Originally Posted by corgan
When checking 110 receptacle with a volt meter what should it read. I know the 220 read 110 from hot to ground and 110 from negative(white) to ground
Corgan, click the link below and then click on the outlet testing tab on the lefhand side.
Now, near the top of the page they have diagrams of a 220 volt 50 amp outlet and a 120 volt 30 amp outlet. Beside each diagram, it explains what voltage you should have across which terminals.
Having voltage from White to Ground in your 220 doesn't sound right if you had a four prong welding outlet. Was yours a three prong 220volt welding outlet? If so, I think I know what went wrong as there is no neutral in that setup.
A three prong welding outlet has two hots (each 120 volt) and a ground, with no neutral. If you tried to hook these same three wires to a 120 volt travel trailer outlet, then you kept it 220 volts. You'll have to have a neutral before you can properly wire up a 120 volt TT-30R.
Click the welder service tab at the same link below, which will help explain this. It also tells you how to rewire everything at the breaker box to use your welder circuit for the travel trailer. You have to change one of the hot wires to a neutral.
Converting the Welder (6-30R or 6-50R) service over to a 30-amp 120-volt RV service Remove the Double pole breaker and replace it with a Single pole 30-amp breaker. This service requires 3 wires 1 Black (Hot lead) 1 White (Neutral) and 1 Ground. One of the hot wires will have to be made into Neutral wire. Use white tape to identify it for future reference. Install a TT-30R receptacle and its ready to go.