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Changing an AC Package Unit 460 v 3 Phase to 230 v 3 Phase

11/14/2017 10:58 PM

Hello can I change an air conditioner package unit 460v 3 phase to 230v 3 phase ?? Any ideas on how

thanks in advance

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#1

Re: Changing an ac package unit 460v 3 phase to 230v 3 phase

11/14/2017 11:01 PM

Yes you can with a transformer, BUT!!! transforming voltages cause losses, you must pay the loss.

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#2

Re: Changing an ac package unit 460v 3 phase to 230v 3 phase

11/14/2017 11:08 PM

The unit may already be operable on either voltage. Consult the nameplate and/or mfr.

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#3

Re: Changing an ac package unit 460v 3 phase to 230v 3 phase

11/14/2017 11:21 PM

First check to see if it is dual voltage option....

If not.....Figure out your total wattage and get a step-up transformer maybe....

http://www.ebay.com/bhp/460v-transformer

http://www.practicalmachinist.com/vb/transformers-phase-converters-and-vfd/240-3ph-460-3ph-177756/

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#4

Re: Changing an ac package unit 460v 3 phase to 230v 3 phase

11/15/2017 12:24 AM

If you have 460/480 volts, why would you cut the voltage in half? Your doubling your current draw which = twice the running cost. Buy a unit that's rated for your power supply, it's cheaper that way.

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#7
In reply to #4

Re: Changing an ac package unit 460v 3 phase to 230v 3 phase

11/15/2017 5:53 AM

You don't pay the electricity bill based on current - it's power (roughly volts x amps). Halve the voltage, double the current, same power.

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#13
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Re: Changing an ac package unit 460v 3 phase to 230v 3 phase

11/16/2017 12:43 AM

Correct, although the higher current required by the lower voltage will require heavier wire/cable, and will have somewhat higher I2R losses.

I presume that the OP is asking this because he obtained an A/C unit intended for 460V operation, and has only one of the several voltages around 220V available.

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#5

Re: Changing an ac package unit 460v 3 phase to 230v 3 phase

11/15/2017 12:59 AM

460V 60Hz can be the line voltage for an installation in the USA.

I guess you need phase voltage similar to the phase voltage in Europe: 230V 50Hz (since there is no equipment I have heard of that will use 3 phase 230V line voltage)

Check a few things first:

  1. Does your 3 phase system have a neutral point?
  2. Does your load admit 270V 60Hz?

If the anwer to both is yes, you can hook up your load there for free. End of problem.

However, if your load does not have neutral point or if it requires lower voltage, you will need a line frequency transformer, either single phase or three phase, depending on your load.

Moreover, if you need to change from 60Hz to 50Hz line frequency (no matter how unlikely that is), you will have to pay even more for switched inverters.

So, which one is your case?

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#6

Re: Changing an ac package unit 460v 3 phase to 230v 3 phase

11/15/2017 3:00 AM

Yes, indeed. Start by reading the manufacturer's operating instructions that came with the thing when it arrived. If these are not to hand, then a telephone call to the manufacturer is the next step, as this act may well precipitate its arrival. Go from there.

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#8

Re: Changing an AC Package Unit 460 v 3 Phase to 230 v 3 Phase

11/15/2017 9:24 AM

No you cannot.

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#14
In reply to #8

Re: Changing an AC Package Unit 460 v 3 Phase to 230 v 3 Phase

11/16/2017 1:24 AM

my thoughts exactly.. Why would you want to do it?

OP what reason do you have for wanting to change?

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#9

Re: Changing an AC Package Unit 460 v 3 Phase to 230 v 3 Phase

11/15/2017 9:27 AM

Carnac says the answer is to hire an electrician. They will understand both the needs of the air conditioner and the resources available to power it.

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#10
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Re: Changing an AC Package Unit 460 v 3 Phase to 230 v 3 Phase

11/15/2017 9:40 AM

Isn't that what the mayonnaise jar note just above your comment stated?

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#11
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Re: Changing an AC Package Unit 460 v 3 Phase to 230 v 3 Phase

11/15/2017 9:45 AM

We agree!

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#12

Re: Changing an AC Package Unit 460 v 3 Phase to 230 v 3 Phase

11/15/2017 11:33 PM

Joseplayer,

Welcome to the forum. Short question, but you can see from the replies that more information would help to give you an accurate answer. Generally, air conditioners use hermetically sealed compressors, so if the compressor motor is rated for both voltages then you are nearly home; if not--the cost of replacing the compressor is not worth pursuing. The controls usually operate at a lower voltage, such as 24VAC or similar. The small transformer that provides this may have a 230V winding in addition to the 460V winding on its primary; if so again this is simple.

However there are more things to look at--the contactor that supplies power to the compressor will probably have to be changed because the current draw at 230V will be twice what it was at 460V. Likewise, overcurrent protection (if any exists) will need to be sized at twice its former value. Line terminals will probably be too small, and the wire bending space for entering conductors will probably be too small (unless the 230V conductors are run in parallel.

Finally, you have the condenser fan motor to think about, same as for the compressor.

In my opinion, if all the above are OK, you have invested a lot of time and trouble into it, and I don't think it is a good change to do (but not a bad academic exercise). One suggestion in a couple posts was to get a step-up transformer sized for the load.

No matter what, hire a good electrician.

--John M.

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