1. How many reasons does the UNT-MMI-B intelligent MCC control protection management device run after the power is turned on?
There are two situations that cause the device to run up and the light is on:
1. Check if the contactor normally closed auxiliary contact of the contact state of the device A (X3-9) is connected.
2. When the power supply of the device is DC, check the positive and negative poles of the power supply and connect them according to the correct polarity.
Second, UNT-MMI-B control protection management device during the startup process reported overload analysis?
1. Check if the rated current is set correctly and set the rated current according to the nameplate of the motor.
2. The external CT is not threaded as required. Check the size of Ia, Ib, Ic, I1, I2 to determine whether the line order is correct or not. If the phase sequence is wrong, I1 is small, and I2 is close to A, B, C or Very big).
3. Check the position of the transformer. The current contactor is connected between the molded case circuit breaker and the contactor. (If the current device is connected between the contactor and the motor, the positive transmission is normal, and the reverse relay may be phased. ).
Third, UNT-MMII-A common problems and operational precautions
1. Do not connect the power supply of the power cord of the device.
2. Pay attention to the setting of CT model when setting parameters.
3. When 4-20mA is set, the corresponding value of 4mA is set to 0, 20mA corresponds to 2 times of rated current, and the maximum range of DCS is consistent with the corresponding value of 20mA set by the device.
