63 kW 220v power supply belongs to the single-phase load, if the motor power and supply voltage is known, then the single-phase load current calculation formula is: P = UIcosφ, phase current I = P / Ucosφ; where: I for the phase current at the same time is equal to the line current, P is the power of the motor, U for the phase voltage, cos φ is the power factor of the motor, usually take 0.85. So the single-phase current I = P / U / cosφ = 63000/220 / 0.85 ≈ 336.9A; choose the leakage protector rated current should be 1.1 ~ 1.5 times the calculated current, I = 336.9 × 1.2 ≈ 404A.
Leakage protector, referred to as the leakage switch, also known as the leakage circuit breaker, mainly used in the equipment leakage faults as well as for the There is a fatal danger of personal electric shock protection, with overload and short circuit protection, can be used to protect the line or motor overload and short circuit, can also be used as a line under normal circumstances, infrequent conversion start. For the rated voltage of 220V or 380V fixed electrical equipment (such as pumps, compressors, agricultural electrical equipment and other electrical equipment easily accessible to people), when the metal shell grounding resistance of 500 ohms or less, a single piece of electrical equipment can be used for the rated leakage action current of 30 ~ 50mA, <0.1S action of the leakage protector, for the rated current in more than 100A For large-scale electrical equipment or power supply lines with multiple electrical equipment, you can select the rated leakage action current of 50~100mA fast-acting leakage protector. When the grounding resistance of the electrical equipment in 100 ohms or less, can also choose 200-500mA fast-acting leakage protector.