Can I Use A PLC Instead of A Power Supply

Is the operation of this portable lift critical to human safety? I suspect it is because someone suggested that you use an uninterruptable power supply.

A PLC in my world is a programmable logic controller usually DIN-rail mounted. What is it in your world?

A PLC in my world needs a power supply to work, and it is not capable of providing power to anything all by itself. Yes, most PLC's are powered from 24 VDC power supplies which is fairly standard in industrial automation.

Will your lift work with 4-20 mA of power?

I would say no since they are two totally different things.

https://en.wikipedia.org/wiki/Programmable_logic_controller

Mousetraps, apples and #2 pencils are cheaper than a UPS, why not use one of those?

The point of that sarcasm is that what you are asking demonstrates that you have no clue what you are doing, and you are working on something that could, ostensibly, kill or injure someone. So assisting you further is in effect, aiding and abetting the commission of a crime.

I’ve been thinking of a suitable answer other than NO!

What you probably want is a battery with a charger. But you have scarcely defined your project at all.

<...We...> need to hire someone who knows what the <...We...> is doing. To sell design services without having either the capacity or the know-how is close to fraud in most jurisdictions.

We are designing a portable lift for a client.....We are not electrical engineers....

It sounds like there is a lot going on here and you are out of your depth (a PLC and power supply are totally different things). More than can be answered by an online forum.

Please get a local Electrical Engineer or electrician involved in this project as there are a number of safety systems and electrical and safety standards you need to comply with and include in your complete lift design system (as well as getting it to work electrically).

Safety first. If anything goes wrong YOU will be legally liable.