Starting methods for a 400KW electric motor?
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Hello everyone. For the project construction here, two pumps have been initially selected with a power rating of 400KW each. To be honest, we have no experience working with pumps of such high power; in the past, the factories used pumps with a power rating of less than 200KW, which were AC 380V motors that were started using frequency converters. I would appreciate some advice from those with more experience: should this 400KW pump use a motor powered by 380V AC? Should we still choose a 10KV high-voltage motor? (The factory has a 10KV power supply) What is the best starting method to use? ?
This should relate to the transformer capacity; it’s best to coordinate with the power supply side before making a decision, for reference only.
Unless your water pump is really close to the MCC cabinet, the cable setup will be a significant hassle.
250KW motor, 380V variable frequency soft start
Generally, for motors with a capacity of over 200 kilowatts, it is not advisable to use 400V equipment, unless there is no high-voltage power supply available. A 10kV motor with a capacity of 400 can generally be started directly; if there are restrictions imposed by the transformer at the power supply point, a solid-state soft starter can be used. If water consumption remains unstable over time, and energy savings during long-term operation are a concern, high-pressure frequency converters can be used. Personal opinion, for reference only.
Okay. Thank you for your analytical introduction. Let’s get a preliminary understanding of it. The 10 kV high voltage level exceeds the capabilities of our factory’s electricians; we need to have a design institute handle the design.
For the 400KW motor, a 10KV motor is selected; however, the starting method can only be determined after recalculating based on factors such as the power supply capacity and relay protection settings.
Okay, thank you for the advice. I’ll find out first; in the end, it’s still the design institute that will make the decision!
Hello, I would like to ask another question. For a 400KW pump, we use a 10KV motor. If the pump starts directly, it will begin rotating at full speed right away – could this cause too much stress on the pump and the pipes? Will this affect the pump’s lifespan? Could it cause the shaft to break? For this 400KW large water pump, if direct starting is considered, are there any special measures required for the inlet and outlet valves of the pump? ? I hope my friends can offer some advice!