Hi
I have a customer that just built a house in the US and is from England and would like to use a few small things (computer, lite, and train set) here in the US. What can I do as electrician to make these things work.

Computer should be no problem; most power supplies have a switch for voltage in the back, or are auto-sensing. Just switch to the US IEC cord and you're good to go. Of course, double-check the input ratings on the power supply (if not on the back of the case, it should be on a label just inside the case on the power supply if a tower computer)

Train set might be the trickier one, since it's going to be a variable DC transformer... Check the rating to see if it will accept 120; if not, replacing the transformer shouldn't set him back too much unless he has a really big setup.

If it's an incandescent light, it will WORK but will obviously be dimmer using 230V bulbs. Finding 120V bulbs that fit (assuming bayonet style) might be a challenge, so if he's really attached to the lamp, you could replace the socket... Or pick up a new lamp from Ikea or WalMart for $10.

Are 120/240VAC (step-down) transformers of a few hundred VA not available in the US?

As for the lamp, dump it, it isn't worth worrying about.

No dis-respect to the UK members here, but I have met, I don't know how many English people that have come over here EXPECTING the gear they bring with them to instantly be able to be plugged in and work, regardless of the difference in plug configurations.

One guy actually tried to claim for new plugs on his insurance.
Umm, OK.

You could make him feel at home by removing the receptacles from the loo

UK power is 230V 50Hz, with 3 wide square prongs. You could buy a few UK-style outlets, and connect them 240V 60Hz 15A, which would make plugging british-corded appliances easy to plug in, but code compliance becomes an issue since finding UK style outlets listed for 60Hz may be a challenge.

To "properly" do it, you could install a central frequency converter and 50Hz panel which then could distribute to outlets throughout the house. Very very few devices are frequency sensitive, though, and it's less of an issue running 50Hz equipment on 60Hz power than vice versa so this is just overkill. (going the other way, 60Hz transformers can saturate at 50Hz and must be derated to 80% if we want to run US stuff overseas.) Nothing you mentioned would be a problem at 60Hz. Computers and train sets rectify to DC, and incandescant lights are not frequency sensitive. The PC just needs a US cord (cheap) or plug adapter (cheap) and to flip a switch on the PSU to 115V. You only need to provide 230V power to the lamp and train, which can be done cheaply via small cord-and-plug transformer with no electrical mods required.

For reference, US military bases overseas often have 120V 50Hz US-style outlets installed for convenience. I've never had an issue, even with items only listed at 60Hz. Except when overloading those pesky shaver outlets in european hotel rooms, the ones fed from some tiny-ass isolation transformer that even my digital camera sends into a constant blinking charge cycle and can't be good for the battery. Man, you'd think they'd have a bit beefier transformer in those...

I have a bit of vintage radio and TV stuff from the U.S and often forget that it was designed for 60 cycles. Never had problems with any of it. Transformers don't run hot. Things with an electronic digital clock can be configured for either frequency as the clock chip has a pin you take high or low depending on mains frequency.
If I do eventually get something that really does need the 60c/s (clock, tape deck, or record player with induction motor),I'd simply buy an 12-120V inverter off eBay in the U.S and feed it from a 240-12VDC power supply.

Listing is not the only code issue. See NEC 210.6(A) through 210.6(A)(2).

FYI, I want to connect my computers to 240V. I'm expecting to "get around" 210.6(A)(2) via a UPS that exceeds 1440VA.


These devices will need a 2-pole power switch to be properly safe on North American (Edison style) 240V system. Every computer SMPSU I have opened up does have a 2-pole switch. Lamps need to be using a base that has no opportunity for finger contact to a live conductor, even if a 2-pole switch is used (e.g. no standard screw base, and maybe not even certain bayonet bases). My understanding from friends in Germany and Norway, because the Schuko plugs can be reversed, plugged in lamps must not have these kinds of bases there.

So, according to 210.6(A)(2), outside of the BS1363 Receptacle not being listed, my 2400W British tea Kettle is legal then.

210.6(A)(2) is unenforcible, though, as there is no restriction on cord & plug after it's installed. You can install it with the intent of using a 1500VA UPS or a 2500Watt tea pot, but as you won't be putting it in, you can't know whether he'll come back with a 700VA UPS or just plug a 60W luminaire straight into the wall, violating both 210.6(A)(1) and 210.6(A)(2). Regardless, the installation is perfectly safe.

I mean, it's impractical to retrofit new circuits after the drywall is up, so how many new homes are built with 240V welding/tool outlets in the garage/shop "just in case" before the homes are even sold? (OK, probably a small %, but I'm sure there are still quite a few. I did this in my house at least.)

240V coffee pot outlets in the kitchen should be mandatory

NEC doesn't prohibit the use of european listings, merely requires the listing be recognized by the AHJ. Does the BS1363 listing cover 60Hz? If so, it's "listed" and could be used.

