1

I currently have a 5 ton 220/3 phase AC unit. I have an opportunity to get a newer model 13ADN60A01 RUUD unit at a very reasonable price. However, the 13ADN60A01 unit is a 460/3 phase unit. My power source only has the 220 stinger. Is there a way to hook this 460/3Ph to a 220/3Ph source or should I just pass up this incredible deal? By incredible, I mean a 6 year old unit for free. So I do have some room financially to purchase some parts that would make this unit work (if those parts are available). IE: A small transformer?

BTW - I also ran a 220 single phase wiring combination to the location where the AC unit is located. I was told that 220/3Ph units are no longer available in a 5 ton and that "when the time comes" I would have to replace my existing unit with a 220 single phase unit.

1
  • I take it your existing 3 phase service is high leg delta? What gauge is the existing branch circuit and what amp rating is the existing breaker? Commented Dec 7, 2021 at 2:55

1 Answer 1

2

That model number actually says it all:

13A             13 SEER (13 BTU per watt)
   D            460V delta
    N           3rd generation, R410A freon (ready for that?)
     60         60,000 BTU (5 ton)
       A        metal chassis
        01      Series = "Rheem Value" 

Perfectly modern respectable unit.

Let's talk about what that means for power. 60,000 BTU / 13 BTU/W = 4615 watts

(or 1540 W per phase)

4615 watts at 480V 3-phase = 5.6 amps per phase. Uses #14 wire.

1.5 KVA is a size of an inexpensive transformer. Larger transformers would also suffice, and those are seen on Craigslist from time to time. You might be able to convert 240V 3-phase "delta" to 480V 3-phase "delta" with 3 of them. It's fine if your 240V is a wye configuration, wire the transformers like it's delta and it'll work fine. You'll need to get an electrician to help you wire that.

If you are stepping up 240V to 480V that means 240V amps double to 11.2 amps. We need to derate that 125% to 14.0 amps, and that just fits on a 15A breaker.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.