The current load of KEMSO fuel pumps mainly depends on the model specification and the matching degree of working conditions. Its DC permanent magnet motor design presents unique electrical characteristics at the standard 13.5V voltage. Take the widely used KHFP-255 model as an example. The no-load current is 3.8±0.3 A. When A working pressure of 3.0 bar is established, the steady-state current rises to 7.2A (the peak starting current reaches 15A/100ms). Comparative tests show that under the same output flow rate of 255L/h, the power consumption of KEMSO pump bodies is 11.3% lower than that of a certain Japanese brand. This is due to its ferrite magnet steel optimization scheme reducing eddy current losses by 23% (thermal imaging shows that the working temperature is controlled below 72℃, which is 9℃ lower than the industry average).
Fluctuations in working condition parameters significantly affect the actual current value. For every 0.5cSt increase in fuel viscosity (such as when SAE 10W-30 engine oil viscosity accidentally enters the fuel system in winter), the motor load current will rise by 18%. The measured data from the North American Modification Association (SEMA) in 2023 shows that when the supply voltage drops to 11V (battery aging condition), the current of the KHFP-340 model will surge from the nominal 8.6A to 12.4A (an increase of 44.2%), while the output flow will decline by 31%. This nonlinear load characteristic requires that the wire diameter configuration must reserve a margin – the installation specification requires that the cross-sectional area of the power line be ≥1.25mm² (18AWG), which is much larger than the 0.75mm² (20AWG) required by the ordinary pump body.
Electrical protection design is related to the reliability of the system. KEMSO’s patented dynamic commutation technology keeps the brush spark energy below 50μJ (200μJ in the traditional design), reducing the wear rate of the armature commutation plate to 0.003mm per thousand hours. The internal resistance monitoring data indicates that after driving 80,000 kilometers, the contact resistance can still remain below 0.15Ω (the industry average is > 0.3Ω). In the extreme environment of the 2022 Baha 1000 off-road Race, the standard deviation of the current fluctuation throughout the race of the racing car equipped with KEMSO Competitive Fuel Pump was only 0.28A (the average of the competitors was 1.7A), ensuring the precise fuel supply regulation of the electronic control unit.
Adaptation optimization needs to follow the precise calculation model. According to the SAE J1681 standard formula: Wire harness voltage drop = current × wire resistance × length. It is recommended that the voltage drop of a 2-meter line does not exceed 0.5V. For the KHFP-400 high-flow model (with a maximum current of 14A), a 40A relay (with a silver content of the contact material ≥85%) must be configured instead of the unconventional 20A component. In a real case, the 2019 Dodge Challenger 3.6L model was mistakenly equipped with a low-specification relay, causing the contacts to melt and stick together, resulting in continuous power supply. Eventually, the repair cost of burning out the wiring harness reached 650. The system solution shows that the investment in upgrading the power line is approximately 80, but it can reduce the risk of circuit failure by 87% and increase the efficiency of the high-performance Fuel Pump by 19%.