I bought a new stove and plug that is 50 amp. My fuses on my wire to the stove is 35amp. I want to see if I can just change out my fuses to make it 50 amp, but I dont know what the rating is on my wire going to the stove.
I think an easy way to measure your wire would be to: 1) Go to the panel box and shut off the breaker. Lock it out in case someone decides to turn it on again when you are working on it. 2) Take off the Faceplate to the receptacle. Pull out the receptacle and use a pair of wire strippers to measure the wire gauge of the wire. 3) If the wire is 8awg or smaller it should be replaced with 6 awg wire. Some info from the National Electrical Code: 210.19(A)(1) Branch circuit conductors shall (this means mandatory) have an ampacity not less than the maximum load to be served. Table 310.16 shows that 8 awg is rated for 40 amps and 6 awg is rated for 55 amps. 210.19(A)(3) Exception number 2; A neutral conductor of a 3 wire branch circuit supplying a household range shall have an ampacity of not less than 70 percent of the branch circuit rating and shall not be smaller than 10 awg. This is because on a 120/240 3 wire branch circuit the neutral conductor carries only the unbalanced current between the two hot leads. To calculate this multiply 50 amps X .70. So your neutral conductor needs only to be rated for 35 amps. An 8 awg wire would suffice for the neutral. What is the nameplate rating of your range?
If you need to know the answer its likely you don't have a decent crimping tool, without this you will only cause the terminations to burn up. Also the highest capacity crimp is still not big enough for most showers. The showers I have wired allow the right size cable to be terminated in connectors or terminal posts which are suitably large enough to allow the wiring to be wrapped without the use of crimps.
You must look at the wires themselves to first determine their gage and secondly, you must determine their length(run) between the fuse box and the outlet. The longer the run,the larger in diameter the wires must be, to handle the total amperage the appliance can consume at it's most loaded moment. These details are necessary to know so that you can work the necessary mathematics to calculate what size wire is needed to complete the job with a margin of safety. These calculations must include a recommended service supply box along with recommended fuse types.-Again, their must be a margin of safety involved. Better to over-build the wiring AND install the correct type of fuse.
Look at the wire going to the stove breaker in your panel. The size is printed on the wire. If it was a 35A breaker it should be #8 AWG. The bad news is that for 50A. You need # 6 AWG. (Those numbers are for copper wire.) Don't try to put a 50A. fuse in front of # 8 wire. It will overheat eventually with risk of fire.
Wire is rated for amps by the wire size. It would be unsafe to raise the fuse to a 50 if the current wire is sized for 35. You would be better leaving the fuse as a 35.
