The table below indicates the test voltages required to test the
rotating machines.

Operating Voltage of Rotating Machines 
AC/DC H.V Test Voltage 
Surge Test Voltage 
120 V 
1,240 V 
1,800 V 
240 V 
1,480 V 
2,200 V 
440 V 
1,880 V 
3,000 V 
660 V 
2,320 V 
3,500 V 
2.3 KV 
5,600 V 
7,000 V 
3.3 KV 
7,600 V 
10,000 V 
6.6 KV 
14,200 V 
20,000 V 
11 KV 
23,000 V 
30,000 V 
23 KV 
47,000 V 
49,000 V 


NOTE:
Many other formulas are also used to calculate the test voltages for AC form wound coils. These
are generally based on experience and theoretical arguments about the distribution of voltage
in a coil, and the entire winding. The formulas are difficult to apply because of great diversity
of coil specification and charachteristics.
The other popular formula below also states the Min and Max test voltages:
MINIMUM TEST VOLTAGE = Number of Turns X 500
MAXIMUM TEST VOLTAGE = Operating Voltage X 1.5
