With the large-scale integration of power quality-sensitive equipment in advanced manufacturing sectors, the conflict between the currently permitted short-term fault-tolerant operation of distribution networks and the voltage tolerance characteristics of sensitive loads has become increasingly prominent. Therefore, studying preventive economic optimization of sensitive equipment under low-voltage conditions during faulted operation of distribution systems, while accounting for losses of sensitive equipment, is of great significance. First, based on the symmetrical components method, the tripping criteria for adjustable speed drivers (ASDs) are quantified. Second, an operation cost optimization model for distribution networks is established, which incorporates the loss of sensitive equipment such as ASDs and programmable logic controllers (PLCs). Finally, a grid-connected ASD system is built in Simulink to verify the correctness of the ASD tripping conditions. Using a modified IEEE13-node system, three typical scenarios are comprehensively considered, namely, demand response behavior of industrial park loads, whether sensitive equipment such as ASDs and PLCs are equipped with energy storage devices, and whether uninterruptible power supply (UPS) systems are installed. These scenarios validate the accuracy and effectiveness of the proposed preventive optimization model.