Selection method of intelligent motor protector and how to solve overload
There is no uniform standard for motor protection products on the market, and there are various models and specifications. In order to meet the different needs of users, manufacturers have derived many series of products, and the wide variety of products brings a lot of inconvenience to the selection of users. Users should fully consider the actual needs of motor protection when selecting models, and reasonably choose protection functions and protection methods. To achieve a good protection effect, improve the reliability of equipment operation, and reduce losses.
Intelligent motor protector manufacturer tells you the basic method of relay selection
The selection of motor protection depends on how to use the motor and the protector reasonably. The following conditions and factors related to protection are provided to provide a reference for users when selecting models.
1. Motor aspects: the relay model specifications, motor functional characteristics, protection type, rated voltage, rated current, rated power, power frequency, insulation level, etc. to be understood first. These contents can basically provide users with a reference for how to correctly use and maintain and select the protector.
2. Environmental conditions: mainly refer to normal temperature, high temperature, high cold, corrosion degree, vibration degree, sandstorm, altitude, electromagnetic pollution, etc.
3. Motor use: mainly refers to the required characteristics of dragging machinery and equipment, such as fans, water pumps, air compressors, lathes, oil field pumping units, and other mechanical characteristics of different loads.
4. In terms of control system: the control modes include manual, automatic, local control, remote control, stand-alone independent operation, and centralized control of production lines. Start-up methods include direct, step-down, star-delta, frequency-sensitive rheostat, inverter, soft start, and other start-up methods.
5. Other aspects: whether the user's monitoring and management of on-site production is more casual or rigorous, the severity of the impact of the abnormal shutdown on production, etc.
There are many factors related to the selection of the protector, such as installation location, power supply, coordination with the power distribution system, etc.; it is also necessary to consider whether it is the protection configuration of the newly purchased motor, the protection upgrade of the motor, or the accident motor. The improvement of protection, etc.; the difficulty of changing the motor protection mode and the degree of impact on production should also be considered; the selection and adjustment of the protector should be comprehensively considered according to the actual working conditions on-site.
Intelligent motor protector: detects the three-phase current value, the protector uses a single-chip microcomputer to realize the intelligent comprehensive protection of the motor, integrating protection, measurement, communication, and display. The setting current is digitally set and operated through the buttons on the operation panel. Users can modify and set various parameters on the spot according to their actual use requirements and protection conditions.
What is the reason for the smart motor protector showing overload?
When the current exceeds the rated current for a certain period of time, the thermal relay will act, an overload signal will be issued, and the indicator light will be on.
Check motor protector parameters:
(1) Whether the current and level of the built-in CT and the external CT of the motor protector are consistent. Solution: Inconsistent and replace the same CT or motor protector.
(2) Whether the rated current of the motor protector parameters is consistent with the rated current of the motor nameplate. Solution: inconsistent Set the parameters of the motor protector to be consistent with the rated current of the motor nameplate.
(3) Whether the overload current setting value and overload time setting of the parameters of the motor protector is appropriate. Solution: Set the motor overload current to 1.2 times the rated current of the motor when it is not appropriate; lengthen the overload time appropriately.
(4) Start the motor, compare the current detected by the clamp ammeter with the current detected by the motor protector and confirm whether the working current is within the rated current range of the current. Solution: In case of overload, check or overhaul the motor.
Intelligent motor protector overload solution:
(1) Replace the consistent CT or motor protector.
(2) Set the parameters of the motor protector to be consistent with the rated current of the motor nameplate.
(3) When the overload current setting value and overload time setting of the parameters of the motor protector are not appropriate, set the motor overload current to 1.2 times the rated current of the motor; the overload time is appropriately extended.
(4) Start the motor, and compare the current detected by the clamp ammeter with the current detected by the motor protector, the working current is not within the rated current range of the current, and the motor should be checked or repaired immediately.