three phase isolation transformer 1) CE,CCC,ISO9001-2008 2)years of ... 0.1% 6 High Voltage Test: 2500V, 1 minutes at zero breakdown 7 Insulation resistance: winding-to-ground insulation resistance ≥ 500M ... % 4.installation sites should not seriously affect the strength of transformer insulating gas, steam, chemical deposition, dirt, dust, and ... in no time. three phase dry type isolation transformer