When you want to couple a single phase welding transformer to your generating set, make sure that your generator is much stronger (that it has more kVA) than your welding machine. Otherwise you will seriously damage your alternator and the capacitors (of single phase alternators) might explode. In all cases, we do not recommend to use welders on a generator set, unless there is sufficient overpower and a well calculated thermal-magnetic protection installed.

When you have a single phase invertor (electronic welding device), you can work more safely. But also here you need to check that there is enough overpower of the genset and that the sine wave of the single phase alternator has good quality (low harmonic distortion) not to damage the electronics of the welding invertor.