I don't know how much attempt there is to enforce 210.6(A)(2). Maybe I or someone could submit a deletion for the 2014 cycle, explaining just this, and see what happens. I'd also add the "energy saving" aspect of it, too (it is real for some things like computers and fluorescent lights).

But I agree is it effectively unenforceable because it's so easy to just say it is there for some compliant purpose. I could put 6-15/20Rs all over the house and say they are for my 2400VA UPS protected computers that get moved around sometimes.

BTW, the North American 240V circuit would have the same balanced power effectiveness as described in NEC 647 for 120V. If all the audio equipment worked directly on 240V, NEC 647 might not be needed.


I agree with this, too. And there are other heavy duty appliances. I like wok cooking, which traditionally needs gas, which I don't like. Woks do very poorly on electric burner elements (worse on glass tops). But there is such a thing as an electric induction wok (Google finds them easily enough) that happens to work with traditional wok pans. The problem is you need somewhere between 2400 and 3000 watts to make them effective (though some wimpy ones for 120V are available).

I've been considering possible kitchen layouts: http://phil.ipal.org/ecn/2008-11-25/ks-group.html

Yeah!,
I bought one of them for my wife for her birthday (She loves Chinese food and stir-fry type things), it's been an absolute bonus for our diet, well worth the money and power usage.

If the house is being built and wired new, wouldn't the most practical solution be to just provide a few dedicated 15A 240V branch circuits to 6-15 receptacles where needed?

The only code issue then would be what those 240V receptacles are intended to supply, but if we're just talking about one per room at most, couldn't they be for (mumbles next part) individual space heaters? As stated above, nobody has any control over what anybody actually plugs into them afterward.

If you are only going to put one in a room, you better be sure you put it in the "right place". Way too many 120V outlets already "disappear" behind heavy furniture as it is. If you are going to claim a 240V outlet is for a window A/C, it really ought to be near the window. If it is for a space heater, it should be safe to put the space heater at that location.

I don't know if I would put 240V outlets in bedrooms, though I would not rule that out. But I do plan to put several in the kitchen.

I assume swapping the NEMA 6-15 for somthing more like this would be out of the question ?

To match the 84mm mounting centres, is this an option:

VERTICAL


HORIZONTAL


Good for 240V 15 amps

When I lived in the States for five years this quandary came up often and I posted questions on this board to ascertain the legalities of it all. A 240V NEMA 6-15 was the preferred option in the kitchen to power my 3 kW kettle. No RCD was required as it was not a 120V socket and as long as the socket was meant to power something greater than 1500 W? it could go anywhere reasonably required. According to those who inspect installations – this should pass inspection.

As for using a socket other than NEMA, particularly in my garage/workshop I deliberately avoided BS 1363 as the plugs are fused only on one pole and I felt this could present a safety issue on fuse failure with the other pole still live. I did however use the South African sockets (old BS546?) as the plugs were not fused – and coming from there, I had lots of them!

These 3kw "wok" can't compare w/restaurant's "wok hei" . The commercial version is 15kw . When gas price is high in mainland China, the 2kw single Induction cooker(~$30)sells like hotcakes

I would really think that the NEMA 6-15 is the clear choice for several reasons:

* Absolutely no question of code/listing issues from using non-UL/unapproved devices.

* Easy availability for replacements, fits standard U.S. boxes, uses normal faceplates in similar styles to those used elsewhere in the house.

* Easy to buy an NEMA 6-15 plug when needed, whereas if you run out of BS1363 plugs you're not going to be able to pick one up at the local convenience store.

* If you have a group of equipment that you really want retain BS1363 plugs on, you can just use a U.K. power strip and fit a 6-15 plug on the end of the cord.

I would not want to use a BS1363 on a North American 240V system, since the BS1363 design makes assumptions about which conductor is grounded (as exemplified by the fuse position). OTOH, the Schuko is more likely usable (if one can be found with UL listing or the local AHJ accepts the European listing) because no grounding assumption is made, and switched appliances have to treat both conductors as ungrounded.

If it's for a power strip, it should be OK, other than for the higher voltage MOVs wired between conductors and the grounding wire on surge protection versions. Some surge protection experts have suggested that MOV ratings be doubled, anyway (to reduce MOV burnouts along with the suggestion that the doubled rating won't affect most devices). So maybe that is moot.

Now I just need to find a mid-size UPS (between 2000 and 2800 VA) that can work on the North American 240V system.

There are plenty of server UPSes that run on 110/208, but they're not terribly cheap.

One reason they are not terribly cheap is they also are typically above the 3000 VA level. I found ONE UPS in the range I wanted, only to find no distributor had it in stock and later that the manufacturer (Liebert) had ceased production.