111111111111 Dear Mr. Rob Covers. Here are the answers for your questions.

1, Q: What is the voltage rise time for 0~1,000volts?
A: For our surge tester, the rise time of the test impulse is about 0.2~0.5us. The rise time is mostly depends on the devices that is used as the high volage ON/OFF switch.

2, Q: What voltage do you recommend as the best testing voltage?
A: The testing voltage set on the surge tester is only related to the using voltage of the product(EUT: Equipment Under Test), for example, if the using voltage of the product(same as EUT) is 220V, Then the suitable test voltage come up from the formula under.
Fm1, Test voltage ={(operating voltage of EUT*2) +1000V}*Compensating loss voltage while testing
Fm2, Tv={(220V*2)+1000V}*(1.3~1.6) Tv= Test voltage that is set on surge tester.
1000V= Constant voltage(It means even if the operating voltage of EUT is less than 1 volts, the impulse voltage always comes out more than 1000volts.
 
3, The motor(EUT) application, Wattage, number of winding turns, phase resistance, and if it works with AC or DC, and other conditions do not depend on to set the test voltage of surge test, it may sound rather strange, the test voltage(surge test)is related to only the using(operating, or generating) voltage of the product. Thanks a lot.