Correct circuit breaker for small single phase pump motors

[ians]

Just for interest sake, I am using two raspberry PI's with expansion boards to control things. One for the irrigation control and one for the logic and remote switching of the purification system.

Silly question... why 2 Rasberry and not just an Arduino?

What i understand of these units...the rasberry PI is a general purpose computer and the other (Arduino ) is a microcontroller?

I would be interested to see how you control this system.

Something else that is a consideration...control circuit voltage... i know with the large water treatment works...the control voltage is generally 24 VDC because of the PLC control.

However on smaller plants...machines etc where there is no PLC ...just relays...level... pressure and limit switch control...12/24/110 and 230 volts is common...in fact many of the machines i work on...sometimes have 3 or 4 different control voltages.

[mygoggie]

Silly question... why 2 Rasberry and not just an Arduino?

What i understand of these units...the rasberry PI is a general purpose computer and the other (Arduino ) is a microcontroller?

I would be interested to see how you control this system.

Something else that is a consideration...control circuit voltage... i know with the large water treatment works...the control voltage is generally 24 VDC because of the PLC control.

However on smaller plants...machines etc where there is no PLC ...just relays...level... pressure and limit switch control...12/24/110 and 230 volts is common...in fact many of the machines i work on...sometimes have 3 or 4 different control voltages.

No question is silly.

The one PI is used as the computing system for an Opensprinkler irrigation controller expansion board. This is 24VAC as the solenoids and the controller itself uses 24VAC. This to form part of the system as all household greywater and waste water from the purification system will go into the garden via an irrigation network.

The second PI is used in the same way, but with another RIO (Raspberry input output) expansion board for which I have written most of the C++ code to control circuits of a research biogas digester I have designed and built. This RIO can accommodate 8 to 40VDC operating voltage. Fact is I have stock of this so why not put it to use? I can just as well change this into an Ardinio of a PLC unit if this does not work in the long run.

Then obviously there is 230VAC in the cabinet for the pumps and the ozonator. I would like to stick to 24V and 230V to keep things simple and to a standard.

For now I would like to see version 1 of the skid up and running which will allow me to change and improve on the design as data is gathered. No system is ever perfect and the best route is just to get it working and then refine the design until you get to a durable and lasting system. Just my design philosophy.