Mitsubishi Q-series: Connecting an oil pump for remote control...

[Mas01]

We've got a portable cooling pump which circulates a coolant oil.
The spec says it can be remotely operated (coolant START/STOP), via a 3-pin connector:
[FONT=Calibri,Bold][FONT=Calibri,Bold]

[/FONT][/FONT]PIN A...+24VDC from pump supply
PIN B...Start by momentary connection to PIN A
PIN C...Stop by momentary connection to PIN A


QUESTION: To connect this to our PLC (Mitsubishi Q-series), do I need to connect wires B & C to a "QY18A 8 Relay Outputs" card (we have a spare channel), then create a "toggle" switch on the GUI to control the Start/Stop control? Thanks

 

[sczot]

hello,


just to be clear


you want to connect both wires (start/stop) to single PLC output and control functionality via some button on HMI?

 

[parky]

It will depend on the type of contacts are required i.e. N/O for both start and stop of is it N/O for start & N/C for stop (stops are N/C & you open them to stop it), however, it could be pulsed to start & pulsed to stop i.e. close them to start & stop.
You will need two outputs in reality although it could be possible to use the one if the internal logic allows (this is assuming the Stop needs to be N/C for the pump to run).

So there are 3 possibilities
Two outputs required

24v---------+-------| |-----------START Pulsed to start or on to start
|
|--------------------| |-----------STOP Pulsed to stop or on to stop

If Stop is N/C then two outputs required
24V------------------| |----------START ON To start
|
|----------------------| |------------STOP On to enable Start (off for stop)


Or maybe if only one output available then
then one output drives a relay with a N/C & N/O output i.e. it switches from one state to the other it will depend on how the pump logic works.

 

[Mas01]

Thanks again. The wording in the spec ("momentary connection") to me would suggest a pulse for start and pulse for stop (closed momentary contact for start and stop), so your code might work here.