Phase Converter

[mbox]

Hi there,

I am looking to run some of my Appliances that has 3 phase on a one phase line....i found this when googling and would like to aquire one of these : 3 Phase Converter

Anyone knows where i can get something like this in Thailand?

Thank you ,

Mbox

[tjo o tjim]

The unit you indicated is a motor-generator system, which isn't the most efficient or effective solution for long-term. A standard 3-phase UPS (without a battery if you wish) will be a better bet; you can single-phase the input as long as you de-rate the capacity of the system by about 35%.

[Crossy]

I'm sure a look round Chinatown with a Thai who knows what you're looking for will turn up the goods.

BUT.

It may be cheaper to simply replace the 3-phase motors in your kit with single phase units, heaters can be easily re-wired for single-phase operation.

What exactly do you need to run? If it has motors then I'm not sure Tim's UPS solution will work unless you have a well over-rated unit, switch-on surge may kill it

Obviously, the ideal solution (if you can't modify the appliances) would be to get 3-phase installed in your location.

[mbox]

Thanks for the replies Tim & crossy,

i have 12 aircons in the newbuilt home..2 of them are 3 phase ( each 35000 btu) all the others are single phase . So would like to run the 2 x 35000 BTU aircons on single phase too....any suggestions?

Thx, mbox

I'm sure a look round Chinatown with a Thai who knows what you're looking for will turn up the goods.

BUT.

It may be cheaper to simply replace the 3-phase motors in your kit with single phase units, heaters can be easily re-wired for single-phase operation.

What exactly do you need to run? If it has motors then I'm not sure Tim's UPS solution will work unless you have a well over-rated unit, switch-on surge may kill it

Obviously, the ideal solution (if you can't modify the appliances) would be to get 3-phase installed in your location.

[Crossy]

That's a pretty big house, you really need to do some proper load calculations. By the time you add on your water and pool pumps, lighting and kitchen equipment it's possible you won't be able to get a single phase supply big enough anyway. The biggest normally available single-phase supply is 45A although I believe some in some areas you can get a 100A supply.

Using the sizing tables on the site you reference. In order to run two 35,000 BTU A/C units drawing about 12 Amps (running) each you'll need at least a 10kW converter (to cover the start surge). The website prices this at US$1700 (55,000 Baht). Note that this unit IDLES at 4.5 Amps input current so you'll need some means of powering it off when it's not running the aircon if you don't want a massive power bill.

I would investigate:-

1. Swapping out the 3-phase units for single phase (they'll have a resale value so this may prove the most economical course of action), it's likely that only the outdoor units will need changing anyway, talk to your aircon man.
   
2. Getting a 3-phase supply (you may need it anyway)
   

Motors and generators are readily available all over the country, maybe a home-brew solution built by your local generator man would an option.

[Crossy]

This post http://www.thaivisa.com/forum/index.php?s=...t&p=2022245 will help you calculate your maximum demand and size your incoming supply requirements.

[Naam]

Swapping out the 3-phase units for single phase (they'll have a resale value so this may prove the most economical course of action), it's likely that only the outdoor units will need changing anyway, talk to your aircon man.

correct Crossy. fan of inside unit is single phase only. the most economical way is to change the compressor of the outside unit plus some rewiring. that's definitely cheaper than any rigging by converting single to three phase which might cause technical problems in the future.

looking at the total load your suggestion to get a 3phase supply is optimal, unfortunately not always possible

[Crossy]

correct Crossy. fan of inside unit is single phase only. the most economical way is to change the compressor of the outside unit plus some rewiring.

Thanks for the confirmation Naam, it seemed that that would be the sensible configuration (same indoor unit for single and 3-phase models) but I don't have a 3-phase unit to look at.