What would most likely happen if you wired in an oven the wrong way, ie double positive, or double negative, or positive to negative and negative to positive?
In the US, regular lights and outlets use 120VAC, and large appliances run on 240VAC. Some large appliances need both 120VAC and 240VAC, and they will use 3 or 2 wires respectively.
For a 240VAC only appliance, you will have two colored wires which are typically red and black. There will be two screws on the appliance, and it doesn't matter which wire goes to which screw (there will also be a bare ground wire and associated screw, but I'm leaving that out of the discussion). The two wires are both "hot" (not positive or negative) and have a voltage of 240VAC between them and you really can't hook it up wrong.
Other appliances need 120VAC and 240VAC. For instance, newer ovens might use 120v for their electronic displays, lights, and controls, but the main heating elements will run on 240v. These appliances need three wires which are typically colored red, white and black. The white is referred to as "common" and it must be connected to the correct screw. The voltage between red and white and black and white is 120v, but the voltage between red and black is 240v. Red and black are interchangeable.
If you happened to connect the red to the "red" terminal (terminal meant for the red wire - it probably won't be red...) and black to the "common" terminal, you would be supplying 240v to a part of the appliance that needed 120v, and something would break. You would hope that a fuse or something easily replaceable would break, but there's no guarantees. The oven could be cooked.
Hey buddy just so you know people from America have a 120/240 system.
Meaning we have two legs of power coming in each current 120 volts on them when they're combined together they make 240 that is why when Americans travel to European countries including Germany we have to take transformers or smaller less time used convert. we can charge are laptops because the transformer built into the machine is able to take up that voltage then you just need an adapter.
Here in the States we have what is called a neutral you guys probably do not have this and that's you have two hots going to everything you need instead of just one hot and then neutral like we have, because of this reason you should only have three wires for your stove go and only three places wires to attach on your stove two of them will be your hot and one of them will be your ground the ground one should be pretty easy to identify because it should not have any physical protection from the metal on the oven in the first place. If there's any insulation that prevents the connection between the two screws and the oven those will be your hot on your oven and has to be grounded so that if there's ever a short you don't fry well cooking your french fries.
If you have any doubts about this hookup please review your owners manual or contact a license electrician in your area. * it's worth it*
In a 240v oven outlet you have two hot 240 wires and one neutral (white wire). The lights, timers and circuit board use 120v by tapping the neutral (white) and a hot leg. If the neutral is connected the hot leg then you may burn out the 120v circuit board, lights and timers. The operative word is "may" depending on which leg was cross wired and which one is actually used, 50-50 chance. What will happen is the burners and elements will only have 120v and not work well.