what is DI and DO for motor of pump?

[mohdalharbi]

for motor of pump usually there is:
start (DO go to the contactor)
stop (DO go to the contactor)
status (DI from the relay of a contactor or from
protection relay)
failure (DI from the relay of a contactor or from the
protection relay)

there is also signal from a circuit breaker.
i want confirmation from the expert people and correction if there is mistake in the above statements.
thnks

 

[ScottyUK]

D.O. - Digital Output (from your controller)
D.I. - Digital Input (to your controller)

In the D.O. case, your controller will probably provide a volt-free relay contact to control your equipment. In the D.I. case, you will need to provide a volt-free contact to the controller from your equipment. The signal from the circuit breaker will be a similar contact connected to another D.I. on the controller.



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[buzzp]

There could be more. What is the pump motor doing? Different industries have different requirements. For example, oil pumping applications typically have a run, stop, and pending start light (motor tripped on OL but will try to restart after restart delay). You may also want indication as to what it tripped on, like underload (loss of fluid) overload, etc..

 

[bmsg]

There can be any number of DIs and DOs for the running of a motor from a PLC, depending on the application, control philosophy, etc. For example, it might be something like this:
1. DI from MCC to PLC stating that control circuit of motor is healthy.
2. DO from PLC to MCC that all start permissives are satisfied
3. DO from PLC to MCC to start motor(i.e., pump).
4. DO from PLC to MCC to stop motor
5. DI from MCC to PLC indicating that motor has started.
6. DI from MCC to PLC indicating motor has tripped.
7. DI from MCC to PLC indicating motor has stopped
8. DI / DO from PLC indicating that motor is in remote operation mode.
9. DI / DO from PLC to MCC indicating motor is in local operation mode,

etc.

Obviously, how many DIs / DOs are required depends on your application.