6
If it is a 480v 3 pH machine, #4 wire will be fine.
The wire size is large enough to carry the load current and that the cord is properly voltage rated.
500 mcm (or 500kcmil) conductors are used for 400 amp 480v single phase or 3 phase systems. The wire AND THE TERMINALS must be rated for 90o Celsius.
2 copper
The size of conductor needed will be a #14. It should be copper and have an insulation factor of 90 degrees C. The fact that it is a three phase load does not enter into the calculation of the wire size.
If it is a 480v 3 pH machine, #4 wire will be fine.
The wire size is large enough to carry the load current and that the cord is properly voltage rated.
Up to about 100 ft the size of the wire is determined by the max current and not the distance. A 90 amp supply needs #6 wire. <<>> A #2 copper conductor will limit the voltage drop to 3 percent or less when supplying 90 amps for 75 feet on a three phase 480 volt system.
Just replace the cord. Your manual has instructions.
Yes, no problem at all going to a larger ampacity of wire. Larger size wire yes, smaller size wire no.
First off, it is not a 3-phase range. It is a single phase 110/220V range with a cord lacking a ground pin. Also, it is not a 4 phase outlet. It is a modern 110/220V outlet with a ground pin. To upgrade your range, go th the hardware store and buy a new 4-prong 50A 110/220V cord with a ground. Remove the old cord, and wire in the new cord. If the old cord was flat without a color code, the two outside wires are the hots (red and black on the new cord) and the center wire is neutral (white on the new cord). If the neurtal lug is bonded to the chassis, break the bond. The green wire in the new cord grounds the chassis. Connect the green wire to a convient screw in the chassis, if a dedicated green ground screw is not provided.
25 percent larger wire for 50 feet.
500 mcm (or 500kcmil) conductors are used for 400 amp 480v single phase or 3 phase systems. The wire AND THE TERMINALS must be rated for 90o Celsius.
#16 <<>> To load an extension cord to 1725 watts depending on the length of the cord, the bare minimum should be #14. A better size cord and my recommendation would be a #12 wire size extension cord.
2 copper
The wire size depends on the amperage, not the voltage. The fact that the welder runs on 440 volts does not affect the wire size! You need to ask this question instead: What size wire do you need for a three phase welder on an eight foot run if the nameplate amps are 45A?
To answer this question the voltage and the amperage of the cap must be stated. Then the termination letters can be given.