voltage question for overseas and knowledgeable people

[Ansil]

i need help from people overseas about your power. what i need to know is this. (i know you use different plugs. but is it orientated the same way is what i wish to know.)

my shop has a 240 plug in it (well aproximately anyway 240 as it isn't quite regulated well here depens on wiring and stuff) and i was wondering. this.. i can take a 240 plug and knock off one of the extra lugs on it so it doesn't give me the full 240 it actually gives me just the 120 since you have the two hots parralled and the two neutrals grounded (well thats how it is in the states anyway.) so what i want to know is. if i am building an amp for someone overseas. would this be a terrible problem as it all seems to work great here on the amps i have tried it on. and i really dont' have a 240 transformer yet. i mean asl ong as i get the correct pin orientation from someone in australia wouldn't this work??? any takers

[Eddie]

Hi Ansil,

I have never heard about  that option before. They use a stepdown transformers.
Your way would be easier an cheaper but nobody uses that possibility (if it is a possibility???).


Eddie

[R.G.]

so what i want to know is. if i am building an amp for someone overseas. would this be a terrible problem as it all seems to work great here on the amps i have tried it on. and i really dont' have a 240 transformer yet. i mean asl ong as i get the correct pin orientation from someone in australia wouldn't this work??? any takers

It's quite likely either not to work or to fry into a nice, sizzling mess.

The most efficient way to transmit AC power is three phase. Minimum wire size for max power transfer per pound of conductor. Except for some unusual situations, all bulk power is shipped around as three phase. Each phase is 120 degrees apart.

Not many power users use three phase. All us normal people use single phase. What the electrical companies do in the USA is to ship 3 phase (usually at about 13kV) out to the step down transformers, where it's made into either 208 delta wired three phase or three 240Vac single phases. Since the national voltage standard (oops, gentleman's agreement between power companies) is 120Vac single phase, they center tap the 240 into two 180 degrees out phases.

The CT becomes "neutral" and is connected to that copper wire that runs down to the bottom of where the pole is buried in the ground. The two 120V phases are run into the premises along with a husky neutral conductor that is only pulled away from real, honest-to-God zero volts by whatever unbalanced current flows back from the premises. The electrician tries to balance the current uses inside the premises by assigning about half the breakers to one 120V phase, and the other half to the other phase. If everything is balanced, there's no neutral current.

240Vac is obtained where needed by taking power from the two opposing 120V phases, and getting no return neutral current. That's why it works when you knock off one tab - you're connecting the amp across the same 120Vac single phase it used to be getting.

However, every country has national standards about wiring. I just brought up a web page on Oz's wiring, and it looks like they wire 240V 50Hz like we wire 120V 60Hz - line, neutral, and safety ground. If that's the case, you'd be setting up a safety hazard at best by removing one prong, since two of the three prongs to knock off are neutral  and safety ground. Knocking off the active/hot lug would provide no power to the amp, and nothing would happen.

It's best to NOT second guess country power requirements. You can get the user dead, and/or yourself sued.  Neither are pretty.

[Paul Perry (Frostwave)]

:!:  :!:  :!: DON'T DO IT :!:  :!:  :!:
What you have in a 3 pin 230V plug, is active, neutral, and ground.
Cut oof the active and you have nothing (provided the house is wired right). Cut off the neutral & you still hae 230, probably the gear will not go because the transformer is trying to go back via the cut neutral. In any case, no good can come from it. www.jameco.com have cheap transformer converters.
Incidentally here's a good guide to power around the world:
http://www.korjo.com/adap.html

[Lonestarjohnny]

Hey Ansil, Build 1 for Russia, You need 366 volt tranny's, or at least that's what they finally got it dropped down to for my 276 man camp i setup on 1 of my venture's oversea's.
Johnny

[Paul Perry (Frostwave)]

, Build 1 for Russia, You need 366 volt tranny's,
Johnny

I think normal Russia is 210v, the 366 would correspond to the 'three phase' power for very high load applications.

[Ansil]

thanks very much i didn't think it would be very viable and i figured it had some flaw that i wasn't thinking of yet.

of course since i am back on my vampire schedule i tend to be sleep deprived while typing all of this. until i get some money up to ship a computer.  

i thought i would ask the experts first.  and i knew.  that R.G. was in there i was counting on his reply.  thanks to all the others as well i thought i would ask here cause i got no response from others and i wasn't going to send an amp like that out anyway.

just a thought as i was building a plexi head for a friend on the barter system and trying to find a proper transformer for little or no money is very hard.  

i have multilple high voltage transformers but i diddnt' think he would want to use one of those adaptors and i wasn't sure how much a tube amp would need amperage wise. i mean i could sit down and do the math sure but i was feeling lazy at present moment and didn't feel up to the task as well as i have misplaced my calculator and i hate doing it in my
head.

that and i was trying to figure out the best way to setup the amp and bias it properly at the shop and then ship it off to him..  probally would get off in the shipping anyway. i already built the board and got the filter caps and rectifier built measured the voltage and amperage with the 120 line in the shop. everything is functioning properly just got to scrape and get the output transformer and two more tubes. i have the 50watt model tested out on "borrowed" parts and it is quite nice.  

he wanted an all stock unit so thats what hes getting however i like the little traynor i modded for more gain and more bass response over all it has 2 distinct channels now.  the 2nd channel is dropped to a .0056mfd  cap  from a .022mfd.  and has a 1mfd cathode cap.  the first channel has a .39mfd cap from a .022mfd  and has the stock 250mfd cathode cap.  raised the resistor to 1k on both of the channels and added a 560pf to the stock 270pf treble cap to take some of the shrillness out of the amp.  still a very bright amp.  

anyway sorry for rambling. back to work at the shop.  i have the first 5' by 7' piece of glass installed in the shop. as well as the first 12 feet  of the divider wall.  

finally got 2 desks one for soldering one for beating things a few odds and ends. a drawer full of tubes.  a few amps being tested and repaired in the repair section a couple of extra tables three couches a bed (i call it storage room personally i built a little room to get away from it all and i use it for storing stuff on the bed. go figure i sleep on the couch anyway lol.)

lord willing i am getting a drill press and building another frame ot hold the second piece of glass and some wood to finish up the retaining wall and the shower section. might put a glass door on it i recently came into alot of glass. also i have some extra plexiglass if anyone would like a little. i scavenge the glass comapny a couple of miles away.  

i stained my guitar and it came out horribly so i had to strip it. i have a few pics up of the shop from the shows we did i will have to upload them to photobucket so you can see what it looked like.

love peace and chicken grease.