Can I use a single phase UPS for a three phase knitting machine?

Question

I want to use a UPS for my three phase automatic knitting machine of 2.5kva. For that I need to have atleast 3 kva UPS.I cannot afford a three phase online UPS being very expensive. Please advice if i can use a 3kva single phase online or offline UPS for my knitting machine. I could not decide as nothing has been mentioned in the technical manual of the machine. Please advise...

Answer 1

Three phase and single phase AC are two very different animals. You can't use a single phase UPS in place of a three phase UPS just because it has enough power. Also, there are two types of three-phase wiring -- delta and Y. That makes a difference, too.

However, if you are only concerned about keeping the contents of your machine's controller, you might be able to use a UPS. Digital devices use DC for power, so it's likely that the controller has a power supply connected to a single phase of the three phase. You might be able to put a UPS between the controller power supply (plug) and the single phase power (socket) -- but it will take some digging into the manuals to see if it's really OK to do that.

Answer 2

Just saying 3 phase isn't enough - you have to say the voltage, which will then tell those who are knowledgeable the voltage between the phases. And as stated, you need to know if you have a neutral available and you have to say what the welder is labeled for.