What is the reason for the increase in the current of the 15kw water pump star delta start up operat

15kw water pump star triangle start.

The reasons for the increase in operating current are:

1. Under normal circumstances, the power factor.

Optionally, the pump motor current is i=15000

2. If the three-phase is slightly unbalanced, according to the calculation rules, the maximum current is taken to calculate the power consumption, and the carrying power of the motor will be reduced accordingly.

3. Any motor failure will reduce the carrying power of the motor, and the power consumption of the motor should be increased in order to reach the power of the pump, and the current will become larger.

4. The internal fault of the water pump leads to an increase in power consumption, an increase in the power consumption of the motor, and a larger current.

In normal operation, it is a triangle, the power calculation formula: p=, the power factor cos is taken, then:

i=15000/(

Therefore, according to the rated load power, the current is, you are now about 20A, not yet the rated power, under normal circumstances, the heat will not be very large! So what you call "hot" can't be felt personally, you should measure the temperature, and under normal circumstances, there is no problem below 60 degrees.

Why angular connection, we all use the star connection, if it is indeed an angle connection, the current of 20A is also normal, a little larger than the rating, belongs to the normal range. Maybe there are too many pipe elbows and the head loss is too large, resulting in a higher output power than the rated amount. If you look at how much the outlet pressure of the pump is, is it much larger than the pump curve.

If so, it means that the water resistance mentioned above is large, resulting in a large motor.

Also, check for phase loss.

Use a megohmmeter to test whether the grounding and interphase insulation are qualified.

Summary. Answer: 1. The star-delta start-up fault is to turn the large-load motor back to the delta connection form after starting it by the star connection method, so as to reduce the impact of the large current on the power grid.

The star-shaped connection start is to change the original 380V voltage of the line group to 3 times higher than the original voltage, that is, the current flowing through the line group is reduced to 1 3 of the rated current, and the triangle is transferred after starting.

Answer: 1. The star-delta start-up fault is to turn the large-load motor back to the delta connection after starting it by the star-shaped connection method, so as to reduce the impact of the large current on the power grid. The star-shaped connection start is to change the original 380V voltage of the line group to 3 times higher than the original voltage, that is, the current flowing through the old mode of the line group is reduced to 1 3 of the rated current, and the triangle is transferred after starting.

Can you add, I don't quite understand it.

Answer: The clamp current meter should be used to detect whether the current of the motor is normal, and the general overload is caused by the high running current. Check again whether the empty opening configuration is reasonable, and the selection should be double the rated current.

If the operating current is too high, first check the interphase grinding resistance of the motor with a megohmmeter, such as the resistance of the motor to the ground and other parameters shall not be less than 1 megaohm.

The circulating water pump star triangle starts to run the current is unstable with youfeng, if you trip, you should modify the problem and explain the parameters of the brake, that is, the circuit breaker. We should also explain the motor parameters and contactor thermal relay parameters, so that we can analyze them in a targeted manner. If the wiring is correct, it is possible that the instantaneous protection current of the circuit breaker is small.

At the moment of star-delta switching, the motor loses power and the coil loses magnetism. When the contactor is re-energized after the switching, it is equal to the stator coil re-energized, so similar to direct start, there is an impulse current of coil magnetization, which can reach more than 12 times the rated current of the motor, and the circuit breaker should be able to avoid this impulse current, and its instantaneous protection value should not be less than 13 times the rated current of the motor triangle year-old operation. In the case of star start-up, because the coil voltage is low, the inrush current is also small, and it will not trip.

However, the delta operates at a high voltage and has a high impulse current, causing tripping.

Summary. After starting, the running current is unstable or high, mainly due to the following reasons: 1. The power supply voltage is not stable enough, and the power supply quality of the power supply voltage is not good, and the phenomenon of high and low occurs, which can lead to unstable current.

Too much load is connected separately from a certain phase, resulting in uneven three-phase load and unbalanced current. On the same line, there are other high-power electrical equipment in use. 2. There are poor contact phenomena in the line, such as contactor contact singeing or serious oxidation of cable joints, resulting in unstable current.

3. There is a short circuit between turns or layers of the motor winding.

Fourth, the mechanical resistance is large, resulting in high motor current. Resolution.

1. Readjust the delay action time of the time relay.

2. Redistribute the load of the line; Optimize equipment uptime in the same line.

3. Check the contactor contacts, cable joints and other parts, and deal with the problems in time.

4. Check whether the motor bearings and mechanical equipment are short of oil or jammed, and deal with them in time.

The circulating water pump star triangle starts and runs with unstable current.

After starting, the running current of the rotten is unstable or high, mainly due to the following reasons: 1. The power supply voltage is not stable enough, and the power supply quality of the power supply voltage is not good, and the phenomenon of high and low occurs, which can lead to unstable current. Too much load is connected separately from a certain phase, resulting in uneven three-phase load and unbalanced current.

On the same line, there are other high-power electrical equipment in use. 2. There are poor contact phenomena in the line, such as contactor contact singeing or serious oxidation of cable joints, resulting in unstable current. 3. There is a short circuit between turns or layers of the motor winding.

Fourth, the mechanical resistance is large, resulting in high motor current. Resolution.

1. Readjust the time relay to delay the time when there is no action time.

2. Redistribute the load of the line; Optimize equipment uptime in the same line.

3. Check the contact traces such as device contacts, cable joints and other parts, and deal with problems in time.

4. Check whether the motor bearings and mechanical equipment are short of oil or jammed, and deal with them in time.

Fellow, I really didn't understand, I can be more specific.

Find out.