The 11KW electric motor air switch burned out?

The main reason for this is that the wire is thin and the contact is not solid, and in addition, the leakage of the motor also generates heat. The first thing that needs to be solved is the motor, and when the single-phase winding of the motor is grounded, its voltage to the ground is 220V, so you measure it to 220VThe solution is to find the rewound coil for motor repair.

As for the incoming line, you should choose more than 10 square copper wires, and the connection line can not be less than 10 square meters, and the outgoing line must also be more than 6 square cables, because the motor starts frequently, its instantaneous current is 5-7 times the rated current, and your line obviously can't withstand such a large current. As for the air opening, the contactor can be selected as 100A. The thermal relay can choose 30a, and it will not work if it is large, the most important thing is that the contact points must be tightly connected.

1.The air switch is too big, so it doesn't jump. According to the working characteristics of the thermal relay, when the working current is 2 times of the rated current, the thermal relay will jump after a few minutes, and from the starting and working conditions of the motor, it is obvious that this condition is not available, therefore, the thermal relay does not jump.

2.The cables are all made of more than 6 square meters to make the bridge line.

For the air switch, it is recommended to use Changshu CM1-63M 33002 in 32A

The contactor is B45 of Shanghai People's Electric Appliances

The thermal relay is T45 18 27A3The motor has a phase winding insulation that is too low, and there is leakage. Workaround:

Disassemble the motor, take out the stator and end cap, and dry the stator. After processing, measure the stator winding of the motor with a shake meter, and then install it back for use when it meets the requirements. If the insulation does not meet the requirements, the motor winding should be rewound.

The third phenomenon clarifies the essence of the problem.

The motor has a relative insulation failure.

380V alternating current means that the voltage between the three phases is 380V, and the voltage to the ground of each phase is 220V.

Treatment: disassemble the motor wiring, use the shake meter to measure the insulation of the three sides, the 400V motor single relative insulation should be above Europe, the three corresponding roughly balanced, if it is found that there is a phase is significantly lower than the other two phases, it can be tested again after 24 hours of stand-drying, if there is still a problem. This relative insulation damage is almost certain.

If the insulation goes straight to 0, then it must be a breakdown. In the above two cases, the motor should be dismantled and checked.

As for the question of the empty open option. Actually, there is a manual for this. Personally, it seems that three times the rated current is a bit too much.

Twice as much, a little more, and you're fine. There is no conclusive question on this issue, depending on personal experience, in the operating environment that the landlord said, it is understandable to relax a little, otherwise once the selection is too small, the operator needs to frequently reset the thermal relay.

1> The air switch is too large. It is recommended to use DZ47-63 32A contactor, use CJ20-3210 or 4011 to open empty, and the reason for no tripping is that there is no overload. I didn't jump.

The temperature of the motor is 60-70 degrees for the normal range. If the E-class motor rises and stabilizes at 75 degrees plus the ambient temperature such as 25 degrees, the maximum temperature of the motor is 25 + 75 = 100 degrees. When it reaches 100 degrees, the motor will burn out.

The AC contactor can operate up to 600 times per hour.

It is recommended to use a larger cable. Because the motor is started frequently.

3> The insulation of the motor is faulty. Repairs are recommended. The resistance of the motor to the ground shall not be less than that of the ohm.

Let's not talk about the problem of electricity, everyone talked about it very well.

There is a problem with the whole process, since it is a frequent start, it should be installed on the power output side, that is, the clutch on the motor spindle, and the clutch is used to start the machine and stop the machine.

My machine is the main engine frequently starts and stops, there is always a strange problem, and then I changed the motor to start frequently, although there are fewer problems, but there are still there. Later, a clutch was added and there were no more problems.

The design of your machine is not reasonable.