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110V sockets in a 220V home

Wond3rboy

Member
Hello

I was just wondering lately about making 110V sockets at my home to run a few appliances I had bought from the US. I use power converters at the moment and was curious as to from an electrical perspective, what would one need to do.

Should it be as simple as getting a transformer that converts the input voltage of 220V to 110V with the right wattage? I guess I would need to do something for grounding.

I was also curious about the effect on frequency, we use 50 Hz where as the appliance is supposed to be supplied with 60 Hz. I am actually not sure if my power converter does change frequency or not. I have one of the extension chord types

Power Converter (not this one specifically)

Am I thinking about it the wrong way?

Thanks in advance.
 

gophert

Well-Known Member
Most Helpful Member
CHanging frequency requires more than that can do. Talk to your local building inspector about electrical codes. I doubt they have a section on 120vAC in a 220vAC country.

Motors, induction heaters and transformers designed for 60Hz may run a bit hot and a bit weak on 50Hz.
 
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Wond3rboy

Member
Ah! Thank you for your reply.

I will look up the electrical codes for the 120V connection if there are any.

Yep, the frequency was what I was concerned about given that the appliances I need to run are a waffle maker, a blender and a mixer.
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
50 Hz runs OK on 60 Hz than the other way around. The blender and mixer are short duration. Look for 50/60 cycle labeling. Speeds will not be the same. Resistance heating not likely a problem. Could be, but not likely.

Since these seem to be located in the kitchen or one room in the house, There probbably isn;t an issue of putting a transformer near the main breaker box and create 120 US style power. Either 120-0-120 split phase or some 0-120 stuff.
Split phase might actually be better. Kitchens in the US are supposed to get at least two 20A 120V GFCI protected outlets.

In the lab I worked in. we had to create "German power" for some special furnaces for a tenant researching Aluminum foam.

The AHJ (Authority having Jurisdiction) is the people you have to talk to. Buy putting in a 240 20A to 120-0-120, you would get two 20A 120V outlets. You would need to bond the 0 point to your ground and create a neutral.
 

rjenkinsgb

Well-Known Member
Most Helpful Member
Just get a commercial 110V power tool transformer and hide that in a cupboard.
They are ready-cased with proper protection etc. and give out 110V with a centre tap to ground, so only 55V to earth.

You can easily get one rated 2000 - 3000W for less than 100- on ebay, they are far better value (and quality) that travel-style voltage converters.

eg.
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
Take a look here: https://www.ato.com/20-kva-isolation-transformer-single-phase

Not saying it's right or wrong, but this looks like an industrial transformer that would be used with a piece of equipment.
it is 50/60 Hz and can be aluminum or copper.

What might be done in an industrial setting for lots of circuits is to permanently mount a transformer and enclosure below the breaker box.

So, for 20A of 120V 50 Hz multiple outlets, but 20A total, that might be easy. Two might be harder.

Putting in 120/240 split phase 50 Hz might be harder yet.

Just a note: The US follows the NEC

There is what's called a main lug panel and a main breaker panel.

Main lug panels separate L1, L2, N and Ground, but don't have a breaker to turn everything off.

Main breaker panels do, but N and Ground are not separated. In new panels, they usually can be separated and a ground bar kit installed. The main breaker panel (say 200A) acting as a main lug panel can be fed with 60 A breaker. The panel would only be rated for 60A.
 
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Wond3rboy

Member
Thanks so much guys! This is a really neat idea and saves so much hassle. Cant believe shipping screws this up for me. I have a friend in the US who might travel back home. I will still see if I can find someone in the UK.

But you have given me a very good idea, there are stabilizers here which output 110V too in addition to 220V. The one with the highest power rating I can find and is affordable is 1500KVA. I guess one can use these appliances with them. I will probably need to get one with a larger power rating, something like 2000 to 3000 Watts.

Stabilizer I am talking about
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
The mention of "Servo motor" essentially means a variable motor controlled auto-transformer. See https://variac.com/staco/PDFCutSheets/VT Schematic.pdf (No motor). They are usually single winding with a brush, non-isolated. It's important to fuse the wiper. They can be configured as buck-boost.

Transformers and motors are rated in VA or Volts*Amps. For resistive loads, this is equlivlent to Watts, but for inductve loads (motors) it isn't. Initially, the service needs to be able to supply a brief burst of current equal to the resistance of the motor winding, A little rule, like the "current in an inductor can't change instantaneously" comes into play.

The US doesn't put fuses in the cords like the UK does.

What's the VA rating of your USA appliances and what is the maximum current a typical UK outlet can deliver?
Would you have all of the USA devices operating at the same time?

Now, you sort of, see the need for two 20A 120V services in a kitchen. Microwave ovens might be separate because they are close to 1500 VA. Electric stoves are usually 240V and would have a separate service. Some stove tops and ovens even if gas might require a bit of 120 VAC.

