This is a part of an email I've sent to a manufacturing manager of a plant that contacted me for a quote of automating his manufacturing plant. I basically explain the scope of work and various phases he could expect to take place if the decides to hire us to help him automate the production. This is my email:
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Regarding your plant specifically, I first would need to understand what kind of process it is to be able to suggest a rough automation system architecture.
On the other hand, when automating existing processes (production lines, machines), it comes down to incorporating a PLC (programmable logical controller) as a heart of an automation system. And possibly VFDs (variable frequency drives) in case it is necessary to vary the rotational speed of the electric motors (e.g. pumps, fans etc.). Other equipment that might need to be added are possibly sensors (measuring instruments for various media or position sensors - to read out the position of elements on the production line - as a reference for the PLC program). The last thing that might need to be addressed is a machine safety system and this can be covered within the same PLC system (a PLC that can accept safety signals and turn off actuators safely) or as a dedicated system with its own controller or a number of safety relays.
The brand of the PLC and the specific series of the PLC within the brand depends on the size and complexity of the process that requires automation. For smaller applications (e.g. standalone machines) it is enough to incorporate an entry level PLC system and then for bigger system a cluster of smaller PLC's or a larger (more capable) PLC system if the process has to be controlled as a unit (cannot be broken into functional groups - e.g. standalone processes independent of each other).
Generally, the choice of equipment should be made through 3 important aspects:
- quality of equipment - proven manufacturers
- price
- availability (often overlooked but very important) - time of delivery of spare parts / replacements
This might seem complex to you at first but I assure you that what I have stated above is fairly easy to plan and implement.
The Industrial Packaging Machine course you took on my website is exactly your case. We took and existing machine (the mechanics had still plenty of life left inside) and inspected the electrical equipment (actuators and sensor talking from the automation perspective). Based on the list of actuators (motors) and sensors (end switches, photoelectric sensors) we then created an electrical project (drafted in Eplan Electric P8). This project was the central point out of which the PLC programmer could write his code for the machine and the panel builder could build an electrical panel with all the necessary equipment inside (PLC, power distribution, VFDs etc.).
We then transported the electrical panel to the factory, the site team pulled the cables from the machine to the cabinet, the PLC programmer wrote the program and then we commissioned the whole system.
This basically describes the process that could take place also in your case.
Here are the phases:
1. Site inspection for a particular machine/production line - listing all actuators and sensors and writing a functional description of the machine (this would in large be an assignment for your team from the plant since you understand the application. Important: For field devices and cables - decide whether to leave them or replace - this applies in particular to cables if they are old (or overall in bad shape)
2. Creating a wiring diagram - thus determining the electrical panel size and all equipment inside, also to assess the price of the overall hardware necessary to automate the system in mind
3. Preparing hardware - electrical panels and field wiring
a) Building electrical panels in a workshop and transporting on the site (plant)
b) On-site activities - pulling cables to the location of the panel, possibly already connecting field devices before the panel arrives
4. Software engineering (writing PLC program) - this phase can start together or at latest after the point 2. Ideally, parallel to panel building to not waste time in the meantime
5. Commissioning - When all field devices (motors, sensors etc.) are connected on both sides (in the field and in the panel) the commissioning phase can take place. This generally means - checking the wiring and the wholeness of the system and then applying voltage to the whole system. Then the PLC programmer(s) fine tune the automation system and commission it.
6. The system is now in production and automated. The customer (plant) receives the as-built documentation (updated wiring diagram - electrical project), software code for the PLC (this is an option) and possible other documentation (per request/requirement) from the system integrator (PLC company). The customer is now ready to take over the automated system and signs an agreement with the system integrator that the job is done.
For smaller machines (such as the one you see in my course on the EEP academy) all these phases take altogether about 2-3 months from beginning until fully automating the machine.
You can hire separate companies to do various phases for you. Better option is to have everything done by one company - a turnkey solution for your system in the plant. This way everything comes from one company which then reduces a possibility for miscommunication.
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