220v to 380v converter

[littleyapper]

has any body had any experience in converting 220v to 380v ... i am being told that there is 2 ways of doing it static and rotary... which is best ... do they work... what kind of life span should i expect...i am talking of using one in a 30hp 5 deg c job...
380v is not an option .... should i just walk away...thanking you all in advance

[Peter_1]

Rotary means maintenance, static (= normal step-up transformer) is maintenance free and even a lot cheaper.

[Peter_1]

Sorry, lifespan, a transformer will do the job longer than you live

[35c08ar]

Hi everyone
@littleyapper the conventer you going to use depends sometimes on the motor youre going to feed( is it a big motor- i mean power?), becouse if the motor cooils are connected in a star U would need a very big conventer and if the coils are connected in a triangle the power of conventer can be much smaler .

[Peter_1]

..the conventer you going to use depends sometimes on the motor youre going to feed( is it a big motor- i mean power?),
It's a 30 HP in a cooling application

[Electrocoolman]

Rotary is the 'Old' method for obtaining a pseudo 3 phase supply from a single phase supply involving the use of a transformer, a 3 phase motor and capacitors.
A 'static' method using a transformer would assume that you already have 3 phase available...presume that this is not at 380v already....are 220v 3phase compressors not an option?

A modern VSD might be a way forward, but you will still need a transformer to step up the voltage for the VSD input.

[Peter_1]

I thought rotary was - I have an old Siemens one in my shop- a 3 phase 3 x220 V motor connected directly to a 3 phase 3 x 380 V alternator (with brushes)

If we have only 2 x 240VAC available and we need 3 phase 3 x 240 VAC, then we use a VFD (= a very cheap solution) Max available is +/- 2.5 kW.
2 x 240VAC to 3 x 400+N VAC isn't possible with this .

We then mostly use the English Invertek products for this. (I'm not working there :-) , only giving one possible solution)
Good product, good technical support and not expensive.

[Electrocoolman]

Hi Peter,
Yes I forgot about the motor-alternator rotary units.
Agree the VSD is the best option and that the 220v input will only drive a 220v 3phase output device....hence the need for a transformer on the input to up the input to 400v.

At present we do not know if he has 220v 1phase or 3 phase.....I suspect as he is in Ireland, it might be rural and single phase.
ECM.

[35c08ar]

thanks Peter_1 i dint noticed that motor is 22kW , and that changes everything, i never seen such a big conventer, and i think it is without sense to build conventer for that kind of motor. cheaper would be buy motor 22kW=30PH single phased if they producing such a thing. Imagine You all buliding conventer for 22kW even size of regural transformer is pretty big. Even if anyone would build that size conventer, i cant imagine the pull of power in littleyapper house, i can bet all fuses are out ;), heh 22kW motor feeded form three phase source gives you 34Amps on every phase , now when you feed motor from 220-240 it will give you about 100A on single phase. For what are you going to use suche motor ?? Can You tell if is not a secret. Maybe we can help you to find better solution. Huh?

[littleyapper]

thanks guys ... yes the job is in ireland only a 220v single phase supply 100amp max....i can go with two 15hp 380v scrolls...is this possible ?
has any body got contact details of that invertek crowd?
thanks again all scales ticked :)

[Peter_1]

http://www.invertek.co.uk/

[Electrocoolman]

Hi Yapper,
Might be worth contacting Schneider/Telemechanique - they've got good technical support.

As mentioned previously, I think you'll have to step your mains voltage up to 400v....this is fed to inverter, where you will have to disable the phase detection circuit in software. This should then allow you to drive your 3 phase motor.

Have you done your calculations?

15 hp = 11.25 kw
11.25 x 2 = 22.5kw

220v x 100A = 22kW

The lights might go dim!!!

[Frikkie]

Hello Littleyapper,

There is a inverter from Victron that I have installed in remote farm areas before which can make 380v 3 phase from 220-240v single phase. It comes as a 5 Kilowatt unit but you can keep adding many units together in series to get a bigger kilowatt output in single phase. You can also connect in parralal to get 3 phase supply from single phase input. They are not cheap for buying but they are a beautifully made unit, the ones I install have worked for about 8 years and no problems so far. I also use batteries and wind turbines as well as the single phase electrical farm supply with the inverter bank to make more input power. Also solar panels can work with these inverters but I don't know if it can with clouds in Ireland. The inverters are very intelligent and can make pure sine wave power from any source you can give them.

I sound like I get money from these people but I don't, only the other way around. They have a internet site at victronenergy.com/inverters-chargers/multiplus-12v-24v-48v-800va-3kva/ with lots of downloading and questions answered.

[littleyapper]

thanks again lads

[totalacedude]

they way i would go is get several smaller motor that when all on will equal the max output needed!

these motors / compressors (what ever they might drive) can then be connected to a run of the mill single 0-240v phase to 3 phase drive ie danfoss or the likes, as the output will still only be 240v (but 3 phase) smaller motors can be configured to run at this!

you can switch in the drives / motors as needed to suit the load!

look at it this way imagine your big motor is powering a compressor for the buildings air con.

your in bed at night and want to keep cool! you will need to run this big motor, even running this at low speeds will guzzle amps yummy!!

where if you had a smaller set of motors that could kick in and out as needed the savings are vast!

plus how i look at it dual voltage small 3 phase motors are abundant, and 240v single phase drives --> 3 phase output are also easy to come by and not at all deear!

just another idea!

ian