Electric Motor Manufacturer - Motor Protection: 5 Questions, 5 Answers
I. Selection principle of motor protector
The Electric Motor
Manufacturer stated that the reasonable selection of the motor protection
device can not only fully utilize the overload capability of the motor, but also
avoid damage, thereby improving the reliability and continuity of the electric
drive system. The specific function selection should consider the value of the
motor itself, the type of load, the environment of use, the importance of the
main equipment of the motor, whether the motor exits the operation has serious
impact on the production system, and strive to be economic and reasonable.
2. Ideal motor protector
The ideal motor protector is not more functional,
nor is it more advanced, but should meet the actual needs of the site, achieve
uniformity of economy and reliability, and have a high performance-price ratio.
According to the actual situation of the site, the type and function of the
protector can be reasonably selected. At the same time, it is simple and
convenient to install, adjust and use the protector. More importantly, it is
necessary to select a high-quality protector.
3. Why is the protection of traditional protection devices not ideal?
The
traditional motor protection device is mainly a thermal relay, but the thermal
relay has low sensitivity, large error, poor stability and unreliable
protection. The same is true. Although many devices are equipped with thermal
relays, the phenomenon that the motor is damaged and affects normal production
is still widespread.
4. Why is the current motor easier to burn than in the past?
Due to
the continuous development of insulation technology, in the design of the motor,
it is required to increase the output and reduce the volume, so that the heat
capacity of the new motor is getting smaller and smaller, the overload capacity
is getting weaker and weaker; The motor often runs in various ways such as
frequent starting, braking, forward and reverse rotation, and variable load,
which puts higher requirements on the motor protection device. In addition, the
application of the motor is wider, and it often works in extremely harsh
environments, such as humidity, high temperature, dust, corrosion and other
occasions. All of this has caused the current motor to be more susceptible to
damage than in the past, especially for faults such as overload, short circuit,
phase loss, and broom.
5. Development status of motor protection
At present, the motor
protector has developed from the past mechanical type to electronic and
intelligent type, which can directly display the current, voltage, temperature
and other parameters of the motor. It has high sensitivity, high reliability,
many functions, convenient debugging, and the types of faults after protection
action are clear at a glance. It not only reduces the damage of the motor, but
also greatly facilitates the judgment of the fault, which is beneficial to the
fault handling at the production site and shortening the recovery production
time. In addition, the motor eccentricity detection technology is used to
perform the motor eccentricity detection technology, which makes it possible to
monitor the wear state of the motor online. The curve shows the trend of the
eccentricity of the motor, and it can be found early that the bearing wears and
the inner circle and the outer circle are faulty. Early detection, early
treatment, to avoid broom accidents.
