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#195858 - 08/26/10 05:38 AM Connecting 110V oven to UK power supply
UKSparks Offline
New Member

Registered: 08/25/10
Posts: 3
Loc: Southern UK
Hi all, my first post, so I hope it is in the right place!

I am a UK-based electrician with the following problem:
one of my customers has imported a double Maytag oven from the USA to use here in the UK.

He has asked me to connect it up, and not being familiar with the US wiring system, I am confused by the fact that I have 4 wires; red, black, white, and bare copper.

The bare copper is obviously the earth wire as I can see where it is secured to the casing, but other than that I am lost. The only wiring diagram supplied shows how to connect to a 3 wire or 4 wire system, but these are obviously US based.

I have contacted the manufacturer in the US, who refuse to help because the item has been exported, and their counterpart in the UK has taken the same attitude because it is an import, so no joy there.

I can only guess that I am also going to have to supply and wire in a 100V transformer (around 8kW probably, as oven is 7.2kW), but other than that any help would be appreciated.

Thanks for any pointers.

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#195859 - 08/26/10 07:27 AM Re: Connecting 110V oven to UK power supply [Re: UKSparks]
ghost307 Offline
Member

Registered: 05/09/05
Posts: 876
Loc: Chicago Illinois USA
The US system used in houses has 3 wires with 180 electrical degrees between them. Black and red are hot, and the white is a neutral conductor that gets connected to earth ONLY where the mains first come into the house.
Voltage from red to white is 120V, voltage from black to white is 120V and voltage from black to red is 240V.
From what little I know about the UK power system, you might not be able to do a direct connection. A transformer would need to provide that exact configuration in order to work properly. In addition, although the difference between the 50Hz in the UK and the 60Hz in the US shouldn't worry the heating elements, it might drive the fan, clock, and electronics completely batty.
Also, you may find that trying to figure a connection out might give the insurance folks a reason to deny a fire claim in the unfortunate case of something bad happening as the oven was not installed per the manufacturer's installation instructions.

I had a somewhat similar situation where someone wanted to install a 220V 50Hz machine that they saw in the Netherlands in the US. It was such a pain to make it work, get the Permits, get it approved and get it blessed by the insurance compaines that the idea was eventually canned.
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#195860 - 08/26/10 07:31 AM Re: Connecting 110V oven to UK power supply [Re: ghost307]
NORCAL Offline
Member

Registered: 09/25/02
Posts: 805
I saw the title & thought it was another DIY thread. :D:D

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#195862 - 08/26/10 08:24 AM Re: Connecting 110V oven to UK power supply [Re: NORCAL]
UKSparks Offline
New Member

Registered: 08/25/10
Posts: 3
Loc: Southern UK
Ghost, thanks for your quick answer.
From what you are saying, I'm guessing I would need a centre tapped transformer: 120-0-120, red & black to 120, and white to centre tapping (0), this would make sense as the rating plate on the chassis says "120-240V". Would this be correct?

Thanks for the heads-up on the insurance, I will mention it when I return.

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#195864 - 08/26/10 09:36 AM Re: Connecting 110V oven to UK power supply [Re: UKSparks]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: Estero,Fl,usa
The first thing you have to figure out is how much 120v load there is. The heating elements are going to be the main load and they will do just fine on your 230v. That is the red/black. Once you determine the 120v load that is left you can figure out what size auto transformer to connect to the white. It may just be the light and the clock. If you rewired the light to 230v by moving the white lead to the red or black (the one you have on your grounded phase) you may be left with the clock as the only 120v load and it won't work on 50hz anyway so you could just cut that wire and not have anything on the white.
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#195873 - 08/26/10 11:30 PM Re: Connecting 110V oven to UK power supply [Re: gfretwell]
noderaser Offline
Member

Registered: 03/01/07
Posts: 405
Loc: Portland, Oregon, United State...
Any particular reason your customer is so attached to this oven? Seems to me that it would be a great deal more expensive and troublesome to ship a large, heavy appliance overseas and then pay for installation of a transformer, etc--rather than using a domestic appliance. Surely, Maytag can't offer anything that Electrolux or similar could offer?
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#195881 - 08/27/10 07:56 AM Re: Connecting 110V oven to UK power supply [Re: noderaser]
NORCAL Offline
Member

Registered: 09/25/02
Posts: 805
Originally Posted By: noderaser
Any particular reason your customer is so attached to this oven? Seems to me that it would be a great deal more expensive and troublesome to ship a large, heavy appliance overseas and then pay for installation of a transformer, etc--rather than using a domestic appliance. Surely, Maytag can't offer anything that Electrolux or similar could offer?


I agree, and modifying the oven is not a good idea either, a transformer for a 120/240V supply that most US domestic cooking appliances require or better yet as said above, install the proper appliance made for the local market.

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#195883 - 08/27/10 08:24 AM Re: Connecting 110V oven to UK power supply [Re: NORCAL]
ghost307 Offline
Member

Registered: 05/09/05
Posts: 876
Loc: Chicago Illinois USA
The 120-0-120 transformer should give you the right voltage. The oven would also draw the same amperage as it would on this side of the pond.
You'd still have possible issues with the frequency on anything other than the resistive heating elements.

I also have to ask the same question as NORCAL; what's so special about this oven that they're so in love with it considering what a pain it may turn into??
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#195886 - 08/27/10 11:08 AM Re: Connecting 110V oven to UK power supply [Re: ghost307]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: Estero,Fl,usa
I don't understand why you would need to run anything but the 120v load through a transformer and you could rewire the light to 230 so you are probably left with the clock.
If it tags the line frequency for the timing it won't work anyway.
Unfortunately that may be the attractive part of the oven (the fancy control panel).
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#195888 - 08/27/10 01:59 PM Re: Connecting 110V oven to UK power supply [Re: gfretwell]
Alan Belson Offline
Member

Registered: 03/23/05
Posts: 1801
Loc: Mayenne N. France
Maytag are importing a lot of American white goods into the UK and have a couple of websites including 'Ask a Technician' and Spares. I bet that range is an 'anglicised' US product. A few carefully worded questions might elicit the part number of a suitable 50hz clock.
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