How is the status of the pump control column implemented in DCS and SIS? How are the start/stop signals for pump motors obtained and displayed in the DCS?
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1. For the pump units equipped with interlocks at present, it is necessary to switch the control lever to the automatic mode on-site in order to enable automatic start-up or shutdown. To facilitate internal operators in monitoring the status of this control lever, the desired functionality is as follows: For all pump units that can start up and shut down automatically via interlocks, the mode status of the control lever (automatic, stopped, running, locked) should be displayed in the DCS, and the operation details (the time at which the mode changed) should be recorded in the operation logs. How can this functionality be implemented? 2. The start/stop signals for the pump (green indicates operation, red indicates stop) are used to monitor the status of which component – the status of the contactors in the main circuit (primary circuit)? Manager Discussion Group
Color blocks, flashing, text alerts.
Pump with interlocked automatic start and stop
This can be achieved very easily by adding detection devices
What should be monitored is the status of the relays in the start and stop circuits
1. For all pumps and motors equipped with interlocked automatic start/stop functions, it is necessary to display the gear position status of the control lever (automatic, stopped, started, locked) in the DCS; therefore, the gear position status of the control lever must be integrated into the DCS system for display, via DI points； Record the operations in the operation log (indicating the time and second when the gear changes), and make records of status changes or alarms at the DI points of the DCS, noting the time and second when the DI signal’s gear changes. 2. The start/stop signals for the pump (green indicates operation, red indicates stop) generally use the auxiliary contacts of the contactors in the main circuit (primary circuit). If there are any other special requirements, the corresponding signal can be referenced.
Learning this is still achievable
Come in and learn it*; it’s achievable – it just involves a few on/off signals.
1 Among the systems I have worked on, I have never seen any need to monitor the status of the on-site control panels; introducing such signals into the DCS will undoubtedly increase its load. If monitoring is really necessary, then just add cameras and use a hard drive to store the recordings. 2 The operation signal of the pump that we see comes from the normally open dry contact signals of the AC contactors in the motor control circuit; this should be referred to as the secondary circuit. If the motor circuit is called the primary circuit, then what is it called?