can single phase power be 440 v?

Sure, but there isn't much equipment that runs on 1 phase 440V (which would technically now be a 480V system).

Most 3 phase systems are configured in a Y winding pattern at the supply transformers (although marine systems may be different). In a Y system, any phase-to-neutral voltage will be lower than the phase-to-phase voltage by the square-root of 3. So on a 480V system, the phase-to-neutral voltage will be 277V. To get 480V single phase power then, you would tap power from 2 of the 3 480V phases.

But why you would do this, apart from wanting to feed another 1 phase transformer to make 240/120V 1 phase, is beyond me. I know of no motors, lighting or any ther loads that are designed to run directly on 480V 1 phase power.

All vessels that I have worked on have been 3 phase 415v, and single phase 240v systems for domestic power and lighting..............the last time that I saw 110v was on an older vessel in the late 50's.........and that was 110v DC.

However, being American it could be anything............I just thought...........just thought, mind you, that there maybe some international standard with shipping.

I only say this because I have never served on any international ship..............only Australian ships..............one other point, our systems run at 50 Hertz and American run at 60 Hertz...............and why!..........why!..........do the Americans persist with their own standard of imperial units...........do you ALWAYS have to be different to the rest of the civilised world. What does it achieve???

Although 50 Hz was suitable for operation of both electric lighting and induction motors in America, in 1890 Westinghouse considered that existing arc-lighting equipment operated slightly better on 60 Hz, and so that frequency was chosen.

It's funny because here in the United States we believe that it is the "foreigners" who end up changing around everything that we had invented and defined.

......United States we believe that it is the "foreigners" who end up changing around everything that we had invented and defined.

I think not, e.g. weights and measures..........I mean even when other countries were running with the Imperial system of weights and measures............what did the Americans have...............their own bastardised system...........the powers that be, never have never and never will change.........."whatever we do, we don't want an international system".............that would make things too easy..........we have to be different.........we are Americans.........we are great!!!!

I don't mean to be offensive when I say that..........not by any means..........its just not the way to have International Standards...........and believe me.........I feel it is required..........more so now, than ever before, because of the absolute crap that is being forced upon us by India and China..........and some of that crap is downright dangerous........they ought to shove it up their collective fundamental orifices!!!!!

Why?

Why we were first and you trying to catch up did not quite make it to 60.

Tongue in cheek!

Blame it on all the politician agreeing to disagree.

Yes, using a transformer (but what do you have that runs on single phase 440V?)

http://en.wikipedia.org/wiki/Transformer

If you are thinking of trying to use three single-phase outlets in parallel to get three phase, forget it it won't work (due to the phase separation being the same and not 120 degrees apart like it needs to be for a three-phase system).

http://en.wikipedia.org/wiki/Polyphase_system

Hi,

WEG motors (Brazil) manufactures their single phase motor with multi voltage configuration (220/440v). They obtain this by splitting the running winding and you therefore change the connection on the running winding for either a 220v or 440v single phase supply.

Personnally I've never come across a 440v single phase supply, but I'm sure there must be a demand for this for them to put the effort in to design and manufacture the motors in this configuration. http://www.weg.net/br/

440V single phase equipment is about as rare as rocking horse, er, teeth.

440V single phase power may be had by connecting across two phases of a 415V three-phase supply. The supply utility might not get too excited if the yellow and blue phases were used, which are usually lighter-loaded than the red.

Yes most definitely, and there are two similar single phase voltages that are reasonably commonly used in Australia

1. 415V single phase

2. 480V single phase

415V single phase (as others have already said) is what you actually have when you take a supply from any two phases of a 415/240V supply - this is erroneously called "two-phase" supply, but is in fact a single sine-wave 415V supply. It is very commonly used here to supply power to arc welders - they plug into a normal thre-phase outlet, but are in fact only using a single-phase supply.

480V (as somone from Brazil pointed out) is a reasonably common voltage available from SWER (Single Wire Earth Return) supplies used to distribute electrical power to isolated rural homesteads. The single HV supply is around 19 KV and the return path for teh HV is through the ground, so each transformer has a decent sized earth grid at teh base of teh pole to get a low impedance return path. The secondary side is a fairly normal single phase supply - same as anywhere else,except is can be configured for either 240V or 480V single phase. Each homestead has a single-phase transformer, each with a single HV winding and usually with two separate secondary windings, which can be connected in parallel to get 240V single phase, or connected in series with the centre-point grounded to get two 240V supplies with 180 degrees phase displacement, and 480V across the whole secondary winding.

Some single phase motors (as described - manufactured by WEG and others) have the same arrangment and can be connected to run on 480V single phase. In over 30 years I have only ever connected one installation in this manner - a shearing shed with a 5kW 480V motor to drive the old style overhead shaft sheep shearing gear - it is a leftover from teh steam engine days, then repowered by small diesel engines and now sometimes repowered once again by a single electric motor.

By the way, genuine "two-phase" supply systems did once exist - Ipswich railway workshops in Queensland had such a system - I am told it was two phases at 90 degrees, instead of three phases at 120 degrees that is now universal, and requires special proprietry generators and motors.

Almost all equipment that runs on a three phase supply, require a control cabinet, which is powered by a single phase step-down transformer, you need this to power contactor coils, control devices, PLC, some motion controllers, pilot lamps, push button common lines, flame monitoring systems, timers, counters, chart recorders, PC based equipment, temperature controllers and guess what else; and the primary of this transformer is powered by two of the main Lines, which makes a single phase 480 Vac for your control transformer.

Regards!

Your system already 440V. it is because most of the motor use are 440V, For domestic purposes why not, with the aid of step down single phase transformer 440V/220V/ with center tap110V, feed into the distribution panel intended for domestic only. with three wires run in every socket 220V/110 and lighting if necessary. a single phase 440V for domestic is not applicable since domestic equipment and appliances are rated mostly in 220 or 110V. If I'm not mistaken the load side of the system is in delta,3-phase, for balancing of loadside, so have the 440V in two wires which is single phase taken from the 3-phase system and single phase x'former 440V/220V/110V can be tapped for distribution panel isolated solely for domestic use. anyway there is a motor center for motors of rated 440V only which marine purposes priority on motors and sometime a dc motors another type of motor center panel. That's all, base on your information supplied, Goodluck