Have just purchased a new electric range and plug on it is a 50 watt 4 pronge plug , the wall plug is a 30 watt 4pronge plug in, 50 amp does not fit in 30amp plug because one of the posts on the plug is L shaped, do I just have to change the plug in to 50amp receptical or do I need to also add a 50 amp fuse to breaker box and if so just have to replace 30amp breaker with 50amp or does the wire from box to plug have to be changed as well

I would presume the wires to the existing range is 30 amp but you will need to check. A 10 /3 is 30 amp. An 8/3 is 50 amp. Do not put a 50 amp breaker on a 10/3, you are looking for serious potential fire hazard. . A qualified guess would be you need new wire, breaker and outlet.

Good morning,

Let's start ths way, please. Are you replacing a cook-top appliance wit a range and oven combiniation?

You really need to check the e;ectrical specifications of the new range. 50 amp seems a bit high. I would suspect that you need a 40 amp circuit, but I don't have my code book handy and you did not post the requirements.

Next, is this range being installed in a home owned by you or this is this rental property.

My best suggestion would to get several qualified electricans to bid on this work. You will have to replace the entire circuit from the panel box to the outlet, including a new 4 wire cable sized for the required amperage. A breaker for the panelboard sized for the proper amperage.

You also need to decide if you are going use a free standing receptacle or a wall mounted receptacle.

Oh, and don't forget to install the "Tip- block" safety.