MPG heat-shrinkable hi-volt bus-bar tube 1min phase-phase power frequency withstand test-->42kV no flash and no breakdown Phase-phase impulse voltgae test-->75KV 15 times phase-phase impulse withstand test of the positive and the negative ectively, no flash and no breakdown 1min phase-earth power frequency withstand test-->42kV no flash and no breakdown Phase-earth impulse-voltgae test-->75KV 15 times phase-earth impulse withstand test of the positive and the negative spectively; no flash and no breakdown Temperature rise test-->the temperature rise of the copper Should not over the bare copper; s when the insulated tube shrunk in the below; surrounding. Withstand test of the heat-shrinkable tube-->20kV, 1min no breakdown