Hi Jack, That is unfortunate. We need to find a schematic for this spot welder or open it up and create one. It could be the secondary is just grounded to the ground pin. If so, we need to know how it is grounded. Ground loops, when such high currents are involved, can ruin your test equipment that is also grounded in the worst case. Strictly speaking there should be no ground current. However, I have seen equipment being damaged by ground loops when the setup was simply connected to the right connections, but in the wrong order of connection.
Better we step back and do a little more research on the circuit for the welder you have. I will look to see if I can find anything online. Bob On Sun, Aug 31, 2014 at 3:53 PM, Jack Cole <[email protected]> wrote: > Hi Bob, > > Unfortunately, I do not get infinite resistance. On the plugin ground > pin, I get 1 ohm on the bottom electrode bar and the top bar I get > different behavior. Specifically, when the top and bottom electrodes are > close together, but not touching, I get infinite resistance between the top > bar and ground pin. When the top bar is pulled up higher away from the > bottom bar, I get resistance. Is this a safety mechanism perhaps? I get > infinite resistance between the other connectors on the plugin and the bars. >