The NEC would like you to have what's called 4-wire 240 for your electric oven and electric dryer, This has L1, L2, N and Ground. it's (L1)120V-(0VAC)(N)(G)-120V(L2) which is just a center tapped 240V transformer.
For a 0-120V secondary, your secondary (N) would get bonded to ground as a separate wire.
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
Putting stuff into another perspective, the US has 15A and 20A 120V receptacles for home use. 15A plugs will mate with a 20A receptacle. No fuses in the cords.

1 HP or 1.5 HP would be the max HP used in one of those plugs.

The VA rating is largely irrelevant because the breaker is attached to a 60-200A source through a 15 or 20A breaker. The time-delay-curve lets a fair amount of brief current to be drawn. When you are sizing transformers or generators, the VA rating matters or a motor may not start. So, VA really determines starting and FLA or full load amps, determines running currents at max load.

When sizing wire, the NEC also cares about continuous loads. An oven in a restauraunt is continuous, but an ovenin a residential setting is not, so wire sizing is relaxed for residential. We generally don't want more than a 3% drop in voltage.

In the home, a 20A circuit is wired with 12 AWG and 15A is wired with 14 AWG wire.
 
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Nigel Goodwin

Super Moderator
Most Helpful Member
Hello

I was just wondering lately about making 110V sockets at my home to run a few appliances I had bought from the US. I use power converters at the moment and was curious as to from an electrical perspective, what would one need to do.

Should it be as simple as getting a transformer that converts the input voltage of 220V to 110V with the right wattage? I guess I would need to do something for grounding.

I was also curious about the effect on frequency, we use 50 Hz where as the appliance is supposed to be supplied with 60 Hz. I am actually not sure if my power converter does change frequency or not. I have one of the extension chord types

Power Converter (not this one specifically)

Am I thinking about it the wrong way?
Yes, completely - just buy proper appliances for the country you're in.

American appliances probably don't meet UK safety standards, and shouldn't be used.
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
Example:

You mount a flange enclosure on the wall that has an aluminum back panel. You bring in enough power for say 30 kVA.
You can split that up into two 15A breakers. e.g.https://www.asi-ez.com/member/x557-GFCI-Circuit-Breakers-RCD-Breakers-RCCB-Breakers-DIN-Rail-Mount.asp and connect to two transformers. Each could feed two US style outlets.

Legal? Don't know.
 

MaxHeadRoom78

Well-Known Member
Should it be as simple as getting a transformer that converts the input voltage of 220V to 110V with the right wattage? I guess I would need to do something for grounding.
In N.A. if using an isolation transformer, one side of the secondary has to be referenced to earth GND, this then becomes the connection for the Neutral and the Earth ground conductor,
As mentioned, N.A. has been 120/240 since end of WW11.
When I did my training in the UK, we had to accommodate alot of US service families living in off base housing, that had brought all their appliances with them.
Problem is it is so long ago I don't recall many of the details as to how we accommodated everything.
At that time, the 13a ring main had just become the popular norm, which as you know has the 13a max fuse in the plug.
BTW, many N.A. Kitchen appliances, hand tools, have Universal motors which are not frequency sensitive.
( I brought mine the other way, UK. to Canada).
Not only are the regs there different now, the wire gauge has gone metric! :D
Max.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
In N.A. if using an isolation transformer, one side of the secondary has to be referenced to earth GND, this then becomes the connection for the Neutral and the Earth ground conductor,
As mentioned, N.A. has been 120/240 since end of WW11.
When I did my training in the UK, we had to accommodate alot of US service families living in off base housing, that had brought all their appliances with them.
Problem is it is so long ago I don't recall many of the details as to how we accommodated everything.
Didn't the bases themselves run off generators, so didn't use the UK infrastructure? - a friend of mine bought a LARGE generator from a US Base - it was on a trailer, used a two stroke diesel engine, and if I remember correctly was in the 100's of KVA. Again, as far as I recall, he bought it at the auction, then immediately sold it on.
 

MaxHeadRoom78

Well-Known Member
Didn't the bases themselves run off generators, so didn't use the UK infrastructure? -
I meant the off-base rented houses, When I came to Canada, I leased my place to the Base Housing officer for three years.!
There was quite the US community in our local area, I partied with quite a few!
Max.
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
I think I've seen one sign in the US where they had a metric measurement for 6 feet (social distancing requirement) also on the sign.

I still like using "body parts" to make estimates. Walk to to heel for feet or use 1 foot floor tiles or 2'x4' ceiling tiles. Thumb to knuckle for the inch.

Knots, came from real rope knots.

Then there is metric and English tons.

My boss said any number had to be between 1 and 10, so 1 nA

Angstroms was a pain too.
 

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