Problem with motor stopping
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The device is equipped with a tank; in SIS, the motor stops when the liquid level in the tank falls below 10%. Normally, when there is liquid in the tank, the motor is turned on to pump it out; when the liquid level drops below 10%, the pump motor stops automatically. On the motor control panel on site, there are options for local and remote operation. When the button is set to local mode, liquid level signals are sent when the level in the tank is high; but does the motor keep running when the tank’s liquid level is below 10%? Please share your thoughts, thank you
For such matters, it is best to consult the electrical and instrumentation technicians at your own organization, or turn to relevant technical departments such as design institutes or the equipment department of your organization, for reference.
It can be designed with or without a stop; first check the drawings
This type of motor has interlocked shutdown and interlocked startup functions. When the operation column is set to local mode, the interlock does not function. The interlock shutdown is independent of whether the control column is local or remote; it is achieved through low-voltage secondary shutdown
Level control is generally achieved through a DCS, that is, via interlocks; therefore, remote and local modes are provided on the local control panel. When in local mode, the start and stop of the motor can only be controlled through the control panel. The chaining won’t work anymore. This is just a general design idea; the specific details depend on the control schematic in the drawings.
The views expressed above represent the general situation, and the analysis is quite thorough. As for this specific SIS, it is necessary to examine the electrical control schematic diagrams and instrument connection diagrams in order to determine the details
First, the SIS level interlock is activated; furthermore, in cases where a 400V system is used for control, the low level interlock is generally connected in series within the KM actuation circuit as a shutdown interlock with a higher priority. For a high-voltage 10 kV pump, it is only necessary to parallel the shutdown interlock pulse to the trip circuit. However, when the liquid level is restored, be sure to manually verify whether the SIS interlock has been released.