Ok, here we go again with me experimenting. I know the USA 700w mercs are different than the uk ones, ours run at 240 arc voltage and requires a powerful 450voc to strike. 1kw us mercs are like that too. Here's the point. I've noticed that 700w ballasts in 120v flavor are very rare, and I heard that you can actually change the cap values on 1kw ballasts to use 700w mercs. So I found this ballast. From what I can see in the potato pics is 120/208/240/277v. 9.8/5.6/4.9/4.25a, cap 24uf 450v min. I don't know the mathing to determine the new cap value for a 700w USA merc. Any ideas? Thanks.