convert 220 v plug to 50amp rv plug

ktmrfs wrote:

One BIG issue is that as you point out, the neutral
in these old 3 wire systems (and some 4 wire as well)neutral was often NOT the same gauge, it was smaller.

That was, in fact, the primary purpose for my post..

IF all 3 wires in a 3 wire outlet are the same size, a 4th wire (Safety ground) can often be added fairly easily. Not code, but still safe.

But if the neutral is reduced size.. There is no safe way save running brand new cable.

I see many things done that are less than safe.. This thread covers a bunch of them.

Now, to the O/P (Since the guy I'm replying to clearly understands this)

here is what happens in a 120/240 system and why the neutral needs to be the same size (or larger) than the hots.

The advantage to the dual voltage system is this.

Let's assume there is 0.25 ohm resistance in each leg between your appliances and the transformer.. That means that at 10 amps you are loosing 5 volts 2.5 volts each way.

So 120 volts is now 115 volts.

But you turn on the other A/C, and "Balance" the legs.

now that 115 volts magically becomes 117.5 There is no longer any "Return current" the neutral (it is being used a 2nd time and returning through the other hot).

BUT.. What happens if everything you have turned on (one A/C, the Microwave, and perhaps some other stuff) is all on the same leg?

now you are pulling 30,40,50 amps all of it running through 1 leg and the neutral.. IF the wires are all the same size, NO problem (Save the voltage drop is greater)

If the neutral is smaller... .. Well the Fire Department still makes house calls.