If the opening and closing speed of the valve is too fast, it is easy to cause water hammer. Therefore, the appropriate opening and closing speed should be selected according to different operating conditions. Electric actuators know that valve electric equipment has its special requirements, that is, it is necessary to restrain torque or axial force. Generally, the valve electric equipment uses a coupling that constrains torque. When the electric equipment standard is determined, its control torque is also determined. Generally, it works at a predetermined time, and the motor is not overloaded. However, if the following conditions occur, it may lead to overload: First, the power supply voltage is low, the required torque is not obtained, and the motor stops rolling; secondly, the torque constraint organization is set to be greater than the suspended torque. Forming a sudden over-torque to make the motor stop rolling; the third is intermittent use, the heat accumulation of the attack exceeds the allowable temperature rise of the motor; the fourth is the torque constraint of the tissue circuit for some reason, causing the torque Too large; the fifth is to use the ambient temperature is too high, so that the heat capacity of the motor is reduced.
QOTO maintains the motor by using fuses, overcurrent relays, thermal relays, thermostats, etc., but these methods have their own advantages and disadvantages. For the variable load equipment of electric equipment, there must be no reliable maintenance methods. Therefore, it is necessary to adopt various combinations, and there are two types that can be summarized: one is to discriminate the increase and decrease of the input current of the motor; the other is to discriminate the heating condition of the motor itself. The electric actuator suggests these two methods, regardless of the moment when the motor heat capacity is given.
In general, the fundamental maintenance method for overload is: use the thermostat for overload maintenance of the motor for continuous or jog operation; use thermal relay for maintenance of motor stall; use fuse or overcurrent relay for short circuit accident.