Does connecting two power supplies to the wiring box of the fire pump motor enable reduced-voltage starting?
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Does connecting two power supplies to the wiring box of the fire pump motor enable reduced-voltage starting? At what power level or above is this necessary?
Check the power rating; it might also be a dual-cable feed
No, dual power supply is achieved by using a switch to cut off the power, rather than connecting two power cables to the motor.
Generally, voltage reduction is used for starting; when the power exceeds 22 KW, reduced-voltage starting is applied. The current at the moment of direct starting is usually 5-7 times the motor’s rated current. The impact on the motor windings is very significant. Generally, motors over 15 kilowatts require reduced-voltage starting. Voltage-reduced starting involves changing the motor’s starting mode through circuit control and the addition of additional equipment, allowing the motor to start at a low speed first and then at a higher speed, thereby reducing the impact on the motor.
It basically won’t be a dual-wire connection; it should be a star-delta starting configuration with two wires, used to reduce the starting current. As for the power level to be used, there is no fixed rule; it should be determined based on the torque and current that the motor can handle, as well as according to the requirements of use and design. As long as the starting process does not cause effects on the power grid that exceed the limits specified by regulations (mainly voltage drops), it can be started directly; however, this also depends on whether the motor’s manufacturing process permits direct starting.
It should be voltage-reduction starting; motors used in **industrial applications generally employ this type of voltage-reduction starting, especially those with a power rating of over 75 KW