Precifarm Agent
Interactive engineering workspace.
Change the brief and watch the engineering tools work it through: energy, charge time, protection and cable, with every step in the trace.
Project brief
3-bedroom house in Nairobi, single-phase supply, power cuts most weeks.
Daily driving
- 1Daily EV energy14.4 kWh
- 2Overnight charge time2 h 17 min
- 3Circuit protection40 A + RCD
- 4Cable check2.48% drop
- MeterKenya Power
- 40 A MCB30 mA RCD
- 6 mm² Cu25 m · 2.48%
- Pulse7 kW
- EVType 2
Calculation trace
calculateEvEnergy(dailyKm: 80, kwhPer100km: 18)
80 km/day at 18 kWh/100 km gives 14.4 kWh/day at the battery.
calculated
calculateChargingTime(kwh: 14.4, chargerKw: 7)
14.4 kWh at 7 kW takes 2.06 h ideal, about 2.29 h with 90% efficiency.
calculated
sizeProtection(loadKw: 7, system: single-phase, isEvCharger: true)
7 kW single-phase at 230 V draws 30.4 A, 38 A with the 1.25 continuous factor. Breaker: 40 A, plus 30 mA RCD (Type A + 6 mA DC detection, or Type B).
calculated
calculateVoltageDrop(currentA: 30.4, lengthM: 25, system: single-phase, csaMm2: 6)
6 mm² copper: 5.7 V drop (2.48%), within the 5% limit. 30.4 A over 25 m (single-phase, copper) needs at least 2.97 mm² for ≤ 5% drop; smallest standard size that passes: 4 mm².
calculated
- Assumes 18 kWh per 100 km and a 25 m run from the consumer unit. A site survey confirms the supply, earthing and cable route.