Adapter plug for a 230 volt 4 prong Dryer Outlet to a 230 volt 3 prong Outlet

You may not be able to do what you want. You need a two legs (usually red and black) and a neutral white and a true ground, not the same as a neutral. If you don't have that you have more work to do than just changing out an outlet.

You would connect to the two hots and the ground, not the neutral. If the Asko needed a neutral, it would have required a four wire cord.

See if you can't just buy a 4-prong dryer cord assembly and rewire the washing machine. The hookup should be pretty simple as all you are adding is a ground wire which would properly be attached to the washer metal frame at a convenient place. From your post it appears that you would be plugging in each appliance separately for use, but that seems rather inconvenient. Whatever, keep grounds and neutrals totally independent of one another...they serve different purposes. HTH

Joe

Since you need power for your washing machine, I surely would not wire to the dryer plug. There is no power in a dryer plug, unless it is in the socket. You could possibly build an adaptor that would be a dryer style plug, and an Asko style socket. You could then put the adaptor into the dryer socket, and then the washer plug into the adaptor.

The dryer plug would be removed from the socket, and set aside. Don't try to wire to the dryer plug, that would be a waste of effort.

Since you have the 220 volt power already available, consider having an electrician either put a four prong "dryer whip" on your washing machine. This strangely named thing is the power cord with plug on the end. Should be possible to put a four prong plug on your washer. Or, you may wish to ask him to wire a second socket next to the dryer socket. This second socket being three prong like your washer needs. You could leave them both plugged in at the same time, though you'd only have enough power to run one at a time. Easier than removing and replacing plugs.

The OP suggested the new device is 3 prongs, the socket is 4. It's doable.

Danger! Buying a four prong plug / whip adds a neutral.....

Thanks for all the responses.... just to clarify a couple of things. I currently have two hots, a neutral and a ground in the wall outlet. To wire the outlet for the new 3 prong washer, I just use the two hots and the ground, and I just leave the neutral out... is this correct?

I have actually wired a Y for the washer and dryer, so that I wont have to switch between the outlets, though I will only be able to use one machine at a time, without blowing the fuse, thought this doesnt concern me, since it is just me and my girlfriend doing laundry.

Correct

You are right and my apologies to the OP, I misread the question.

Which isn't going to be connected to anything. Big deal. Just wire-nut it at the appliance end (if it is, in fact, a 3-wire appliance).