Hello,

I have a need to start, and stop a diesel engine that we are using as a power unit.
I am thinking we can do this using a PLC, but I am by no means profecient with PLC's. Here is the info about this homade power unit.
It is an all mechanical 6V53 detroit diesel. This system will have to operate on only 12v DC. It will be out in a field with somewhat limited access.
So. I am looking for advice on the type and construction of what will be needed to make this work. And as usual the cost must be kept as low as possible, $3.00 corn does not buy much these days.

This power unit will be hooked up to a drainage pump connected to a float switch. we will have a solar powered 12v battery maintainer on it as well.

I have attached a basic flow chart as to what I am looking to do. keep in mind it is basic. I do have a very good CNC machining skills and have used robotics in my past, but never had the opportunity to get into PLC's much. I also understand basic inputs and outputs and so on.

Any and all help on this project will be greatly appreciated!

 

I have no idea what "murphy system" is?

I know your not generating electricity, but most generators have a "oil level" switch which prevents starting. After it starts, you can monitor oil pressure.

Quiescent current might kill you. The current drawn doing nothing unless you do something like the float latches the system (PLC) on (latching relay) and the PLC would turn it off (pulse) after it orderly shuts down the engine.

So, the idea is the float switch directly turns on the PLC, but when you open the switch, the PLC stays running. Think, "Dual coil

Not sure what you want to do about alarms, if any. Another float switch with a siren.

One float switch isn't going to work. You would need a low, and a high and maybe a safety. Your system would turn on at high and pump down to low unless this is some sort of irrigation and your guaranteed to have water, but even that has to be checked.

You might be better off with a solar charge controller, so your actually getting the voltage you need.

You can google "idec smart relay" and see if it might be suitable. You do need a "development kit". There are cheaper versions. Idec does have a free simulator so you can get your feet wet without a product.

There might be more involved with staring a diesel engine.