pairing obits

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "colin.heath4 by way of Terry Fritz <twftesla-at-qwest-dot-net>" <colin.heath4-at-ntlworld-dot-com>

hi all 
        iv got some obits and want to hook three in parallel how do i do it if
i link all the earths then the one in the middle is a prob iv run two in series
with the earth centre tapped in effect an nst . the ratings are 7.5kv x2 30ma
so would this make it 15kv 60ma or 15kv 30ma if i dont get much joy with these
my mots are coming out with an inductive ballast 
 
cheers
colin heath